CELL THE UNIT OF LIFE

INTRODUCTION: EXCEPTION OF THEORY Cell is a basic unit of life and It is I. Virus/ Virion/ Bacteriophage, considered as structural and functional unit II. viroids of an organism. Robert Hooke (1665) III. prions discovered cell. He first observed the cell in a piece of dead cork cells. He described cell SIZE AND SHAPE OF CELL in his book “Micrographia”.

Leeuwenhoek (1674) first observed animal SIZE cell and used the term “Animalcule” for it.  Cell differ greatly in size, shape and The study of cell structure is called cytology. activites. The study of cell structure, function &  Mycoplasma laidlawii (Smallest cells) reproduction is called . Only 0.3 m in length [PPLO (pleuro Robert hooke is known as ‘father of pneumonia like organisms) is a type cytology’. of mycoplasma having the size about Swanson is called the ‘Father of modern 0.1 m)] cytology’  Bacteria  3 to 5 m  Largest unicellular Eukaryotic cell - CELL THEORY Acetabularia alga - (10cm)  Largest isolated single  cell ostrich  In 1838, Malthias Schleiden, German egg botanist, examined a large number of  Human red blood cell  7.0 m plants and observed that all plants  Longest animal cell  nerve cell are composed of different kinds of (Neurons) cells which form the tissues of the  Longest  ramie plant. At about the same time, (Boehmaria) Theodore Schwann (1839), British Zoologist, studied different types of animal cells and reported that cells EAGLE EYE had a thin outer layer which is today known as the ‘plasma membrane’. He 1. Smallest cell has higher surface area also concluded, based on his studies to volume ratio on plant tissues, that the presence of 2. Virus is acellular and connecting link is a unique character of the between living and non living. plant cells.  Schwann proposed the hypothesis SHAPE that the bodies of animals and plants  The shape of the cell may vary with are composed of cells and products the funtion they perform. of cells.  They may be disc-like, polygonal,  Schleiden and Schwann together columnar, cuboidal, thread like or formulated the cell theory. This even irregular. The shape of the cell theory however, did not explain as to may vary with the function they how new cells were formed. Rudolf Virchow (1855) first explained that perform. cells divided and new cells are formed from pre-existing cells (Omnis cellula-e cellula). He modified the hypothesis of Schleiden and Schwann to give the cell theory a final shape. Cell theory as understood today is

(i) all living organisms are composed of cells and products of PROKARYOTIC CELLS cells. Cell that bears naked genetic material i.e. (ii) all cells arise from pre-existing nucleus is without Nuclear envelop is known cells. as prokaryotic cell.

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The prokaryotic cells are represented by cell wall and innermost cell bacteria, blue-green algae, mycoplasma and membrane. PPLO (Pleuro Pneumonia like Organisms). (vi) If these envelopes are stained by Gram They may vary greatly in shape and size. The stain (Crystal violet) then they are four basic shapes of bacteria are bacillus called Gram positive bacteria while (rod like), coccus (spherical), vibrio (comma other those don’t have are called Gram shaped) and spirillum (spiral). negative bacteria. (vii) , a polysacchride envelope forms either loose sheath slime layer or thick and tough structure capsule. (viii) Plasma membrane extensions like vesicles, tubules and lamellae not only help in cell wall formation, DNA replication, and distribution to daughter cells, increase in surface area

but also form some specific structure

for specific function like mesosome for They have following characters : respiration (analogous to mitochondria) (i) Like eukaryotic cells, they are and chromatophore for different in shape and size but small (analogous to ). than eukaryotes & divide rapidly. (ix) Cell wall form some filamentous (ii) Naked genetic material is called extensions called . It consists ‘genophore’ and area in which it is of filament, hook & and present known as Nucleiod. helps in locomotion. Filament is (iii) Genomic DNA is circular & termed as longest portion and extends from the single chromosome. cell surface to the outside.

(x) Besides flagella, Pili and Fimbriae are

also surface structures of the bacteria

but do not play a role in motility. The

pili are elongated tubular structures (iv) Beside genomic DNA, small circular made of a special pilin protein. The DNA is also present in many bacteria fimbriae are small bristle like fibres called plasmid. The plasmid DNA sprouting out of the cell in some confers certain unique phenotypic bacteria, they are known to help characters to such bacteria, which attach the bacteria to rocks in streams make them antibiotic resistant & also and also to the host tissues. responsible for bacterial

transformation. (v) Prokaryotic cell envelope consists of three layers–outer glycocalyx, middle EAGLE EYES CELL ENVELOPE ITS MODIFICATIONS  Periplasmic Space (Analogous to  Most prokaryotic cells, particularly ) present between cell wall the bacterial cells, have a chemically and in bacteria. complex cell envelope. The cell envelope consists of a tightly bound

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three layered structure i.e., the  The cell wall determines the shape of outermost glycocalyx followed by the the cell and provides a strong cell wall and then the plasma structural support to prevent the membrane. Although each layer of bacterium from bursting or the envelope performs distinct collapsing. function, they act together as a  bodies: Reserve material in single protective unit. Bacteria can be prokaryotic cells are stored in the classified into two groups on the in the form of inclusion basis of the differences in the cell bodies. These are not bound by any envelopes and the manner in which membrane system and lie free in the they respond to the staining cytoplasm, e.g., phosphate granules, procedure developed by Gram viz., cyanophycean granules and glycogen those that take up the gram stain granules. Gas are found in (crystal violet) are Gram positive blue green and purple and green (Purple Colour) and the others that photosynthetic bacteria. do not are called Gram negative

(Red/Pink) bacteria.

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CELL STRUCTURE

Cell Boundaries Nucleus Gycocalyx Cytoplasm (PH =7.2) Cell wall Cell membrane Main area of cellular activities & various chemical reactions occur in it to keep the cell in living state

Hyaloplasm/ / Intracellular fluid. Trophoplasm/ It is a complex Substance that makes up the Cytoplasmic inclusions liquid portion of the Cytoplasm of cell

Ergastic bodies/ Non-living inclusion Cell (metabolically Active content /Deutoplasm The cytoplasm also of the cell) contain substances which are metabolically inactive) Reserve Products Double Single Non Membranous Membranous Membranous  Carbohydrates

 Nitrogenous ENDOMEMBRANE  products SYSTEM  Nucleus E.R Golgi body Mitochondria Lysome MICROBODIES Glyoxisome Sphaerosome

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Rough endoplasmic Microvilli reticulum Golgi Lysosome AN OVERVIEW OF CELL Smooth apparatus endoplasmic Plasma reticulum membrane Plasmodesmata  The onion cell which is a typical plant Nucleus Centriole Smooth Peroxiome Golgi endoplasmic apparatus reticulum Lysosome cell, has a distinct cell wall as its Nuclear envelope Nuclear envelope Plasma membrane outer boundary and just within it is Nucleolus Vacuole Middle lamella Rough Cell wall endoplasmic the cell membrane. Peroxisome Nucleus reticulum Mitochondrion Cytoplasm Cytoplasm Chloroplast Ribosomes  Cells that have membrane bound Plant cell Animal cell nuclei are called eukaryotic whereas cells that lack a membrane bound CELL WALL nucleus are prokaryotic.  A non-living rigid structure called the  In both prokaryotic and eukaryotic cell wall forms an outer covering for cells, a semi-fluid matrix called the plasma membrane of Bacteria cytoplasm occupies the volume of Fungi, Algae and Plants. the cell.  Algae have cell wall made up of  The cytoplasm is the main area of cellulose, galactans, mannans and cellular activities in both the plant minerals like calcium carbonate. and animal cells. Various chemical  In other plants it consists of reactions occur in it to keep the cell cellulose, hemicellulose, pectins and in the ‘living state’. proteins.  Besides the nucleus, the eukaryotic  Bacterial cell wall mainly composed cells have other membrane bound of Peptidoglycans (Polysaccharide + distinct structures called organelles amino acid). like the (ER),  The cell wall of Fungi are composed the golgi complex, , of Chitin and Polysaccharides. mitochondria, microbodies. The  Dinoflagellates cell wall has stiff prokaryotic cells lack such membrane cellulose plate on the outer surface bound organelles. (Plated cell wall)  Ribosomes are non-membrane bound  Cell wall of diatoms is made up of organelles found in all cells – both silica and known as FRUSTULE eukaryotic as well as prokaryotic cell. Within the cell, ribosomes are found not only in the cytoplasm but also EAGLE EYE within the two organelles – 1. Archaebacteria differ from other (in plants) and bacteria in having a different cell wall mitochondria and on rough ER. structure and this feature is  Animal cells contain another non- responsible for their survival in membrane bound called extreme condition. centriole which helps in cell division. 2. In Euglenoids instead of a cell wall, the have a protein rich layer called pellicle which makes their body flexible.

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MIDDLE LAMELLA (c) Cutin :It lies as a distinct layer on the  It is cementing layer for joining of outside of the epidermal cell wall. It two adjacent plant cells. is fatty substance that reduces the  It is composed of calcium/magnesium rate of transpiration. pectate.  Retting of fibres and softerning of fruits are due to dissolution of calcium pectate in middle lamella by “pectinase enzyme”

PRIMARY WALL  It is elastic, permeable, thin, single layered outer most wall layer of plant cell. Its diameteris 0.1–3 μ m and Differences Between Primary and Secondary Walls Cellulose, hemicellulose and pectin S. S. Primary Wall Secondary Wall contents are roughly in equal amount No. No. 1 It is single layered formed in young 1 It is three or more layered formed when in primary wall. growing cell. the cell has stopped growing.  Root hairs, parenchymatous cells & 2 Cellulose microfibrils are shorter, 2 Cellulose microfibrils are longer, closely wavy and loosely arranged. arranged, straight and parallel. meristematiccells are formed of only 3 Cellulose content is compartively low. 3 Cellulose content is compartively high. primary wall. 4 Hemicellulose is upto 50%. 4 Hemicellulose is about 25%. 5 Pits are usually absent. 5 Pits are common.  Its growth takes place by 6 It grows by intussusception. 6 It grows by accretion. intussuception (Addition of materials 7 content is 5-10%, protein is 5%. 7 Lipid is absent, protein content is 1% or less. with in the existing wall).

SECONDARY WALL PITS It lies inside the primary wall. Its diameter is  They represent unthickened areas in 3–10 μ m. Its growth takes place by Accretion the secondary walls of plant cells (deposition of materials over the surface of that occur as a depressions. existing structure). It consists of at least  A pit contains pit chamber and a pit three layers–S1, S2, S3, This wall is made up membrane. The latter is composed of of cellulose, hemicellulose & pectin. Number primary wall and middle lamella. of different materials may be deposited in Pits are two types the wall.

(a) Lignin :The deposition of lignin on the cell wall is called lignification that provides strengthening to the cell wall. (b) Suberin :It is fatty substance that makes the wall impermeable. It (a) Simple pits :It bears uniform width of reduces the transpiration rate in the pit chamber. plants. It is found in the cork and (b)Bordered pits :Its chamber is flask shaped casparian strips of endodermal cells. due to overarching of secondary wall on its The deposition of suberin is called mouth. Its pit membrane has thickening of suberisation.

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suberin called Torus. These pits are found abundantly in tracheids of gymnosperms CELL MEMBRANE (have maximum number of bordered pits)  All the living cells are covered by a and in vessels of angiosperms. thin, delicate, elastic, selectively– permeable and living boundry, which TERTIARY WALL is called as – cell membrane (by Present only in tracheids of Gymnosperms & Nageli & Kramer) or plasmalemma (By composed of cellulose & xylan. J.Q. plowe) or bio membrane or Functions of Cell wall : Cell wall not only plasma membrane. gives shape to the cell and protects the cell  The detailed structure of the from mechanical damage and infection , it membrane was studied only after the also helps in cell- to - cell interaction and advent of the electron microscope in provides barrier to undesirable the 1950s. Meanwhile, chemical macromolecules. studies on the cell membrane, especially in human red blood cells EAGLE EYES (RBCs), enabled the scientists to deduce the possible structure of 1. EXPANSIN : A special protein called plasma membrane. expansin helps in growth of cell wall  Biochemical investigation clearly by loosing the cellulose microfibril revealed that the cell membranes and addition of new cell wall possess lipid, protein and material takes place in the space. carbohydrate. The ratio of protein Thus expansin is called as "cell wall and lipid varies considerably in loosening factor". different cell types. In human beings, 2. PLASMODESMATA : These are the membrane of the erythrocyte has cytoplasmic connections between approximately 52 per cent protein and two adjacent plant cells. 40 per cent Plasmodesmata are characteristic of

multi-cellular plants and they CHEMICAL COMPOSITION maintain continuity of cytoplasm between adjacent cells. E.R. tubules Proteins Carbohydrates Lipids (Desmotubules) help to maintain 58-60% 1–2% 20–40% continuity of cytoplasm.The cell wall

and middle lamellae may be

traversed by plasmodemata.

3. EXTENSIN : This protein connects

pectin and Cellulose.

4. Cell wall material (Cellulose, STRUCTURE OF BIOMEMBRANES hemicellulose, Pectin and lignin) are (1) Sandwitch or Trilamellar model :By synthesized in plant golgi body or Davson &Danielli (1935). dictyosome.  According to this model, the plasma– 5. Material of lipid nature (cutin & membrane is made up of three layers Suberin) are synthesized in in which a bimolecular layer of lipid sphaerosome.

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is sandwitched between two single serine, phosphatidyl choline layers of proteins. (Lecithin), phosphatidyl ethanolamine  According to this model each protein (cephalin) layer is 20Å thick and bilayer of  The studies showed that the cell phospholipid is 35Å thick. Thus total membrane is composed of lipids that thickness is 75Å (PLLP – structure, are arranged in a bilayer. Also, the 75–100Å average) lipids are arranged within the  Phospholipid molecule called as membrane with the polar head amphipathic molecule due to towards the outer sides and the presence of two type of parts hydrophobic tails towards the inner (hydrophillic head and hydrophobic part.This ensures that the nonpolar tail). tail of saturated hydrocarbons is  Hydrophilic head of the phospholipid protected from the aqueous binds with protein layer by hydrogen environment. The lipid component of and ionic bonds. the membrane mainly consists of  Hydrophobic tail of phospholipid are phosphoglycerides. attached to each other by vanderwall  Phospholipid layer provides fluidity to force. plasma membrane because

Protein layer phospholipids are rich in unsaturated (20 Å)

) Polar hydrophilic which are liquid in nature. Å r 5 e head y 3 (

a

l

s

r  The Quasifluid nature of lipid enable d i a l p i u l

c

o Nonpolar e l h lateral movement of protein with in o p hydrophobic tail s m o - h o i

p the overall bilayer. This ability to

B f o Protein layer Pores (0.35 nm) (20 Å) move within the membrane is

measured as its, fluidity. (2) :By Singer &  The fluid nature of the membrance is Nicolson (1972) also important in various function  This is latest & most widely accepted like cell growth, formation of model for the structure of intercellular junction, endocytosis, cell plasmalemma. division etc.  According to fluid mosaic model  Cholesterol is also present in plasma proteins are arranged in phospholipid membrane. Cholesterol are more rigid layer as mosaic pattern. than phospholipid. So it helps in  Thus membrane is termed as "protein stability of membrane structure. icebergh in a sea of phospholipid" or "Gulab Jamun (protein) in a EAGLE EYE concenterated solution (phospholipid) Cholesterol is absent in prokaryotic of sugar". cell. Thus Hopanoids (Pentacyclic sterol) provide stability to prokaryotic (1) Phospholipids : cell membrane)  Phospholipid is the main component (2) Proteins : of cell membrane because it forms Two types of protein are present in continous structural frame of cell plasma membrane. (On the basis of membrane. Main type of ease of extraction) phospholipids are phosphatidyl (a) Integral or intrinsic protein

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 These protein are tightly binds with phospholipid. Thus, they can not  Oligosaccharides of the glycolipids & easily removed from membrane. glycoproteins on the outer surface Integral proteins are of 2 types of plasma membranes are involved Partially buried in cell to cell recognition Totally buried mechanism. Best example of cell  Some integral proteins which are recognition is fertilisation, (where totally buried through the complete & egg recognize to each thickness of membrane. These type other) and blood - Antigens. of protein are called as tunnel / Protein Transmembrane/channel protein Sugar which provide a passage for Lipid bilayer movement of water soluble material across the membrane. Integral protein (b) Peripheral or extrinsic protein

 These are superficially arranged on

outer side and can be seperate easily. Cholesterol These protein have enzymatic activity. Fluid mosalic model of plasma membrane  Spectrin are helical type of extrinsic protein founds on cytosolic face (towards cytoplasm) of membrane and attached to intrinsic protein. Spectrins are part of .

Outside the cell Glycoprotein Glycolipid (Oligosaccharides) (Oligosaccharides) Peripheral protein Pore formed by (Extrinsic) integral protein Phospholipids

Non cytosolic half of bilayer Phospholipid bilayer

Cytosolic half of bilayer

Tunnel protein Cholesterol Spectrin Peripheral protein Inside the cell Fluid-mosaic molel of membrane

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TRANSPORT THROUGH PLASMA MEMBRANE

TRANSPORT

Passive transport Active transport (Energy is not utilized) (Energy is utilized) Movement of molecules occurs from lower concentration to higher concentration with help of ATP

Diffusion Facilitated Diffusion

Diffusion is a movement of molecules Movement of molecules from from higher concentration to lower high concentration to lower concentration through a lipid bilayer concentration with the help of specific protein.

 One of the most important functions membrane to facilitate their of the plasma membrane is the transport across the membrane. transport of the molecules across it.  A few ions or molecules are The membrane is selectively transported across the membrane permeable to some molecules against their concentration gradient, present on either side of it. Many i.e., from lower to the higher molecules can move briefly across concentration. Such a transport is an the membrane without any energy dependent process, in which requirement of energy and this is ATP is utilised and is called active called the passive transport. transport, e.g., Na+/K+ Pump.  Neutral solutes may move across the membrane by the process of simple

diffusion along the concentration

gradient, i.e., from higher concentration to the lower. Water may also move across this membrane from higher to lower concentration. Movement of water by diffusion is

called osmosis.

 As the polar molecules cannot pass through the nonpolar lipid bilayer, they require a carrier protein of the

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FUNCTIONS OF PLASMA MEMBRANE 2. All cells are derived from pre-existing (i) Endocytosis cells" is the famous generalization of- (a) Pinocytosis or Cell Drinking : (A) Schultz Ingestion of liquid material by (B) Schleiden plasmalemma in the form of vesicles (C) Lamarck (Pinosome) is called pinocytosis. (D) Virchow (b) Phagocytosis or Cell eating : Ans. (D) Ingestion of solid complex materials Solution by membranes in the form of All cells are derived from pre-existing vesicles () is called cells (omnis cellula–e cellula) given Phagocytosis. by Rudolf virchow. (ii) Exocytosis/Emiocytosis/Cell vomiting : 3. Cell wall is the secretory product of- Egestion of waste materials from cell (A) Lysosomes through plasma membrane. (B) Cytoplasm (C) Plasmodesmata EAGLE EYES (D) Middle lamella 1. However phospholipid bilayer Ans. (B) has fluid property but no Solution evidence of flip flop mechanism cell- wall is the secretory product of for protein molecule (Flip Flop Cytoplasm. means exchange of molecules Educatalyzer from one monolayer with those 1. Amphipathic molecule in pasma in the monolayer on the other membrane is - side). (A) Protein 2. Rotational diffusion and lateral (B) Carbohydrates diffusion of protein and lipids is (C) Phospholipids possible in membrane. (D) All the above 3. Plasma membrane is an asymmetrical 2. Cell membrane is composed of - structure because carbohydrate is (A) Proteins and cellulose presents on outer surface and (B) Proteins and phospholipids spectrin protein is present only on (C) Proteins and carbohydrates inner surface of plasma membrane. (D) Proteins, phospholipids and some carbohydrates Examples 3. Carbohydrates which present in the 1. Which of the following is the smallest cell membrane take part in:- cell- (A) Transport of substance (A) Human nerve cells (B) Cell recognition (C) Attachment to (B) Chlamydomonas (D) Attachment to (C) Virus 4. According to Singer and Nicolson (D) PPLO which of the following are present in Ans. (D) plasma membrane Solution (A) Chitin and phospholipid (B) Phospholipid, extrinsic and Mycoplasma laidlawii (PPLO- intrinsic protein Pleuropneumonia like organisms) is (C) Carbohydrates and protein smallest cell. (D) Hemi cellulose and cellulose

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 ER divide the intracellular CELL ORGANELLES space into two distinct Metabolically active and living compartment i.e. Luminal structures of cytoplasm are called (inside ER) and extra luminal organelles. (cytoplasm) compartments.  While each of the membranous TYPES OF ENDOPLASMIC organelles is distinct in terms of its RETICULUM structure and function, many of On the basis of nature of its these are considered together as an membranes, endoplasmic reticulum endomembrane system because their is of two types. functions are coordinated. (i) RER – Rough Endoplasmic  The endomembrance system include Reticulum endoplasmic reticulum (ER), golgi (ii) SER – Smooth Endoplasmic complex, lysosomes and vacuoles. Reticulum Since the functions of the Rough E.R. Smooth E.R. mitochondria, choroplast and (Granular) (Agranular) are not coordinated 1. It bears ribosomes Ribosomes with the above components, these attached to its absent on the are not considered as part of the membranes outer surface of endomembrane system. membrane 2. It consists of It consists of ENDOPLASMIC RETICULUM cisternae and few tubules and  Electron microscopic studies of tubules vesicles eukaryotic cells reveal the presence 3. It takes part in It performs of a network of reticulum of tiny the synthesis of synthesis of tubular structures scattered in the proteins and glycogen, lipids cytoplasm that is called the enzymes Ex:- and steroids. Ex:- endoplasmic reticulum (ER) pancreas, liver, Interstitial cells, Components of E.R. Goblet cells Adipose tissue, (1) Cisternae- These are long adrenal cortex, flattened and unbranched units Muscles, arranged in stacks. Glycogen storing (2) Vesicles - These are oval liver cells membrane bound structures. 4. RER bears Ribophorins are (3) Tubules - These are irregular, ribophorin- I & absent often branched tubes bounded by ribophorin-II for membrane. Tubules may free or the attachment associated with cisternae. of ribosomes 5. It may develop It may develop from nuclear from RER. envelope

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FUNCTIONS OF E.R. fragementation and high speed centrifugation of cell. They do not (1) Mechanical support : , exist as such in the living cell. Microtubules and E.R. forms Scientist used for invitro protein synthesis study. endoskeleton of cell. (4) R.E.R. of nerve cell are called nissl's (2) Intracellular exchange : E.R. forms bodies. intracellular conducting system. Transport of materials in cytoplasm (5) Protein synthesized on ribosomes from one place to another may attached to the R.E.R are targeted for occurs through the E.R.  At some places E.R. is also connected the E.R., GB, lysosome, plasma to P.M. So E.R. can secrete the membrane and outside the cell. materials outside the cell. (6) Free Ribosomes create proteins that (3) Rough E.R. : Provides site for the protein synthesis, because rough E.R., are released directly into the has ribosomes on its surface. cytoplsam for use by the cell. (4) Lipid Synthesis : Lipids (cholesterol & phospholipids) synthesized by the GOLGI COMPLEX agranular portion of E.R. (Smooth Camillo Golgi (1898) first observed densely stained reticular structure E.R.). The major lipids synthesized by near the nucleus. These were later S.E.R. are phospholipids and named Gogi bodies after him. cholesterol. Golgi body also named as  Golgi body (5) Cellular metabolism: The membranes  Dalton complex of the reticulum provides an  Golgi complex increased surface for metabolic  Lipochondria ( rich in lipids) activities within the cytoplasm.  Baker's body  Idiosome (6) Detoxification : Smooth ER concerned with detoxification of drugs,  Dictyosome (plant golgi body) pollutants and steroids.  The cytoplasm surrounding Golgi body have fewer or no other  Cytochrome P450 in E.R. act as enzyme which function in detoxification of organelles. It is called Golgi ground drugs and other toxins substance or zone of exclusion. STRUCTURE EAGLES EYES Golgi complex is made up of three (1) Sarcoplasmic Reticulum (S.R.): These parts – smooth S.E.R. occurs in skeletal and (1) Cisternae : These are flat disc cardiac muscles. S.R. Stores Ca+2 shaped, sacs like structure. Many and energy rich compounds required cisternae are arranged in a stack for muscle contraction. (parallel to each other). Diameter 0.5 μm to 1.0 μm . (2) Myeloid Bodies :– Myeloid bodies are the specialised  Varied number of cisternae are smooth E.R. which found in present in Golgi complex. pigmented epithelial cells of the  Golgi body show definite polarity. retina. Myeloid body is light sensitive  Convex surface of cisternae which is structure and may be involved in towards the nucleus is called cis face pigment migration. or forming face. (3) - These are pieces of E.R. with associated ribosomal particles. These can be obtained by

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 Concave surface of cisternae which is towards the maturing face. This towards the membrane is called explains, why the Transface or maturing face. remains in close association with the (2) Tubules : These are branched and endoplasmic reticulum. A number of irregular tube like structures proteins synthesised by ribosomes on associated with cisternae. the endoplasmic reticulum are (3) Vesicles : Spherical structures arise modified in the cisternae of the golgi by budding from tubules. Vesicles are apparatus before they are released filled with secretory materials. from its trans face. Golgi apparatus is the important site of formation of

Discharged vesicles Trans or Maturing face Cisternae glycoproteins and glycolipids.

Cisternae  All the macromolecules which are to be sent outside the cell, move through the golgi body. So golgi body

Vesicles Fusing with cis face is termed as “Director of Tubules Transition vesicles Cis or Forming face macromolecular traffic in cell” or Golgi Apparatus middle men of cell. Golgi apparatus (2) Cell plate formation(Phragmoplast) FUNCTIONS OF GOLGI BODY during cell formation. (3) Formation of during (1) Packaging and Secretion : Chief spermiogenesis. function of golgi body is secretion (4) Formation of Lysosome It is collective (export) of macromolecules. function of golgi body and E.R. Secretion involve three steps : (5) Synthesis of cell wall Material (a) Golgi body recieves the materials (Polysaccharide synthesis) from E.R. through it's cis face. (6) Vitelline membrane of egg is secreted (b) These materials are chemically by golgi body. modified by golgi body. For e.g. ROUTE OF THE SECRETORY glycosylation of proteins and PRODUCT glycosidation of lipids takes E.R.  transport vesicles  Cis region of GB place in golgi body and it yields  Trans region of GB  secretory vesicle  glycoprotiens and glycolipids. Plasma membrane. (c) After chemical modifications

materials are packed in vesicles. LYSOSOME These vesicles are pinched off  These are membrane bound vesicular from trans face of golgi body and structures formed by the process of discharged outside the cell. packaging in the golgi apparatus. The The golgi apparatus principally isolated lysosomal vesicles have been performs the function of packaging found to be very rich in almost all materials, to be delivered either to types of hydrolytic enzymes the intra-cellular targets or secreted (hydrolases – lipases, proteases, outside the cell. Materials to be carbohydrases) optimally active at packaged in the form of vesicles the acidic pH (pH 5). These enzymes from the ER fuse with the cis face of are capable of digesting the golgi apparatus and move

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carbohydrates, proteins, lipids and TYPES OF LYSOSOMES nucleic acids. Lysosomes show pleomorphism and  With the exception of mammalian are of four types. RBC they were reported from all (i) Primary lysosomes : These are newly cells. synthesized lysosomes from Golgi  In plant cells large central vacuole complex by GERL system. They functions as Lysosome. So in higher contain inactive enzymes. plants lysosomes are less frequent. (ii) Secondary lysosomes But number of lysosomes is high in (hetorophagosomes or fungi (Example Neurospora) phagolysosomes) : It is formed by the  Lysosomes are filled with 50 union of primary lysosome with food different type of digestive enzymes vacuole (Phagosome). termed as Acid hydrolases . (iii) Tertiary lysosomes (residual bodies or  These acid hydrolases function in telolysosomes) : After digestion the acidic medium (pH 5). Membrane of products are lysosome has an H+ pump absorbed in to the cytoplasm. The mechanism which produce acidic pH undigested remains are left in the in lumen of lysosome. lysosome. It is called . This moves to the surface and throws the contents by exocytosis. (iv) Autophagic Lysosomes or Cytolysosomes or autophagosomes: Lysosomes containing cell organelles to be digested are known as Autophagosomes. FUNCTIONS  Lysosomes are highly polymorphic (1) Intracellular digestion: cell organelle. Because during (a) Heterophagy: This is digestion of functioning, lysosomes have different foreign materials received in cell by morphological and physiological phagocytosis and pinocytosis. states. (b) : Digestion of old or dead cell organelles. Autophagy also takes place during starvation of cell. (2) Crinophagy: Excessive secretory granules of hormone in endocrine gland may be digested by lysosomes. This event is called crinophagy. Thyroglobulin stores in thyroid gland with its follicles and after crinophagy by proteases it produces thyroxine.  Cellular digestion (Autolysis) : Types of lysosomes and their functions Sometimes all lysosomes of a cell burst to dissolve the cell completely

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(so Lysosome called as suicidal bags  The non living content of vacuoles is of cell). Old cells are removed by known as cell sap which is rich in K+ autolysis. Unwanted organs of and acetic acid. embryo are destroyed by autolysis  In Amoeba the contractile vacuole is Cathepsin of lysosome digests the important for excretion. In many tail of tadpole of frog during cells, as in protists, food vacuoles are metamorphosis. formed by engulfing the food particles.

EAGLES EYES EAGLES EYES  Membrane stabilizers are substances, which stabilize the lysosome  Gas vacuoles (Pseudovacuoles): These membrane and stop its rupture, thus are found in some like prevents autolysis. e.g. cholesterol, blue grean algae where they perform chloroquine, cortisone etc. buoyancy regulation and they also  Membrane labilizers are substances protect the cell from UV radiation. which make the lysosome membrane  Food vacuoles: These vacuoles fragile and increase the chance of contain digestive enzymes. autolysis e.g. Progesterone,

testosterone, Vitamin A, D, E, K, U.V. Example radiations, bile salts etc. 1. In which of the following cells the  Biogenesis of Lysosome Lyosomes endoplasmic reticulum is absent- originates from G E R L - (Golgi (A) Kidney cells associated Endoplasmic Reticulum (B) Liver cells from which Lysosomes arise). (C) Mammalian mature erythrocytes VACUOLES (D) Mammalian eye cells  The vacuole is the membrane-bound Ans. (c) space found in the cytoplasm. It Solution contains water, sap, excretory Mature mammalian erythrocyte product and other materials not (R.B.C.) lacks cell organelles. useful for the cell. 2. Surface of Golgi cisternae towards  The vacuole is bound by a single nucleus is ………….. face and towards membrane called tonoplast. In plant plasma membrane is …… face. cells the vacuoles can occupy up to (A) trans, cis 90 per cent of the volume of the cell. (B) maturing, forming  In plants, the tonoplast facilitates the (C) maturing, trans transport of a number of ions and (D) cis, maturing other materials against concentration Ans. (D) gradients into the vacuole, hence Solution their concentration is significantly The Golgi cisternae are concentrically higher in the vacuole than in the arranged near the nucleus with cytoplasm. distinct convex cis or forming face and concave or trans or the maturing face.

16

3. Which of the following statement is MITOCHONDRIA not correct for the vacuoles?  Power house of cell or ATP-mill in cell (A) Contractile vacuoles are helpful in  Cell within cell excretion  Cell furanaces or storage batteries (B) Sap vacuole is bound by a single  Most busy and active organelle in cell membrane  Semi autonomous cell organelle. (C) Food vacuoles are formed by  Kolliker (1880) first observed engulfing the food particles mitochondria as cytoplasmic granules (D) Tonoplast facilitates the in striped muscles of insects. transport of ions against eh  Term 'Mitochondria, was given by concentration gradient into the C.Benda.Mitochondria is stained by cytoplasm janus green B Diameter 0.2 – 1.0 m Ans. (D) (average 0.5 m) Solution Length 1.0 – 4.1 m Tonoplast facilitate the transport of ions against the concentration SHAPE & SIZE gradient into the cell sap. Saucer and oval are two common shapes of mitochondria. Educatalyzwer NUMBER 1. ER divides the intracellular space into S.No Name of Number of two distinct compartments, luminal organism Mitochondria ………… and extra luminal ……… 1. Chlorella 1 (minimum) compartments. 2. Microsterias 1 (A) Cytoplasm, inside ER 3. Human sperm 25 (B) Inside ER, cytoplasm 4. Kidney cells 300-400 (C) Nucleus, cytoplasm 5. Liver cells 500-1000 (D) Inside ER, nucleus 6. Chaos chaos 50000 2. Chemical modification of substance like (Giant amoeba) glycosidation of protein and lipid occur 7. 500000 (maximum) in -

(A) Endoplasmic reticulum STRUCTURE OF MITOCHNDRIA (B) Golgi body Mitochondria is double membraned cell (C) Lysosome organelle. Each membrane is separated (D) Ribosome bybroad space that is called 3. Cell organelle rich in hydrolases perimitochondrial space (Outer chamber). enzyme is :- Inner membrane is folded to form cristae (A) Mitochondria that increase surface area. Shape of cristae (B) Peroxisomes is finger like in plants, plate like in (C) fungi,vesicular in Euglena. Outer surface of (D) Lysosomes inner membrane is called C- face whereas 4. Which of the following is the site of inner surface called M-face. lipid synthesis - (A) Rough ER (B) Smooth ER (C) Golgi bodies (D) Ribosome

17

1. Origin: They have originated from the symbiosis of a prokaryotic organism (aerobic bacteria) with a host cell that was anaerobic and derived its energy only from glycolysis (Endosymbiotic hypothesis).

2. Mitochondria of mammals have 55s

ribosomes. Circular mt. Inner mitochondria DNA (G.C. Rich) Cristae Outer mitochondrial F 1particle 3. Mitochondria are rich in Manganese Matrix Ribosome (70s) (inner chamber) (Mn). Perimitochondrial space (outer chamber) 4. If outer membrane of mitochondria is

removed then it is called as

mitoplast. Diagrammatic view of the internal structure of a mitochondrion/chondriosome

The inner membrane and cristae bear FUNCTIONS OF MITOCHONDRIA electron transport chain and tennis racket (i) Most of the ATP are produced by like particles called Oxysomes or Elementary mitochondria during respiration. particles. or F0 –F1 particles or ETP (Electron These ATP are required for transport particles) or ATPase particles or performing various metabolic Fernandez and Moran particles. The latter 4 5 activities. Thus mitochondria is called are 10 –10 in number. F0–F1 particles power house of cell. extracted by Racker hence they are also (ii) The gene for male sterility in maize called Racker’s particles. These are plants is found in mt DNA. thus it considered as functional unit of helps in cytoplasmic inheritance. mitochondria and they are the site of (iii) Enzymes of krebs cycle, fattly acids oxidative phophorylation. Head part of synthesis, amino acids synthesis are Oxysomes contains ATPase (ATP synthase) found in matrix. enzymes for oxidative phophorylation. (iv) Heme protein required for

haemoglobin, cytochrome and

myoglobin is synthesized in

mitochondria.

(v) Mitochondria help in Vitellogenesis in

oocytes.

PLASTIDS

Plastids are found in all plant cells and in Mitochondrial matrix is found in inner euglenoides. These are easily observed under chamber. The former contains double the microscope as they are large. They bear stranded naked, circular, DNA (mt-DNA that some specific pigments, thus imparting is rich in G–C ratio), 70S ribosomes, RNA (5- specific colours to the plants. Based on the 7%) hence mitochondria considered as semi presence or absence type of pigments autonomous cell organelles. plastids can be classified into, ,

and chloroplasts. EAGLE EYES

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LEUCOPLASTS Plant Shape of chloroplast 1. Leucoplasts : Colourless, Largest Chlamydomonas Cup shaped plastids. They classified on the basis of Ulothrix Girdle shaped stored material Spiorgyra Spiral (Ribbon like) Zygnaema Stellate (a) : They store Oedogonium Reticulate carbohydrates in the form of Higher plants Discodial or oval starch. (b) Aleuroplasts or : STRUCTURE OF CHLOROPLAST They store proteins. (c) Elaioplasts : They store oil or fats. ds-Circular DNA Outer membrane Quantasomes Inner membrane CHROMOPLASTS (230 pig. mol.) Stroma or matrix

2. Chromoplasts : In chromoplasts fat Granum thylakoid Granum Plastoglobuli soluble carotenoid pigments like Loculus 8 8 8 (Fat droplets) (Lumen of thylakoid) 70s Ribosomes Fret channel or Rubisco (Most abundant enz.) carotene, xanthophylls and others are stroma thylakoid RUBP / carboxy dismutase present. This gives yellow, orange or Chloroplast red colour to the part of the plant. Chromoplasts occurs mainly in pericarp and petals. Red colour of STRUCTURE OF CHLOROPLAST chillies and tomatoes are due to the Each chloroplast contains three parts red pigment "Lycopene" of (i) Envelope chromoplasts. (ii) Stroma  Chromoplasts also occurs in petals but (iii) Lamellar system colour of petals are mainly due to water soluble pigments occur in cell (i) Envelope sap. e.g. Anthocyanin (Blue or violet or It contains two lipoprotein unit red pigment), Anthochlor (yellow membranes. Broad space lies pigment). between these two membranes. It is called periplastidial space.Outer 3. CHLOROPLAST membranes freely permeable due to NUMBER, SHAPE & SIZE OF presence of porin proteins and CHLOROPLASTS whereas inner membrane is  Majority of the chloroplasts of the selectively permeable. green plants are found in the

mesophyll cells of the leaves. (ii) Stroma  Number varies from 1 per cell of the It is highly proteinaceous. It has Chlamydomonas a green alga to 20- double stranded circular DNA that is 40 per cell in the mesophyll. rich in G - C ratio called cp-DNA or  These are lens-shaped, oval, plastidome. Other components are spherical, discoid, or even ribbon RNA (2–3%), plastoglobules (fat shaped. globules), 70s ribosomes, proteins  Length and width are also variable. (50–60%), lipids (25–30%), Length = 5-10 m chlorophyll (5–10%), carotenoids (1– Width = 2-4 m 2%), minerals (Fe, Cu, Mg, Mn, Zn, Co)

19

and enzymes of dark reaction of (2) From Division of pre-existing photosynthesis. Rubisco is the most plastids. abundant enzyme on the earth. It ORIGIN : Endosymbiotic origin by a forms 16% protein of the chloroplast. Cyanobacterium

FUNCTIONS (1) Photosynthesis : The chloroplasts trap the light energy of sun and Outer membrane transform it into the chemical energy Inner membrane in the form glucose. Granum (2) Balancing of O2 & CO2 in nature. Thylakoid (3) Chloroplasts impart in cytoplasmic Stroma lamella inheritance. (4) Chloroplasts impart the pleasing Stroma greenary to the earth. Sectional view of chloroplast (5) Chloroplasts store vitamin K, E, (iii) Lamellar system Rubisco protein and Fe etc. It is composed of double membrane bounded tubular sacs called EAGLE EYE thylakoids or baggy trousers.  All types of plastids have common Thylakoids are structural units of origin from proplastids, sac like non- chloroplast. These (2–100) thylakoids lamellar structures. are stacked to form granum. Each  Different types of plastids may chloroplast has 40–60 grana. The transform from one form to another. latter is absent in the chloroplasts of Because genetic meteral is similar. algae and bundle sheath chloroplasts But chromoplasts never transform to of C4 plants. These chloroplasts are chloroplasts. called Agranal chloroplasts.Two grana  : In the absence of light are inter connected by long tube these plastids occur. structure called fret lamellae (stroma Examples lamellae). 1. Aerobic respiration is performed by- Inner membrane of thylakoid (A) Iysosomes contains Quantasomes or (B) Chloroplast photosynthetic functional units. Each (C) Mitochondria of them consists of 230 chlorophyll (D) Glyoxysomes molecules (160 chl a + 70 chl b) and Ans. (C) about 50 carotenoid molecules. Solution Chloroplast is considered as semi Mitochondria is the site of aerobic autonomous cell organelle due to respiration. presence of DNA , RNA, 70s ribosomes 2. Small particles present on inner and proteins synthesis systems. mitochondrial membrane are called-

BIOGENESIS (A) Cristae (B) Ergatosomes (1) From Proplastid (C) Elementary particles

20

(D) Quantasome (C) Mitochondria have a folded inner Ans. (C) membrane. Solution (D) A contractile protein capable of Inner mitochondrial membrane folds utilizing ATP is obtained into finger like projections to frommitochondria. increase surface area for the 3. Semi autonomous cell organelles of

attachment of F0-F1 particles/ cell are – oxysome/elementary particles and (A) Nucleus and chloroplast known as cristae. (B) Chloroplast and mitochondria 3. Which of the following plastids store (C) Vacuoles and golgi complex Fat? (D) Ribosome and lysosome (A) 4. Granum and stroma lamellae are the (B) Elaioplast parts of :– (C) Aleuroplast (A) Mitochondria (D) (B) Chloroplast Ans. (B) (C) Endoplasmic reticulum Solution (D) Vacuoles Plastids are of three types– , chromoplast and RIBOSOMES (ENGINE OF CELL) chloroplast. Leucoplast which  Ribosomes are the granular store fats and oil known as structures first observed under the Elaioplast. electron microscope as dense

particles by George Palade (1953). Educatalyzer 1. Mitochondria and Chloroplasts are They are composed of ribonucleic similar in having acid (RNA) and proteins and are not (A) two membranes surrounded by any membrane. (B) Cristae (C) Thylakoids  Except mammalian RBC all living (D) Ribosomes cells have ribosomes (Both (A) a, c, and d prokaryotes & Eukaryotes) (B) a, b and d (C) a and d  Ribosomes are smallest cell (D) a, c, d and e organelles Ribosomes are organelle 2. Which of the following observations without membranes. most strongly support the view that mitochondria have elctron transport  Ribosomes are also called as system/enzymes– ‘‘Organelle with in an organelle’’ & (A) Mitochondria have a property to "Protein factory of cell". concentrate in cells which TYPES OF RIBOSOMES formlocomotory structures. (1) Eukaryotic ribosomes: 80s Occur in (B) Disruption of mitochondria yields cytoplasm of eukaryotic cells. membrane fragments which are (2) Prokaryotic ribosomes: 70s Occur in able to synthesize ATP. cytoplasm and associated with

21

plasma membrane of prokaryotic  At the time of protein synthesis, cell. several ribosomes become attached  70s ribosome also present in to m-RNA with the help of smaller mitochondria and chloroplast of subunits. This structure is called eukaryotes. (55 S ribosome present in polyribosome or polysome or mitochondria of mammals) Ergosome. Ribosomes move along the  S= Svedberg unit or Sedimentation m-RNA like beads on a string, during rate. It indirectly is a measure of protein synthesis. density and size.  Each ribosome composed of two subunits i.e. larger and smaller subunits. 80s = 60s + 40s 70s = 50s + 30s  Magnesium ion is essential for the binding the ribosome sub units.  Mg+2form ionic bond with phosphate groups of r–RNA of two subunits. Three sites are found on larger sub units :  Minimum 0.001 M Mg+2concentration (i) E-site  exit site for empty t-RNA is required for structural formation of (ii) A- site  Acceptor site for aminoacyl ribosomes. t-RNA  +2 If Mg concentration increased 10 (iii) P-site site for growing polypeptide times then ribosome dimer are chain formed.

Chemical Composition of Ribosomes : 70s – 60% rRNA + 40% proteins EAGLE EYE 80s – 40% rRNA + 60% proteins 1. Larger subunit contains peptidyl 60s – rRNA 28s, 5.8s, 5s transferase enzyme (23S rRNA) which 40s – rRNA 18s helps in the formation of peptide 50s – rRNA 23s,5s bond during protein synthesis. This is 30s – rRNA 16s an example of Ribozyme. 2. After synthesis on ribosome, protein 33 proteins 21 proteins 40S Subunit are transported in cytoplasm and

h 30S Subunit t h t g g n

n 30S Subunit e e

L organelles .

L

Å Å 0

0 60S Subunit 9 0

2 50S Subunit 3 3. The proper folding and transport of 45 proteins 31 proteins Central proteins is assisted by specific 210 Å Width Stalk 200-240 Å Width 70S Ribosome 80S Ribosome proteins called Chaperons 70S and 80S Ribosome

CYTOSKELETON

22

 An elaborate network of filamentous (a) Shaft or ciliary part : It is projecting proteinaceous structures present in hair like part of ciliary appartus. the cytoplasm is collectively referred is composed of 11 to as the cytoskeleton. The microtubules (9 doublet + 2 singlet) cytoskeleton in a cell are involved in  The electron microscopic study of a many functions such as mechanical cilium or the flagellum show that support, motility, maintenance of the they are covered with plasma shape of the cell. membrane. Their core called the , possesses a number of Cytoskeleton element are of three microtubules running parallel to the types long axis. The axoneme usually has (i) Microfilament nine doublets of radially arranged (ii) peripheral microtubules, and a pair of (iii) Microtubules centrally located microtubules. Such

an arrangement of axonemal MICROFILAMENT microtubules is referred to as the  They are composed of contractile 9+2 array. (9 double + 2 singlet) protien Actin, which concern with  Arms of A tubules consist of an muscle contraction. enzymatic protein dynein similar to MICROTUBULES myosin of muscle cells. Dynein have  Microtubules are composed of ability of hydrolysis of ATP & liberates contractile protien, Tubulin. During energy for ciliary or flagellar cell division these microtubules form movement. spindle fibers.  The central tubules are connected by bridges and is also enclosed by a CILIA AND FLAGELLA central sheath, which is connected to  Cilia (sing.: cilium) and flagella (sing.: one of the tubules of each peripheral flagellum) are hair-like outgrowths of doublets by . Thus there the cell membrane. Cilia are small are nine radial spokes. structures which work like oars,  The peripheral doublets are also causing the movement of either the interconnected by linkers (A-B cell or the surrounding fluid. Flagella linker). Both the cilium & flgellum are comparatively longer and emerge from centriole-like structure responsible for cell movement. The called the basal bodies. prokaryotic bacteria also possess

flagella but these are structurally Inner Inner Dynein arms Bridge (AT Pase activity) different from that of the eukaryotic B A Peripheral microtubules flagella. (doublets)  Cilia & Flagella are mechanical, hair A B Interdoublet bridge like cellular appendages and (B-A linker) A locomotory structure. Flagellar(Naked/smooth) Central sheath Whiplash apparatus is consist of following Central microtubule Radial spoke () Parts. Plasma membrane Types of flagella Diagrammatic representation of internal structure of Cilia or Flagella

23

(b) Kinetosome or basal or manner (Non Blepheroplast or Basal body : It is independently coordinated membraneless structure, lies manner) immediately below the plasma 4. They take part 4. Flagella membrane. Basal body exhibit cart in locomotion, involved wheel structure similar to centriole. attachment, only in (9 triplet fibriles connected to a feeding and locomotion. central hub in basal body). sensation.

(c) Rootlet or Rhizoplast : This is a EAGLE EYES conical bundle of protein fibers 1. Prokaryotic and Eukaryotic flagella are made up of flagellin and tubulin which arises from basal body to protein respectively. different directions. Rootlet have 2. Prokaryotic flagella do not show 9 + 2 dark bands composed of ATPase. arrangement of microtubules. 3. Cilia or flagella are absent in Red TYPES OF FLAGELLA algae, Blue green algae or (1) Whiplash – When the laterel hair . like structures absent. (2) Tinsel – When the flagella bears & lateral hairs like structure  Centrosome was discovered by (flimmers) Benden. Boveri named as centrosome. Cilia and Flagella are similar Centrosome is absent in almost all in structure but some plant cell. differences may observed  Two centrioles (diplosome) located just outside the nucleus and lie at right angle (90°) to each other. Flimmer Cytoplasm which surrounds centrioles called as " Centrosphere". Centrioles and centrosphere collectively called centrosome or Microcentrum. Each centriole is surrounded by amorphous (Naked/smooth) Tinsel pericentriolar mass, which is called Whiplash as massules or crown or satellite.  Centrioles are membraneless Cilia Flagella elongated structure which exhibit 1. The cilia are 1. Flagella are cart wheel structure (Just like Basal small in size long (up to body of cilia). Basal body is also a (5–10m) 150 m) type of centriole. 2. Number of 2. Few in  Centrioles are absent in higher cilia per cell is number plants. very large.  Each centriole is composed of 9 3. Cilia beat in a 3. Flagella peripheral triple fibrils of coordinated beats

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microtubules but in the central part  Proximal centriole of sperm stimulate these are absent. Thus centribole has cleavage in fertilized egg after 9 + 0 arrangement of tubules. fertilization.

EAGLE EYES

1. Formation of new centriole starts in S-phase but completes in G2-Phase of Interphase.

 Each peripheral triplet fibril is MICROBODIES consists of three subfibrils–C,B, A These are membrane bounded spherical from outside towards innerside. A is bodies filled with enzymes are called as spherical or tubular shaped whereas ‘‘Micro–Bodies’’. B & C are C–shaped. A consists of 13 On the basis of functions microbodies are of protofilaments. following types – 1. Sphaerosomes  A linker connects two peripheral  Sphaerosomes occur only in plant triplet fibrils in such a way that A subfibril of a peripheral triplet fibril is cells. They are major site of lipid storage and synthesis in plants. connected with C sub fibril of  Sphaerosomes also have lysosome adjacent peripheral triplet fibril. This linker is called C–A linker. like activity so they also termed as plant lysosomes.  In the central part a proteinacious 2. Peroxisomes or Uricosomes Hub is present.Nine radial spokes  arise from Hub. The tip of each spoke In animal cells peroxisomes concerned with peroxide (H2O2) has a thickening ‘X’ before metabolism. Catalase degrade the attachment on ‘A’ subfibril of a periphral triplet fibril. ‘Y’ thickening H2O2 into water and oxygen.  In plants, peroxisomes concerned connects two ‘X’ thickenings the with photorespiration (glycolate former is also connect at C–A linker by a connective. pathway).  Peroxisomes involved in -oxidation

of fatty acids. FUNCTION OF CENTRIOLE 3. Glyoxysomes  The main function of centriole is  Occurs in oil containing seeds, yeast locomotion and the role of centriole cells, guard cells etc. in cell division is secondary function.  Glyoxysomes occurs only in plants  Centrioles take parts in synthesis of especially in fatty seeds (castor Basal bodies, cilia, flagella, spindle seed, ground nut seed etc.). poles.  Distal centriole of sperm synthesizes EAGLE EYES Axial filament of sperm.  Glyoxysomes are considered as a highly specialised peroxisomes. Glyoxylate acid cycle takes place in

25

glyoxysomes. This cycle convert fats (C) Several ribosomes attached to a into carbohydrats. single mRNA (D) Many ribosomes attached to a

strand of endoplasmic reticulum  Glyoxylate cycle is modified TCA 2. Conversion of H2O2 into H2O and O2 cycle. occurs in ……… by the enzyme………

(A) , Catalase Example (B) Peroxisome, Urease 1. Arrangement of microtubules in (C) Sphaerosome, Lipase centriole is- (D) Uricosome, Catalase (A) 9 + 2 3. An elaborate network of filamentous...... (B) 2 + 9 structure present in the cytoplasm is collectively referred to as the ...... (C) 11 + 0 (A) Cytoskeleton, proteinaceous (D) 9 + 0 (B) Proteinaceous, Cytoskeleton Ans. (D) (C) Lipoidal, Mitochondria Solution (D) Lipoidal, plasma membrane Centriole (membrane less cell 4. In which of the following tubulin organelle) show 9+0 arrangement of protein is not present? microtubules. (A) Plasma membrane (B) Cilia 2. The Ribosomes are made up of (C) Flagella (A) DNA + Protein (D) Microtubules (B) RNA + Protein NUCLEUS (C) DNA + RNA

(D) None of these INTRODUCTION Ans. (B)  Nucleus as a cell organelle was first Solution described by Robert Brown as early as Ribosomes (membrane less cell 1831. Later the material of the organelle) are made up of rRNA nucleus stained by the basic dyes +proteins (Ribnucleoprotein particles) (Acetocarmine) was given the name 3. 70s type of ribosomes found in :- chromatin by Flemming. (A) Prokaryotic cells  "Nucleus is double membrane bound (B) Prokaryotic cells, chloroplasts and dense protoplasmic body, which mitochondria controls all cellular metabolism and (C) Mitochondria encloses the genetic information of (D) Nucleus, mitochondria cell". Ans. (B)  Nucleus is consider as controller or Solution director of cell. Importance of Ribosomes are made up of rRNA & protein and are of two types–70 and nucleus in control of heredity, growth 80s. 70s ribosomes are found in and metabolism was experimentally prokaryotic cell, mitochondria and proved by Hammerling. (Experiment plastids. was on Acetabulariaa single cell Educatalyzer largest alga). 1. Polysome is formed by  If the nucleus of a cell is, (A) A ribosome with several subunits experimentally removed, then (B) Ribosomes attached to each other unicellular organism will die after in a linear arrangement

26

some time. Thus nucleus is very important.  Strasburgar stated that "Nucleus arises from divison of pre-existing nucleus only. The study of nucleus is (i) NUCLEAR MEMBRANE known as Karyology. Electron microscopy has revealed  Generally eukaryotic cell contain at that the nuclear envelope, which least one nucleus but nucleus is consists of two parallel membranes absents in mature phloem sieve tube with a space between (10 to 50 nm) elements and mature RBCs of called the perinuclear space. mammals (exceptionaly nucleus is  These membrane forms a barrier present in RBCs of camel & lamma). between the materials present inside the nucleus and that of the The size of Nucleus is 5–25 cytoplasm. The size of the nucleus depends on  The outer membrane usually remains the volume of cell, amount of DNA continuous with the endoplasmic protein and metabolic activity of cell. reticulum and also bears ribosomes In a cell there is a definite nucleo on it. At a number of places the cytoplasmicm ratio (given by Hertwig). nuclear envelope is interrupted by Nucleocytoplasmic minute pores, which are formed by (Vn ) the fusion of its two membranes. index =  These nuclear pores are the passages (Vc ) (V n ) through which movement of RNA and Vn = Volume of nucleus protein molecules takes place in both Vc = Volume of cell directions between the nucleus and

the cytoplasm.  Each nuclear pore is guarded by a octagonal discoid structure of nucleoplasmin protein this structure is called as annulus or Bleb. (Annulus + Pore = Nuclear Pore complex). STRUCTURE OF NUCLEUS  The inner side of inner nuclear membrane is lined by nuclear lamina. Interphase nucleus : Nucleus of cell This structure is formed by filaments when it is not dividing . of lamin protein. (i) Nuclear membrane or nuclear  Pore complex provides the main envelope or karyotheca. channel, between nucleoplsm and (ii) Nuclear matrix / Nucleoplasm / cytoplam, while nucleoplasmin Karyolymph / Karyolasm. regulates nucleocytoplasmic traffic. (iii) Nucleolus / little nucleus / Ribosome (ii) NUCLEOPLASM OR KARYOLYMPH  It is jelly like fluid, Its pH is 7·4 ± 0·2 and it is reservoir of number of chemicals like nucleotides,

27

nucleosides, ATPs, proteins & euchromatin lies at central part of nucleus. enzymes of RNA & DNA polymerases, (b) Heterochromatin : This is dark endonucleases, minerals, (Ca++, stained, thick and condensed part of chromatin this part has more histone Mg++) etc. and less acidic protein.  Nucleoplasm contain high Heterochromatin is genetically less concentration of Nucleotides in the active chromatin. Heterochromatin occurs near nuclear membrane. form of triphosphate. (ATP, GTP, TTP, Difference between Euchromatin and CTP, UTP) Heterochromatin.  Chromatin net and nucleolus are

embedded in nucleoplasm. Eu- Hetero- EAGLE EYES chromatin chromatin Nucleoplasm provides site for process of (i) Consist of (i) Consist of transcription. thin, thick, extended, condensed (iii) CHROMATIN NET lightstained part of  Chromatin Tern given by Flemming part of Chromatin and  Interphase nucles has a loose and chromatin. dark stained. indistinct network of nucleoprotein (ii) Genetically (ii) Less active or fibers called chromatin, which more active inactive embeded in nucleoplasm. Chromatin chromatin chromatin. net is mainly formed of DNA and (iii) Less (iii) More histone histone protein complexes. histone protein Chromatin fibres contain genetic protein information and condensed to form (iv) Replicate in (iv) Replicate in constant number of chromosomes early s late s phase during cell division. phase  Chemically chromatin consists of DNA (31%), RNA (2-5%), Histone (iv) NUCLEOLUS protein (basic proteins) (36%) and  The nucleoplasm also contain non histone proteins (Acidic proteins) nucleous. (28%).  The nucleoli are spherical and  On the basis of relative (H2A, H2B, H3, membraneless structure so that the H4, H1) amount of arginine and lysin content of nucleous is continous with there are five type of Histone protein. the rest of the nucleoplasm. Amino acid Type of histone  It is a site for active ribosomal RNA Lysin rich H1 synthesis. Slightly lysin rich H2A, H2B  Nucleolus usually attached to Arginine rich H3, H4 chromatin (or chromosomes) at Chromatin net has two type of specific site called Nucleolar chromatins. organiser region/NOR. (a) Euchromatin : This is lightly  Number of nucleolus in a nucleus is stained and diffused part of one. Onion cell has 4, and in oocytes chromatin. Which is transcriptionally of amphibian has 2000 nucleoli. or genetically more active. Generally Human cell has 5 nucleoli.

28

 Nucleolus disappears during prophase and reappears in telophase. INTRODUCTION

 At the time of cell division the FUNCTIONS OF NUCLEOLUS chromatin material get condensed to  Ribosome formation is the chief role form chromosomes, thus of nucleolus, thus its called as chromosome is highly condensed Ribosme factory of cell, the proteins form of the chromatin. Chromosomes of ribosomes are synthesised in are not visible during interphase cytoplasm but it diffused in to stage. nucleus and reach at nucleolus. Here  First of all, chromosomes was r-RNA and ribosomal proteins are observed by Hofmeister (1818) and assembled to form ribosomes which Karl Nageli in mother cells move to cytoplasm through nuclear (PMC) of Tradescantia. pores.  Strasburger (1875) described  Larger and more numerus nucleoli are chromosome structure appeared in present in cells actively carrying out nucleus during cell division. (Credit of protein synthesis. discovery of chromosomes goes to Strasburger) FUNCTIONS OF NUCLEOLUS  Term "Chromosome" was proposed (i) Genetic information: Nucleus by Waldeyer. (Term 'Chromatin, was contains genetic information in its suggested by Flemming) chromatin (store house of genetic material) SIZE (ii) Transmission of genetic information:  Size–Chromosomes are 0.5 –30m in Nucleus takes part in transmission of length and 0.2–3m diameter. Trillium genetical information from parent plant has longest chromosome) cell to daughter cell or the one  Plants generally have larger generation to next. (iii) In cell-division: Division of nucleus is chromsomes than animals and pre-requisite to cell division. amongst plants, monocots have (iv) Control of metabolism: Nucleus bigger chromosomes than dicots. controls metabolism of cell by  During cell division, Dehydration & sending m-RNA in cytosol (Basically condensation of chromatin network biomolecule DNA controls cellular activities through directing synthesis take place as a result chromatin is of enzyme). converted into chromosomes. (v) Variations : Variation develops due to  Chromosomes can be best studied at change in genetic material of metaphase stage because size of nucleus. (Evolutionary role). chromosomes is the shortest during

metaphase (Shape of chromosome is CHROMOSOMES studied at Anaphase stage) CHROMOSOME NUMBER IN SOME ORGANISMS Plants 2n n Mucor hemelis (Fungi) 2 1 Haplopappus gracilis (Family compositae) 4 2 Pisum sativum (Pea) 14 7

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Zeamays (Maize) 20 10 Wheat (Triticum) 42 21 Ophioglossum reticulatum (Pteridophyta) 1260 630

Animals 2n n Ascaris megalocephala (Round worm) 2 1 Drosophila melanogaster (Fruit fly) 8 4 Chimpanzee/Gorilla 48 24 Homo sapiens 46 23 Aulocantha (a protozoan) 1600 800  2n = number of chromosome in (iv) Sub metacentric : When the diploid cell. n = number of centromere located near centre or chromosome in haploid cell. mid point of chromosome.  The number of chromosome is  The ratio of length of the long arm to definite for each species. For the short arm of a chromosome is example every normal human being called arm ratio. Arm ratio is has 46 chromosomes in each body maximum in acrocenteric cell. chromosome.  Gametes of all organisms contain

only one of each chromosome. The

number of chromosomes in a gamete

is called "Genome" or haploid

chromosome (Human 23) ‘‘A

complete set (n) of chromosomes (all

genes) inherited as a unit from one

parent is known as genome,,.

 A single human cell has

approximately 2.2 meter long thread STRUCTURE OF CHROMOSOME (Parts of DNA distributed among its forty six which appears in (23 pairs) chromosomes. metaphasechromosome) TYPES OF CHROMOSOMES ON THE 1. Pellicle– This isoutermost, thin BASIS OF POSITION OF proteinaceous covering or sheath of CENTROMERE chromosome. 2. Matrix – This is a liquid nongenetic (i) Telocentric : When centromere is achromatic ground substance of terminal or located at the tip of chromosome, which has different type chromosome. of enzymes, minerals, water, proteins. (ii) Acrocentric : When the centromere is 3. Chromatid – At metaphase stage each sub-terminal or located near the tip. chromosome is consist of two (iii) Metacentric : When the centromere is cylindrical structures - called located at mid of the chromosome. chromatids. Both sister chromatids are joined together by a common

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centromere. A chromosome, may have region) (13,14,15,21,22 chromosomes in single chromatid (in Anaphase or human) Telophase) or two chromatid. (as in  Secondary constriction-II is found in prophase metaphase) the chromosome number 1, 10, 13, 17 Each chromatid is consist of a single & Y chromosomes of human. long thread of DNA associated with

histone. Non histone proteins and Primary constriction (Centromere) Chromonema RNA are also present. Kinetochore Matrix (Protein dics) Second constriction II Pellicle Chromomere Telomeric DNA (Synth. by Telomerase or RNP) Secondary constriction-I NOR (r-RNA synthesis) Telomere SAT e

r Satellite (Trabent) o h

c A schematic diagrammatic representation of chromosome o t e n i k

6. Satellite - part of chromosome remains after the NOR is known as chromosomes satellite/ Trabent. Chromosome with kinetochore Chromosomes with satellite part are 4. Centromere/Kinetochore (Primary called as SAT chromosome (SAT - constriction) - Each chromosome (at Sine Acid Thymonucleinico) metaphase) is consist of two 7. Telomere - Chromosomes have chromatids. Both the chromatids of a polarity and polar ends of chromosome are joined or connected chromosomes are known as by a structure called Centromere. At Telomeres.Telomere prevents fusion this point or centromere two protein of one chromosomes to other discs are present which is called chromosome. Telomere rich in Kinetochore. Guanine base (5'-TTAGGG-3'). Enzyme  Kinetochores - constitute the actual Telomerase presents in telomere part site of attachement of spindles to of chromosome, which is a chromosomes during cell division. Ribonucleoprotein.  At the region of centromere the chromosome is comparatively EAGLE EYE narrower than remaining part of  According to Richard kathan (2003) chromosome, thus it is termed as telomeres of chromosomes becomes Primary constriction. shorter during ageing process. 5. Secondary constriction - Besides  Karyotype: is external morphology of primary constrictions, other all Chromosomes of a cell which is constriction may also occurs on specific for each species of living some chromosome, which are known organisms. Karyotype can be studied as secondary constriction. These in metaphase of . constriction are non staining and  Karyotype includes the number of found at a constant location. chromosomes, relative size, position  Secondary constriction-I is also of centromere, length of the arms, known as NOR (Nucleolar organizer secondary constrictions and banding patterns.

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 Idiogram: Diagrammatic representation of  Axis of lamp brush chromosome is Karyotype. In idiogram chromosomes are consist of DNA, while matrix is arranged in decreasing order of size. Sex consist of RNA & proteins. chromosomes are placed in last Idiogram  Lamp brush chromosome is is specific for every species. concerned with “Vitellogenesis” (Yolk formation.) SPECIAL CHROMOSOMES

POLYTENE CHROMOSOMES (SALIVARY GLAND CHROMOSOMES)  This type of chromosome was discovered by Balbiani in salivary glands of chironomous larva of dipteran insect. These are also found Example in salivary glands of drosophila. 1. Hetero-chromatin is :-  In polytene chromosomes, number of (A) Darkly stained part of chromatin chromatids are very high due to (B) Lightly stained part of cristae repeted division of chromosome (C) Lightly stained part of grana without centromeric and nuclear (D) Scattered Lobes in cytoplasm division such division is called Ans. (A) endomitosis or endoreduplication Solution [repeated replication of DNA] Large Heterochromatin is darkly stained, swellings are found on some places thick and condensed part of that are called puffs (Balbiani rings). chromatin.Heterochromatin is In puffs DNA is uncoild for rapid genetically less active. transcription of RNA and Synthesis of 2. Genome is- proteins. (A) Diploid set of chromosomes (B) Haploid set of chromosomes (C) A single chromosome (D) None of the above Ans. (B) Solution The number of chromosome in a gametes or haploid chromosome is called genome

3. The non-sticky chromosomal ends are LAMP BRUSH CHROMOSOME knwon as -  Found in oocytes of vertebrates (A) Chromatids (Amphibia) during diplotene stage of (B) Centromere cell division. These chromosomes (C) Chromomere look like lamp brush, thus called as (D) Telomere lamp brush chromosomes. Ans. (C) Solution

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Chromosome have polarity and polar (C) Basic nucleopid protein called as ends of chromosomes are knownas polyamines telomeres. Telomere prevent fusion (D) Actin of one chromosome to other 3. Who coined the term chromatin to chromosome. Telomere rich in describe the thread like material of guanine bases (5’-TTAGGG-3’) the nucleus? (A) W. Flemming Educatalyze (B) W. Roux 1. The protein nucleoplasmin occurs in - (C) E. Strasburger (A) Nuclear pore complex (D) Boveri (B) Sieve cells 4. The telomeres of eukaryotic (C) Nucleolus chromosomes consists of short (D) Heterochromatin sequence of 2. In bacterial cell DNA is extensively (A) Cytosine rich repeats looped and coiled with help of (B) Adenine rich repeats (A) Acid proteins (C) Guanine rich repeats (B) Histones (D) Thymine rich repeats

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Exercise-1 Cytoplasm, Size of Cell, Cell Wall

1. What type of material is the (D) Living and selective cytoplasm? 8. The intercellular structure separating (A) Water soluble material the walls of two adjacent cells is (B) Fat soluble material (A) Primary wall (C) Colloidal material (B) Middle lamella (D) Permeable material (C) Plasma membrane 2. Cell wall was first studied by (D) Secondary wall (A) Bonner 9. The most abundant substance of (B) Flemming middle lamella is- (C) Strasburger (A) Pectin (D) Robert Hooke (B) Suberin 3. Which of the following is the smallest (C) Cutin cell (D) Lignin (A) Virus 10. Ripening fruit becomes soft due to (B) Chlamydomonas (A) Incorporation of pectin in middle (C) PPLO lamella (D) Human nerve cells (B) Conversion of strach into sugar 4. All cell are derived from pre-existing (C) Dissolution of pectate of middle cells” is the famous generalization of lamella - (D) Jelly formation at acidic pH (A) Schultz 11. Which is the thickest wall layer (B) Virchow (A) Primary wall (C) Lamarck (B) Tertiary wall (D) Schleiden (C) Secondary wall 5. One of the following is an exception (D) Middle lamella to cell theory 12. Plasmodesmata are:- (A) Bacteria (A) Protoplasmic connections (B) Prokaryotes (B) Pores in cell membrane (C) Blue green algae (C) Pores in cell wall (D) Bacteriophage (D) 1 and 2 both 6. Small cell are metabolically active as they have CELL MEMBRANE (A) Higher surface area to volume ratio 13. Plasma membrane is : (B) higher nucleocytoplasmic ratio (A) Permeable (C) Lower nucleocytoplasmic ratio (B) Impermeable (D) both (1) & (2) (C) Selectively permeable 7. Cell wall is (D) Semipermeable (A) Dead and impermeable 14. Correct sequence of protein (P) and (B) Dead and permeable lipid (L) in cell membrane is (C) Living and impermeable (A) L-P-P-L

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(B) P-P-L-L regard, which of the following (C) P-L-L-P statements is incorrect? (D) L-P-L-P (A) Proteins in cell membranes can 15. According to fluidmosaic model travel within the lipid bilayer (proposed by Singer & Nicolson) (B) Proteins can also undergo flip- plasma membrane is composed of:- flop movements in the liplid (A) cellulose, hemicellulose bilayer (B) Phospholipid and integrated (C) Proteins can remain confined protein within certain domains of the (C) Phospholipid, extrinsic protein, membranes intrinsic protein (D) Many proteins remain completely (D) Phospholipid and hemicellulose embedded within the lipid bilayer 16. Plasma membrane is fluid structure 20. Fluid mosaic model of cell membrane due to presence of: proposes that (A) Carbohydrate (A) A lipid bilayer with embedded (B) Lipid proteins only (C) Glycoprotein (B) A lipid bilayer with proteins on (D) Polysaccharide the outer surface only 17. Cell recognition and adhesion occurs (C) A lipid bilayer coated with due to the following component of proteins on both the surfaces the plasma membrane (D) A lipid bilayer with proteins of (A) Protein two types, embedded (intrinsic) (B) Lipids and superficial (extrinsic) (C) Proteins and lipids 21. Carrier molecules facilitating (D) Glycoproteins & glycolipids transport across cell membrane are 18. Plasma membrane is asymmetric (A) Proteinaceous because (B) Fatty acids (A) Lipids present in the outer and (C) Starch inner side of the bilayer are (D) Alkaloids different 22. Plasma membrane particularly in (B) Extrinsic proteins are more animal cell is elastic due to abundant on the inner surface (A) Lipids than on the outer surface (B) Proteins (C) Oligosaccharides are attached (C) Carbohydrates only to the external surface of (D) None of these lipids and proteins of a biomembrane (D) All of these 19. According to widely accepted “fluid mosaic model” cell membranes are ENDOPLASMIC RETICULUM semi-fluid,where lipids and integral proteins can diffuse randomly. In 23. Endoplasmic reticulum often bears recent years, this model has been (A) Centrioles modified in several respects. In this (B) Lysosomes

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(C) Ribosomes 30. Myeloid bodies, sarcoplasm of (D) Plastids muscles and nissl granules are rich 24. Which organelle help in the synthesis in- of lipids (A) Fats (A) Golgi complex (B) Golgi bodies (B) RER (C) Lipids (C) SER (D) ER (D) none of these 31. The close functional relationship 25. Which of the following is associated between ER, Golgi, Lysosome are with detoxification of drugs and represent as- muscle contraction by the release and (A) GERL system uptake of Ca2+ ions (B) Vacuolar system (A) Golgi complex (C) Annulated lamellae (B) RER (D) None of the above (C) SER 32. Microsomes are related to (D) Free ribosomes (A) Endoplasmic reticulum 26. The site of detoxification reaction in (B) Spherosomes liver is (C) Lysosomes (A) SER (D) Plasmalemma (B) Free ribosomes (C) RER GOLGI COMPLEX (D) hydrophobic interaction 27. In GERL system ER is - 33. Cell organelles associated with (A) RER secretion are - (B) SER (A) Mitochondria (C) Both (1) and (2) (B) Ribosomes (D) None of these (C) Chloroplasts 28. ER is involved in all of the following (D) Golgi complex except- 34. Besides giving out secretory vesicles, (A) Production of ribosomes Golgi apparatus is also concerned (B) Synthesis of lipids with formation of (C) Synthesis of proteins (A) Grana of chloroplasts (D) Transportation of molecules to (B) Plastids the cell membrane for export. (C) Cell plates after cells division in 29. Which organelle help in the synthesis plants of lipids, cholesterol, steroids and (D) Lysosomes visual pigments in epithelial cells of 35. The Golgi complex is specialized for retina. (A) Glycosylation of lipids and (A) RER proteins (B) SER (B) Conversion of light energy into (C) Golgi bodies chemical energy (D) All of these (C) Generation of ATP (D) Intracellular digestion

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36. Which one takes part in acrosome (B) Catalse synthesis (C) Galactosidase (A) Golgi apparatus (D) Acid phosphatase (B) Lysosome 43. Which of the following organelle show (C) Nucleus polymorphism (D) Mitochondria (A) Golgi apparatus 37. The organelle that moves materials (B) lysosome out of the cell is- (C) Mitochondria (A) ER (D) Chloroplast (B) Lysosomes 44. Which types of lysosomes contribute (C) Golgi bodies to the ageing process (D) Ribosomes bound on ER (A) Primary lysosomes 38. Which organelle is located near the (B) Secondary lysosomes nucleus and contains stack of (C) Autophagic vacuoles flattened cisternae structures? (D) Residual bodies (A) Centrosome 45. Pri. lysosome + phagosome forms (B) Chloroplast (A) Residual body (C) Golgi bodies (B) Secondary lysosome (D) Centriole (C) Autophagic vacuole 39. Secretory vesicles are pinched off (D) None from _____ side of dictyosomes- 46. In plant cell lysosome is absent but a (A) Plain plant cell with lysosome exceptionally (B) Convex is- (C) Concave (A) Spirogyra (D) All sides (B) Neurospora (C) Acetabularia LYSOSOME (D) Riccia 47. Autophagic vacuoles digest. 40. Lysosomes are celled "suicide bags” (A) Cell organelles because they have (B) Solid particles of (A) Catabolic enzymes (C) Fluid droplets of pinosomes (B) Food vacuole (D) None of the above (C) Hydrolytic enzymes (D) Parasitic activity. VACUOLES 41. Most of hydrolytic enzymes of lysosomes function at- 48. Vacuole is surrounded by a single (A) Basic pH membrane called (B) Any pH (A) Plasmalemma (C) Neutral pH (B) Vacuole wall (D) Acidic pH (C) Tonoplast 42. The mitochondria serves as a marker (D) Tono membranous for cytochrome oxidase and the 49. A large and mature plant cell has Lysosomes serve for ...... (A) Many Vacuoles (A) Succinic dehydrogenase (B) A large vacuole

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(C) No vacuole (A) Chloroplasts (D) Many small vacuoles and a large (B) Vacuoles vacuole (C) Mitochondria 50. In a plant cell vacuole contains- (D) Ribosome (A) Water 58. Cytochrome oxidases are found (B) Dissolved salts (A) On outer wall of mitochondria (C) Gases (B) In the matrix of mitochondria (D) All of these (C) In the lysosomes 51. Cell sap is- (D) On cristae of mitochondria (A) Non living part of cytoplasm 59. In living cells mitochondria can be (B) Living part of cytoplasm stained with (C) Living matter of cell (A) Neutral red (D) Non living part of vacuole (B) Janus green 52. Vacuolar cell sap has pH- (C) Crystal violet (A) Alkaline and hypotonic (D) Aceto-orcein (B) Neutral and isotonic 60. Mtiochondria are not found in (C) Acidic and hypertonic (A) Liver cells (D) Equal to cytoplasm and isotonic (B) Proteins 53. Organic acid and most common (C) Mature RBCs element in sap vacuole- (D) Immature RBCs (A) Ca++, acitic acid 61. Mitochondria and chloroplast contain (B) K+, oxaloacetic acid (C) Ca++, citric acid (A) DNA (D) K+, acetic acid (B) DNA + RNA 54. Vacuoles help in- (C) DNA + RNA + ribosomes (A) Making cell light (D) Proteins (B) Storing wastes and food particles 62. Synthesis of ATP in mitochondria (C) Separating water from cytoplasm takes place (D) All of the above (A) In the matrix (B) In the intracristal space MITOCHONDRIA (C) At the cristae 55. Mitochondria are the site of (D) At the outer membrane (A) ATP formation 63. The mitochondrial DNA differs from (B) Cellular respiration the nuclear DNA in (C) Electron transport (A) Lacking association with histone (D) All of these (B) Being circular in nature 56. Which of the following structure is (C) Having higher C–G ratio present in mitochondria. (D) All of these (A) Oxysome 64. Mitochondria are absent in- (B) Polysome (A) Blue green algae (C) Dictyosome (B) W.B.C. of mammals (D) Quantasome (C) Red algae 57. Oxidative phosphorylation takes place (D) Green algae in

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65. The inner membrane of mitochondria dissimilar bears foldings called cristae these 71. Most of the biological energy is cristae supplied by mitochondria through– (A) Increase ATP supply (A) Breaking of sugars (B) Keep external substances away (B) Oxidising TCA substrate (C) Increase the thickness of wall (C) Reduction of NADP+ (D) Increase surface area (D) Breaking of Proteins 66. Oxysomes or elementary particles are 72. Inner membrane of mitochondria– centre of oxidative phosphorylation (A) Cytochrome oxidase are found in- (B) Succinic dehydrogenase (A) Inner membrane of chloroplast (C) Malic dehydrogenase (B) Outer membrane of mitochondria (D) Both (1) and (2) (C) Perimitochondrial space 73. Mitoplast is– (D) Inner membrane of mitochondria (A) Mitochondria without inner 67. Mitochondrial DNA is naked without membrane histone, double stranded and circular, (B) Mitochondria without outer discovered by Nass and Nass It is rich membrane in (C) Membraneless mitochondria (A) C–A ratio (D) Another name of mitochondria (B) A–G ratio (C) A–T ratio PLASTIDS (D) G–C ratio 68. Enzyme ATPase is found in head of 74. Which of the plastid stores protein oxysome that is called– (A) Elaioplast (A) F0 (B) Chloroplast (B) F1–F0 (C) Amyloplast (C) F1 (D) Aleuroplast (D) None of these 75. The pigment which is not found in 69. If a cell is placed under anaerobic chloroplast is- condition– (A) carotene (A) ER will disappear (B) chlorophyll (B) Mitochondria will multiply (C) xanthophyll (C) Mitochondria will disappear (D) anthocyanin (D) Mitochondria and ribosomes will 76. The most abundant protein in the multiply speedly. plant world is found in 70. Outer and inner membrane of (A) Root hairs motochondria are– (B) Mitochondria (A) Structurally similar but (C) Chloroplasts functionally different (D) Viruses (B) Functionally similar but 77. The endosymbiotic theory explains- structurally different. (A) The origin of the nucleus (C) Structurally and functionally (B) The origin of mitochondria and similar chloroplasts (D) Structurally and functionally (C) Why prokaryotic cells are

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different from eukaryotic cells (B) Ulothrix and Chara (C) Where the endomembrane (C) Chlamydomonas and Zygnaema system came (D) Vaucheria and Fritschiella 78. Chloroplasts are called semi- 85. Larger thylakoids in chloroplast are autonomous structures due to called– presence of- (A) Grana lamellae (A) RNA only (B) Stroma lamellae (B) DNA only (C) Grana (C) Both RNA and DNA (D) Loculus (D) Pigment and proteins 86. A piece of corrot and a flower is put 79. The process in which excess molecule in water separatly. The water of glycolate passes out of the becomes purple in case of carrot but chloroplast and enter in peroxisome remain colourless in flower case . It is and oxidised, is called- due to– (A) Respiration (A) In flowers, carotenoid pigments (B) Photosynthesis are fat soluble and found in (C) Photorespiration chromoplast and not come out in (D) All of the above water. 80. Which one is universal photosynthetic (B) In carrot, Anthocyoxin pigments pigment in green plants are found in cell sap which are (A) chl a water soluble. (B) chl c (C) In flowers pigments are found in (C) chl d cytoplasm while in carrot, (D) chl e pigments are localized in 81. Dimorphic chloroplasts are found is vacuoles. (A) C3 Plants (D) Both (1) and (2) are correct. (B) C4 Plants 87. In chloroplast proteinaceous granule (C) Aquatic plants surrounded by starch forms a (D) Xerophytic plants compact body called– 82. Fret channels are characteristics of– (A) Paramylum (B) Dictyosome (A) Mitochondria (C) Microsome (B) Dictyosomes (D) Pyrenoid (C) ER 88. Agranal chloroplasts are found in – (D) Chloroplast (A) Mesophyll of maize leaves 83. The complex liquid matrix of (B) Bundle sheath of mango leaves chloroplast is called– (C) Bundle sheath of sugarcane (A) Cytoplasm leaves (B) Cytosol (D) Mesophyll of pea plants (C) Hyaloplasm (D) Stroma RIBOSOME 84. Cup shaped and star shaped 89. Engine of the cell is chloroplasts are found in– (A) Ribosome (A) Spirogyra and Cladophora (B) Lysosome

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(C) Vacuole (B) Nucleus (D) Mitochondria. (C) Nucleolus 90. Ribosomes are attached to (D) Golgi body endoplasmic reticulum through 97. In ribosomes two subunits are - (A) r-RNA (A) Joins only at the time of protein (B) Hydrophobic interaction synthesis (C) t-RNA (B) Lie freely in cytoplasm (D) Ribophorins (C) Dissociates at the end of protein 91. The smallest organelles in the cell are synthesis (D) All of the above (A) Dictyosomes 98. Ergasomes are formed by- (B) Lysosomes (A) 5 ribosomes (C) Microsomes (B) More than 4 ribosomes attached (D) Ribosomes to ER 92. The larger sub-unit of 80 S ribosomes (C) more than 5 ribosomes attached contain the following RNA molecule to a mRNA (A) 23 S, 5.8 S. 5.0 S (D) Cluster of ribosomes (B) 28 S, 5.8 S. 5.0 S 99. 70 S type of ribosomes are found in- (C) 25 S, 5.8 S. 5.0 S (A) Eukaryotic cells (D) 25 S, 5.8 S. 5.0 S (B) Mitochondria 93. Protein synthesis in an animal cell (C) Prokaryotic cells occurs (D) All of these (A) Only on the ribosomes present in 100. Organelle within organelle is the cytosol (A) Ribosome (B) Only on ribosomes attached to (B) Lysosome the nuclear envelope and ER (C) Vacuole (C) On ribosomes present in the (D) Mitochondria cytoplasm as well as in CILIA & FLAGELLA& CENTRIOLES mitochondria 101. Adenosine triphosphate (ATP) powers (D) On ribosomes present in the the movement of cilia and flagella, nucleolus as wall as in cytoplasm adenosine triphosphatase activity is 94. Ribosomes are present in (A) Amphoteric (A) Nexin protein (B) Positively charged (B) Dynein protein (C) Negatively charged (C) Massule (D) None (D) Both (1) & (2) 95. Peptidyl transferase is found on- 102. Basal bodies are associated with the (A) A-site of smaller unit of ribosome development of- (B) P-site of larger unit of ribosome (A) Cilia and flagella (C) Entire ribosome (B) Cell plate (D) mRNA (C) Phragmoplast 96. Site of formation of ribosomal (D) Kinetochore precursor in cell is- 103. Cilia and flagella have- (A) Stroma (A) Dissimilar internal structure and

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are of similar size (D) Cyanobacteria. (B) Dissmilar internal structure and are of unequal size MICROBODIES (C) Similar internal structure and are 110. Glyoxylate cycle occuring in of dissimilar size glyoxysomes is a modified form of- (D) Similar internal structure and are (A) Calvin cycle of equal size (B) Glycolysis 104. 9 + 0 microtubular structure is found (C) Kreb’s cycle in- (D) Glycolate cycle (A) Centriole 111. Plant lysosomes rich in fats and (B) Basal body taking part in -oxidation of fattyacids (C) Blepharoplast are- (D) All of these (A) Lysosomes 105. Protein tubulin does not occur in- (B) microsomes (A) Flagella (C) Sphaerosomes (B) Plasma membrane (D) Glyoxysomes (C) Cilia 112. Catalase is found in- (D) Microtubule (A) Cell membrane 106. Centrosome is (B) Lomasomes (A) Cytoplasmic structure of animal (C) Mitochondria cells (D) Peroxisome (B) A nuclear structure of animal 113. From endosperm of germinating cells castor bean extruded cell organelles (C) Cytoplasmic structure of plant are- cells (A) Peroxisomes (D) Cytoplasmic structure of animal (B) Glyoxisomes cells and some lower plants (C) Transosomes 107. Centrosome is rich in (D) None (A) RNA 114. Glyoxylate cycle plays an important (B) DNA role in conversion of- (C) ATP (A) Glycerol into carbohydrate (D) Enzymes (B) Fatty acids into carbohydrates 108. Basal body could be another name of (C) Proteins into carbohydrates centriole in view of internal structure (D) Simple carbohydrates into when complex carbohydrat (A) It gives rise to spindle 115. Which of the following organelle takes (B) It divides during mitosis part in photorespiration (C) It gives basic reactions (A) Glyoxisome (D) It gives rise to cilia and flagella. (B) Peroxisome 109. Centriole and centrosome are found (C) Dictyosome in the cell of (D) ER (A) Animals NUCLEUS (B) Green plants 116. The was discovered by (C) Bacteria (A) De Duve

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(B) Robert Brown 124. Chromosomes composed of :- (C) Robert Hooke (A) DNA, RNA, Histones, Non histones (D) Virchow (B) DNA and Histones 117. Nuclear material without nuclear (C) DNA and RNA membrane is found in (D) DNA, RNA and Histones (A) Mycoplasma and green algae 125. Which part of chromosome is concern (B) Bacteria and green algae with ageing of organism and cancer. (C) Bacteria and cyanobacteria (A) Centromere (D) Cyanobacteria and red algae (B) Telomere 118. Genome is (C) Kinetochore (1) Diploid set of chromosomes (D) Satellite (2) Haploid set of chromosomes 126. The non–sticky chromosomal ends (3) A single chromosome are known as – (4) None of the above (A) Chromatids 119. A constriction on the chromosomes is (B) Centromere called (C) Chromomere (A) Centromere (D) Telomere (B) Centrosome 127. Highest arm ratio occur in which (C) Centriole chromosome :– (D) Chromomeres (A) Telocentric 120. Nucleolus takes part in the synthesis (B) Metacentric of (C) Submetacentric (A) rRNA (D) Acrocentric (B) tRNA (C) mRNA 128. The protein nucleoplasmin occurs in (D) None of these (A) Nuclear pore complex 121. The genetic material of the bacterial (B) Sieve cells cell is localised within a discrete (C) Nucleolus region, called as (D) Hetero chromatin (A) Nucleus 129. If the centromere is sub–median the (B) Nucleolus two arms are unequal then the (C) Plasmid chromosome is called as (D) (A) Metacentric 122. Nucleolus is produced from (B) Submetacentric (A) 1st constriction (C) Acrocentric (B) Nucleolar organising region of (D) Telocentric certain chromosomes (C) Nuclear envelope (D) ER 123. Nucleolar organizer is a :- (A) Primary constriction (B) Secondary constriction (C) Tertiary constriction (D) Centriole

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EXERCISE-2 1. Protein synthesis in an animal cell Permeable to all kinds of occurs [2005] molecules (A) On ribosomes presents in (B) The enzymes of the electron cytoplasm as well as in transfer chain are embedded in mitochondria the outer membrane (B) On ribosomes present in the (C) The inner membrane is highly nucleolus as well as in convoluted forming a series of cytoplasm infoldings (C) Only on ribosomes attached to (D) The outer membrane resembles the nuclear envelope and asieve endoplasmic reticulum 6. Which one of the following is not a (D) Only on the ribosomes present constituent of cell membrane? in cytosol [2007] 2. Centromere is required for [2005] (A) Phospholipids (B) Cholesterol (A) Movement of chromosomes (C) Glycolipids (D) Proline towards poles 7. Select the wrong statement from the (B) Cytoplasmic cleavage following [2007] (C) Crossing over (A)The chloroplasts are generally (D) Transcription much larger than mitochondria 3. According to widely accepted “fluid (B) Both chloroplasts and mosaic model” cell membranes are mitochondria contain an inner semifluid, where lipids and integral and an outer membrane proteins can diffuse randomly. In (c) Both chloroplasts and recent years, this model has been mitochondria have an internal modified in several respects. In this compartment, the thylakoid regard, which of the following space bounded by the thylakoid statements are incorrect [2005] membrane (A) Proteins can also undergo flip- (d) Both chloroplasts and flop mitochondria contain DNA movements in the lipid bilayer 8. Vacuole in a plant cell [2008] (B) Many proteins remain completely (A) lacks membrane and contains air embedded within the lipid bilayer (B) Lacks membrane and contains (C) Proteins in cell membranes can water and excretory substances travel within the lipid bilayer (C) is membrane-bound and contains (D) Proteins can remain confined storage proteins and lipids within certain domains of the (D) is membrane-bound and contains membranes water and excretory substances 4. The main organelle involved in 9. The two subunits of ribosome remain modification and routing of newly united at a critical ion level of synthesized proteins to their [2008] destinations is [2005] (A) magnesium (B) calcium (A) Endoplasmic Reticulum (C) copper (D) manganese (B) Lysosome 10. Cellulose is the major component of (C) Mitochondria cell walls of: [2008] (D) Chloroplast (A) Pseudomonas 5. Which of the following statements (B) Saccharomyces regarding mitochondrial membrane is (C) Pythium not correct? [2006] (D) Xanthomonas (A) The outer membrane is 11. Polysome is formed by [2008] (A) a ribosome with several subunits

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(B) ribosomes attached to each other (A) phospholipids embedded in a in a linear arrangement protein bilayer (C) several ribosomes attached to a (B) proteins embedded in a single mRNA phospholipid bilayer (D) many ribosomes attached to a (C) proteins embedded in a polymer of strand of endoplasmic reticulum glucose molecules 12. Keeping in view the “fluid mosaic (D) proteins embedded in a model” for the structure of cell carbohydrate bilayer membrane, which one of the following 18. The main arena of variuos types of statements is correct with respect to activites of a cell is [2010] the movement of lipids and proteins (A) Plasma membrane from one lipid monolayer to the other (B) Mitochondrian (described as flipflop movement)? (C) Cytoplasm [2008] (D) Nucleus (A) While proteins can flip-flop, lipids 19. Which one of the following has its cannot own DNA? [2010] (B) neither lipids, nor proteins can (A) Mitochondria (B) Dictyosome flip-flop (C) Lysosome (D) Peroxisome (C) Both lipids and proteins can flip- 20. Which one of the following structures flop between two adjacent cells is an (D) While lipids can rarely flip-flop effective transport pathway? proteins Cannot [2010] 13. Middle lamella is composed mainly of (A) Plasmodesmata [2009] (B) Plastoquinones (A) Phosphoglycerides (C) Endoplasmic reticulum (B) Hemicellulose (D) Plasmalemma (C) Muramic acid 21. What are those structures that appear (D) Calcium pectate as ‘beads-on-string’ in the 14. Stroma in the chloroplast of higher chromosomes when viewed under plant contains [2009] electron microscope? [2011] (A) Chlorophyll (A) Genes (B) Nucleotides (B) Light-independent reaction (C) Nucleosomes (D) Base pairs enzymes 22. Peptide synthesis inside a cell takes (C) Light-dependent reaction place in [2011] enzymes (A) Ribosomes (D) Ribosomes (B) Chloroplast 15. Cytoskeleton is made up of [2009] (C) Mitochondria (A) Proteinaceous filaments (D) Chromoplast (B) Calcium carbonate granules 23. Important site for formation of (C) Callose deposits glycoproteins and glycolipids is (D) Cellulose microfibrils 16. Plasmodesmata are [2009] [2011] (A) Connection between adjacent (A) Lysosome (B) Vacuole cells (C) Golgi apparatus (D) Plastid (B) Lignified cemented layers between cells 24. Select the the correct statement from (C) Locomotory structures the following regarding cell membrane (D) Membranes connecting the [2012] nucleus with plasmalemma (A) Lipids are arranged in bilayer with 17. The plasma membrane consists polar heads towards the inner mainly of [2010] part

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(B) Fluid mosaic model of cell cilia or membrane was proposed by flagella singer and Nicolson A B C D (C) Na+ and K+ ions move across cell (A) (iv) (ii) (i) (iii) membrane by passive transport (B) (i) (ii) (iv) (iii) (D) Proteins make up 60 to 70% of (C) (i) (iii) (ii) (iv) the cell membrane (D) (iv) (iii) (i) (ii) 25. What is true about ribosomes [2012] 31. The osmotic expansion of a cell kept (A) These are found only in eukaryotic cells in water is chiefly regulated by (B) These are self - splicing introns of [2014] some . (A) Mitochondria (B) Vacuoles (C) The prokaryotic ribosomes are 80 (C) Plastids (D) Ribosomes S, where ‘S’ stands for 32. The solid linear cytoskeletal elements sedimentation coefficient. having a diameter of 6 nm and made (D) There are composed of up of a single type of monomer are ribonucleic acid and proteins known as [2014] 26. Which one of the following does not (A) Microtubules differ in E.coli and Chlamydomonas (B) Microfilaments [2012] (C) Intermediate filaments (A) Cell wall (D) Lamins (B) Cell membrane 33. Which structures perform the (C) Ribosomes function of mitochondria in bacteria? (D) Chromosomal Organization [2014] 27. Ribosomal RNA is actively synthesized (A) Nucleoid (B) Ribosomes in [2012] (C) Cell wall (D) Mesosomes (A) Nucleoplasm (B) Ribosomes 34. Select the correct matching in the (C) Lysosomes (D) Nucleolus following pairs: [2015] 28. A major site for synthesis of lipids is: (A) Rough ER — Oxidation of fatty [2013] acids (A) RER (B) Smooth ER — Oxidation of (B) SER phospholipids (C) Symplast (C) Smooth ER — Synthesis of lipids (D) Nucleoplasm (D) Rough ER — Synthesis of 29. Which one of the following organelle glycogen in the figure correctly matches with 35. Which one of the following is not an its function? [2013] inclusion body found in prokaryotes? (A) Rough endopolasmic reticulum, [2015] formation of glycoproteins (A) Polysome (B) Golgi apparatus, protein synthesis (B) Phosphate granule (C) Golgi apparatus, formation of (C) Cyanophycean granule lipids (D) Glycogen granule (D) Rough endoplasmic reticulum, 36. Nuclear envelope is a derivative of: protein synthesis [2015] 30. Match the following and select the (A) Rough endoplasmic reticulum correct answer [2014] (B) Smooth endoplasmic reticulum A Centriole (i) lnfoldings in (C) Membrane of Golgi complex mitochondria (D) Microtubules B Chlorophyll (ii) Thylakoids C Cristae (iii) Nucleic acids 37. DNA is not present in [2015] D Ribozymes (iv) Basal body (A) Mitochondria (B) Chloroplast (C) Ribosomes (D) Nucleus

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38. Which of the following structures is not found in prokaryotic cells? 44. Balbiani rings are sites of: [2015] [2015] (A) RNA and protein synthesis (A) Plasma membrane (B) Lipid synthesis (B) Nuclear envelope (C) Nucleotide synthesis (C) Ribosome (D) Polysaccharide synthesis (D) Mesosome 45. The chromosomes in which 39. Which of the following are not centromere is situated close to one membrane-bound? [2015] end are [2015] (A) Mesosomes (B) Vacuoles (A) Sub-metacentric (C) Ribosomes (D) Lysosomes (B) Metacentric 40. Cellular organelles with membranes are (C) Acrocentric [2015] (D) Telocentric (A) Lysosomes, Golgi apparatus and 46. The stage during which separation of mitochondria the paired homologous chromosome (B) Nuclei, ribosomes and begins is [2018] mitochondria (A) Diakinesis (B) Dipotene (C) Chromosomes, ribosomes and (C) Pachytene (d) Zygotene endoplasmic reticulum 47. The Golgi complex participates in (D) Endoplasmic reticulum, [2018] ribosomes and nuclei (A) Respiration in bacteria 41. Cell wall is absent in: [2015] (B) Formation of secretory vesicles (A) Nostoc (C) Fatty acid breakdown (B) Aspergillus (D) Activation of amino acid (C) Funaria 48. Which of the following is true for (D) Mycoplasma nucleolus ? [2018] 42. A protoplast is a cell [2015] (A) It takes part in spindle formation. (A) without cell wall (B) It is a membrane-bound (B) without plasma membrane structure. (C) without nucleus (C) Larger nucleoli are present in (D) undergoing division dividing cells. 43. Match the columns and identify the (D) It is a site for active ribosomal correct option [2015] RNA synthesis. 49. Select the incorrect match [2018] Column -I Column-II (A) Submetacentric – Lshaped (a) Thylakoids (i) Disc-shaped chromosomes sacs in Golgi (B) Allosomes – Sex chromosomes apparatus (b) Cristae (ii) Condensed (C) Lampbrush chromosomes – structure of Diplotene bivalents DNA (D) Polytene chromosomes – Oocytes (c) Cisternae (iii) Flat of amphibians membranous 50. Many ribosomes may associate with a sacs in single mRNA to form multiple copies of stroma (d) Chromatin (iv) Infoldings in a polypeptide simultaneously. Such mitochondria strings of ribosomes are termed as [2018] (a) (b) (c) (d) (A) Plastidome (A) (iii) (iv) (ii) (i) (B) Polyhedral bodies (B) (iv) (iii) (i) (ii) (C) Polysome (C) (iii) (iv) (i) (ii) (D) Nucleosome (D) (iii) (i) (iv) (ii)

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51. Which of the following events does (a) Golgi (iii) Synthesis of not occur in rough endoplasmic apparatus protein reticulum ? [2018] (b) Lysosomes (iv) Trap waste and (A) Cleavage of signal peptide excretory (B) Protein glycosylation products (C) Protein folding (c) Vacuoles (ii) Formation of (D) Phospholipid synthesis glycoproteins and glycolipids 52. Which of the following cell organelles (d) Ribosomes (i) Digesting is present in the highest number in biomolecules secretory cell? [2019] Choose the right match form options (A) Endoplasmic reticulum given below : (B) Lysosome (A) (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i) (C) Mitochondria (B) (a)-(i), (b)-(ii), (c)-(iv), (d)-(iii) (D) Golgi complex (C) (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i) (D) (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii) 53. Non-membranous nucleoplasmic structure in nucleus are the site for 56. Which is the important site of active synthesis of [2019] formation of glycoproteins and (A) rRNA (B) tRNA glycolipids in eukaryotic cell? [2020] (C) protein synthesis (D) mRNA (A) Golgi bodies (B) Polysomes 54. Which of the following nucleic acids is (C) Endoplasmic reticulum present in an organism having 70 S (D) Peroxisomes ribosome only? [2019] (A) Double stranded DNA enclosed in 57. Which of the following statements nuclear membrane about inclusion bodies is incorrect? (B) Double stranded circular DNA [2020] with histone proteins (A) They lie free in the cytoplasm (C) Single stranded DNA with protein (B) These represent reserve material coat in cytoplasm (D) Double stranded circular naked (C) They are not bound by any DNA membrane (D) These are involved in ingestion of food particles 55. Match the column I with column II. [2019] Column I Column II

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SKILL BOOSTER-1

1. Three of the following satements (C) Osmoregulation regarding cell organelles are correct (D) Circulation. while one is wrong. Which one is 6. Which is present nearest to plasma wrong ? membrane in plant cell (A) Lysosmes are double membraned (A) Secondary wall vesicles budded off form golgi (B) Primary wall apparatus and contain digestive (C) Middle lamella enzymes. (D) Tonoplast. (B) Endoplasmic reticulum consists of 7. The one located inside a vacuole is a network of membranous (A) Tonoplast tubules and helps in transport, (B) Matrix synthesis and secretion. (C) Ergastic substances (C) Leucoplasts are bound by two (D) Cell sap membranes lack pigment but 8. Nuclear membrane is continuous with contain their own DNA and protein synthesizing machinery. (1) rough endoplasmic reticulum (D) Spharosomes are single (2) smooth endoplasmic reticulum Membrane bound and (3) Cell membrane are associated with synthesis and (4) Golgi bodies storage of lipids. 9. In SAT chromosome, SAT (Satellite) is 2. Kinetochore is terminal part of chromosome beyond (A) Granule within centromere secondary constriction. It contains - (B) Surface of centromere (A) DNA (C) Constriction near chromosome (B) RNA end (C) repetitive DNA (D) End of chromosome. (D) None of these 3. A chromosome carrying centromere at 10. Centriole is - one end is (A) Microtubuler and membraneless (A) Acrocentric (B) Absent in Amoeba, red algae, (B) Telocentric blue-green algae conifers and (C) Metacentric angiosperm and made up of (D) Submetacentric. peripheral Triplet microtubuls 4. Organelle connected with lipid (C) Basically locomotary and their synthesis is role in spindle formation is (A) Ribosome secondary (B) SER (D) All of the above (C) Golgi apparatus 11. Mesosomes of prokaryotes perform (D) All the above. function similar to - 5. Major function of contractile vacuole (A) Mitochondria is (B) Peroxysomes (A) Excretion (C) Lysosomes (B) Storage (D) Ribosomes

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12. The main function of lysosomes is - (B) Adenine rich repeats (A) Digestion (C) Guanine rich repeats (B) Replication (D) Thymine rich repeats (C) Translation 19. The main area of variuos types of (D) Translocation activites of a cell is – 13. In a bacterial cell the respiratory (A) Plasma membrane enzymes are found in - (B) Mitochondrian (A) Mitochondria (C) Cytoplasm (B) Chondrisome (D) Nucleus (C) Mesosome 20. An elaborate network of filamentous (D) Centrosome proteinaceous structures present in 14. Choose the incorrect match – the cytoplasm which helps in the (A) Nucleus : RNA maintenance of cell shape is called - (B) Lysosome : protein synthesis (A) Endosplasmic Reticulum (C) Mitochondria : respiration (B) Plasmalemma (D) Cytoskeleton : microtubules (C) Cytoskeleton 15. Fluid mosaic model was given by - (D) Thylakoid (A) Knoll and Ruska 21. Chromosomes composed of :- (B) Singer and Ruska (A) DNA, RNA, Histones, Non histones (C) Singer and Nicolson (B) DNA and Histones (D) Bateson and Punnet (C) DNA and RNA 16. Golgi body concerned with (D) DNA, RNA and Histones (A) Formation of primary lysosome 22. In a human cell 2.2 metre long (B) Formation of Acrosome thread of DNA distributed in :- (C) Formation of Cell  wall material (A) one chromosome (D) All of the above (B) 23 chromosome 17. Select the wrong statement from the (C) x chromosome following- (D) 46 chromosome (A) Both chloroplasts and 23. Who is the controller of cell:- mitochondria contain an inner (A) Mitochondria and outer membrane (B) Nucleus (B) Both chloroplast and (C) Golgi bodies mitochondria have an internal (D) Endoplasmic reticulum compartment, the thylakoid 24. Cell wall :- space bounded by the thylakoid (A) Gives shape to the cell membrane. (B) Protects the cell (C) Both chloroplasts and (C) Helps in cell to cell interaction mitochondria contain DNA (D) All of the above (D) The chloroplasts are generally much larger than mitochondria 25. Labell-A is representing :- A 18. The telomeres of euaryotic (A) Cristae chromosomes consists of short (B) Saccule sequences of - (C) Cisternae (A) Cytosine rich repeats (D) Columns

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A. Cyto- Thylakoid Stroma Granum plasm 26. Diameter of Golgi cisternae is :- (A) 0.5 m – 1.0 m B. Stroma Granum Stroma Thylakoid (B) 0.2 – 1.0 m lamella (C) 1.0 – 4.1 m (D) 10 – 50 nm C. Stroma Thylakoid Stroma Granum 27. Membrane bound vesicular structures lamella formed by the process of packaging in the Golgi apparatus and filled with D. Cyto- Granum Thylakoid Stroma hydrolytic enzymes, are called :- plasm lamella (A) Vacuoles (B) Transitional vesicles 29. In above diagram (Q. 28), which part (C) Lysosomes contains enzymes required for (D) Centrosome carbohydrates and protein synthesis ? 28. The given diagram shows the sectional (A) In B part view of a chloroplast. In which of the (B) In C part following all the four parts labelled as (C) In A part A, B, C, D are correctly identified ? (D) In D part 30. Which one is correct? Satellite Secondary Short arm Short constriction arm Centromere Centromere Centromere Long arm Long arm A B C D A B C D

A B C D A. Telocentric Acrocentric Submetacentric Metacentric chromosome chromosome chromosome chromosome

B. Acrocentric Telocentric Metacentric Submetacentric chromosome chromosome chromosome chromosome C. Submetacentric Metacentric Telocentrci Acrocentric chromosome chromosome chromosome chromosome

D. Metacentric Submetacentric Acrocentric Telocentric chromosome chromosome chromosome chromosome

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52

SKILL BOOSTER-2 1. Dictyosome are 5...... Was a German scientist, who (A) Golgi apparatus of plant cells observed that all plant tissues are (B) Golgi apparatus of animals cells made up of cells. At the same (C) Golgi apparatus of prokaryotes time...... , British scientist studied (D) Mitochondria of Animal cell different type of animal cells. Though 2. Cristae are he was able to observe the nuclei, but (A)The membranous infolding’s of the he could not locate the cell wall, he inner membrane of mitochondria examined and realised that cell wall (B) The membranous infolding’s of forms a unique character of plants. the outer membrane of (A) Rudolf Virchow and Nageli mitochondria respectively (C) The jelly like matrix of (B) Mathias Schleiden and Theodore mitochondria Schwann respectively

(D) F0-F1 particles located on inner (C) Theodore Schwann and Mathias membrane of thylakoid Schleiden respectively membrane (D) Robert Hooke and Purkinje 3. Cell theory which was given by respectively Schleiden and Schwann, did not 6. Find out the incorrect statement - explain as to how the new cells are (A) The inner mitochondrial formed? ...... modified the membrane possesses succinic hypothesis of cell theory to give it a dehydrogenase and cytochrome final shape ? oxidase. (A) Nageli (B) The membrane bound Krebs cycle (B) R.Virchow enzyme is succinic (C) Both (1) and (2) dehydrogenase (D) C.P. Swanson (C) Both mitochondrial membrane are 4. Which of the following observations ultrastructurally similar most strongly support the view that (D) Mitochondrial cristae are sites of mitochondria have elctron transport oxidation-reduction reaction. system/enzymes– (A) Mitochondria have a property to 7. Which of the following statements concentrate in cells which form regarding cilia is not correct– locomotory structures. (A) Cilia contain an outer ring of nine (B) Disruption of mitochondria yields microtubules surrounding two membrane fragments which are microtubules able to synthesize ATP. (B) The organized beating of cilia is (C) Mitochondria have a folded inner controlled by fluxes of Ca2+ membrane. across the membrane (D) A contractile protein capable of (C) Cilia are hair-like cellular utilizing ATP is obtained from appendages mitochondria. (D) Microtubules of cilia are composed of tubulin

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8. Carbohydrates which present in the 15. The fluid nature of the membrane is cell membrane take part in - also important from the point of view (A) Transport of substance of functions like :- (B) Cell recognition (i) Cell growth (C) Attachement to microfilament (ii) Formation of intercellular junctions (D) Attachement to microtubules (iii) Secretions 9. Ingestion of solid food by plasma (iv) Endocytosis membranes is called - (v) Cell division (A) Endosmosis (A) i, iii, iv (B) ii, iii, v (B) Pinocytosis (C) i, iii, iv, v (D) i, ii, iii, iv, v (C) 16. Identify the components labelled A, B, (D) Phagocytosis C, D, E and F in the diagram below from 10. Mitochondrial DNA is - the list (i) to (vi) given alongwith :- (A) Naked Components (B) Circular (i) SER (ii) Ribosome (C) Double stranded (iii) Nucleus (iv) Cytoplasm (D) All the above (v) Nuclear pore (vi) RER 11. Chemical modification of substance The correct components are :- like glycosidation of protein and lipid A B C D E F occur in - (A) v i vi iv ii iii (A) Endoplasmic reticulum (B) i iii ii vi v iv (B) Golgi body (C) iii vi i ii iv v (C) Lysosome (D) iii i ii vi v iv (D) Ribosome A F B 12. Synthesis of cellulose and hemicellulose take place in - (A) Micro bodies (B) Smooth E.R.

(C) golgi complex D (D) Lysosome E C 13. Ground substance present inside the 17. Which cell organelle divides the mitochondria is called - intracellular space into two distinct (A) Stroma compartments, i.e. luminal (inside) and (B) Matrix extra luminal (cytoplasm) (C) Cell sap compartments ? (D) Cytoplas (A) Golgibody 14...... can not pass through the lipid (B) Mitochondria bilayer, they require a carrier protein of (C) Endoplasmic reticulum the membrane to facilitate their (D) Lysosome transport across the membrane 18. According to widely accepted "fluid (A) Nonpolar molecules mosaic model" cell membranes are (B) Polar molecules semi–fluid, where lipids and integral (C) Hydrophobic molecules proteins can diffuse randomly. In (D) Both (2) and (3) recent years, this model has been

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modified in several respects. In this infoldings. regard, which of the following 23. Vacuole in a plant cell :- statements is incorrect – (A) Lacks membrane and contains air (A) Proteins can also undergo flip– (B) Lacks membrane and contains flop movements in the lipid water and excretory substances bilayer (C) Is membrane-bound and contains (B) Many proteins remain completely storage proteins and lipids embeded within the lipid bilayer (D) is membrane-bound and contains (C) Proteins in cell membranes can water and excretory substances travel within the lipid bilayer 24. Match the column–I with column–II (D) Proteins can remain confined and select the correct answer :- within certain domains of the membranes Column–I Column–II (A) Mitochondria (i) 19. The main lipid components of the Flat plant cell membrane are :- Membranous (A) Phosphodiesters ac in stroma (B) Endoplasmic (ii) Cristae (B) Glycocalyx Reticulum (iii) 9 + 0 (C) Peptidoglycan Microtubules (D) Phosphoglycerides (C) Chloroplast (iv) Cytochrome P- 450 20. Semi autonomous cell organelles of (D) Centrioles (v) Membraneless cell are - (E) Glyoxisome Structure (A) Nucleus and chloroplast (vi) 55-S (vii) Gluconeogenes (B) Chloroplast and mitochondria is (C) Vacuoles and golgi complex (viii) Microbody (D) Ribosome and lysosome (ix) Ribulose bis Phosphate 21. Chlorophyll in chloroplasts is located (x) Detoxification in – (A) A–iv, B–ii vi, C–iii viii, D–iv (A) Grana x, E–vii ix (B) Pyrenoid (B) A–ii vi, B–iv, x C–i ix, D–iii (C) Stroma v, E–vii, viii (D) Both grana and stroma (C) A–v ix, B–vi x, C–vii i, D–viii ii, E– 22. Which of the following statements iv iii regarding mitochondrial membrane is (D) None of these notcorrect? 25. Which one of the following (A) The outer membrane resembles statements is not correct ? a sieve (A) The magnesium found in (B) The outer membrane is Ribosome units permeable (B) Cytochrome P-450 found in Golgi to all kinds of molecules. complex (C) The enzymes of the electron (C) Chloroplasts are semi transfer chain are embedded in autonomous organelle the outer membrane. (D) Nuclear envelope reapper in (D) The inner membrane is highly telophase stage convoluted forming a series of 26. Factory of ribosome in a cell is :–

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(A) Endoplasmic reticulum (D) Sphaerosomes (B) Nucleolus 29. 70s type of ribosomes found in :- (C) Mitochondria (A) Prokaryotic cells (D) Golgi body (B) Prokaryotic cells, chloroplasts and 27. Biogenesis of eucaryotic Ribosomes mitochondria takes place in - (C) Mitochondria (A) Mitochondria (D) Nucleus, mitochondria (B) Chloroplast 30. Cilia and flagella both have - (C) Both (1) and (2) (A) 9 + 2 arrangement of (D) Nucleolus microtubules 28. Which of the following termed as (B) Protective structure of cells highly specialised peroxisomes :- (C) Only present in protozoa Animals (A) Glyoxysomes (D) Only outgrowth structure of (B) Mitochondria cytoplasm (C) Golgibody

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SKILL BOOSTER-3

57

1. Match the Column chitin Column 1 Column 2 (A) (a), (b) and (c) 1. Nucleus (i) Power (B) (a), (c) House of (C) (a), (b) the cell (D) All of the above 2. Mitochondri (ii) Suicidal Bag 4. Depending upon the...... , membrane a of cell proteins can be classified as integral or 3. Lysosome (iii) Site for peripheral :- Various (A) Size Chemical (B) Sedimentation rate reactions (C) Ease of extraction 4. Cytoplasm (iv) Double (D) Molecular weight Membranou 5. Read the following statements? s (a) Cell membrane is Selectively permeable (A) 1.(iv), 2.(i), 3.(ii), 4.(iii) (b) Lipids of plasma membrane are (B) 1.(iv), 2.(i), 3.(iii), 4.(ii) amphipathic in nature (C) 1.(i), 2.(iv), 3.(ii), 4.(iii) (c) Cholesterol absent in the cell (D) 1.(iii), 2.(iv), 3.(i), 4.(ii) membrane of Eukaryotes 2. Which of the following description (A) A and B Statement are true and C describes the cell shown in figure? is false (B) A and C Statement are true and B is false (C) B and C Statement are true and A is false (D) A, B and C cell are true 6. Identify the components labelled A, B,

C, D and E in the diagram (cell

membrane) below from the list (i) to (A) 8 chromosomes, 4 homologous (vii) given along with- pair Components:- (B) 8 chromosomes, 8 homologous (i) Sugar pairs (ii) Protein (C) 16 chromosomes, 8 homologous (iii) Lipid bilayer pair (iv) Integral protein (D) 16 chromohomes, 4 homologous (v) Cytoplasm pairs (vi) Cell wall 3. Which of the following statements are (vii) External protein true? The correct components are- (a) Cell was discovered by Robert (A) A-(i), B-(ii), C-(iii), D-(iv), E-(v) hooke in 1665 (B) A-(ii), B-(i), C-(iii), D-(iv), E-(v) (b) Plasma membrane made up of (C) A-(i), B-(ii), C-(iii), D-(iv), E-(vi) Lipids, proteins and trace (D) A-(i), B-(ii), C-(iii), D-(vii), E-(v) amount of carbohydrates A (c) Cell wall of plants is made up of B C 58

Cholesterol D E

cellular polymers to monomers (C) Golgi complex 3 Synthesize proteins to be used inside 7. Which is not the function of cell wall ? the cell I. Provides shape to the cell (D) Free 4. Synthesize II. Protects the cell from mechanical ribosomes proteins to be used outside damage and infection the cell III. Helps in cell to cell interaction (E) Lysosomes 5. Move materials out IV. Provides barrier to undesirable of the cell macromolecules

V. Imbibition of water Codes : A B C D E (A) Only III (B) Only IV (A) 2 1 5 3 4 (B) 3 1 2 4 5 (C) Only II, III and IV (D) None (C) 4 1 5 3 2 (D) 5 4 3 1 2 8. (a) granular structure 11. Which one is the wrong statement (b) first observed under the electron microscope as dense particles by George regarding cell organelles Palade (A) Lysosomes are double (c) composed of RNA and proteins membraned vesicles budded off (d) not surrounded by any membrane from Golgi bodies and contain Above given statements are true for digestive enzymes which cell organelle ? (B) Endoplasmic reticulum consists (A) Nucleolus (B) Ribosomes of a network of membranous (C) Cristae (D) Chloroplast tubules and helps in transport, 9. Match the following - synthesis and secretion. (a) tRNA (i) Linking of (C) Leucoplasts are bounded by two amino acids (b) mRNA (ii) Transfer of membranes, lack pigments but genetic contain their own DNA and information protein synthesising machinery. (c) rRNA (iii) Nucleolar organising (D) Sphaerosomes are single region membrane bound and are (d) Peptidyl (iv) Transfer of associated with synthesis and transferase amino acid from storage of lipids. cytoplasm to 12. A red blood corpuscle (RBC) was kept in a solution and treated so that it (A) a–(iv) b–(ii), c–(iii), d–(i) become inside-out. What will be the (B) a–(i), b–(iv),c–3, d–(ii) polarity of the phospholipid bilayer in (C) a–(i), b–(ii),c–(iii), d–(iv) this cell ? (D) a–(i), b–(iii),c–2, d–(iv) 10. Match the following cellular organelles with their functions : (A) (B)

(A) Rough 1. Makes ATP endoplasmic reticulum (C) (D) (B) Mitochondria 2. Convert

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(B) ATP in respiration Hydrophilic end (C) use of O2 in photosynthesis Hydrophobic end (D) Excretion of O2 in respiration Phospholipid 19. The function of peroxisomes is 13. Which of following organisms has cell (A) H2O2 destruction wall ? (B) conversion of fats to (A) Euglena carbohydrates (B) Mucor (C) detoxification of heavy metals (C) Mycoplasma (D) oxidative phosphorylation (D) Amoeba 20. Match the following with correct 14. Which of following is mismatched ? combination (A) Algae - Galactans, Column I Column II mannose (A) Endoplas 1. stack of (B) Fungi - Cellulose mic cisternae reticulum (C) Dinoflagellate - Stiff cellulose (B) Spheroso 2. Store oils or plate mes fats (D) Bacteria - Peptidoglycans (C) Dictyoso 3. Synthesis and mes storage of lipids 15. Telomeres (D) Peroxiso 4. Photorespiration (A) Initiate RNA synthesis mes (B) Help chromoatids to move (E) Elaioplast 5. Detoxification s of drugs towards poles (A) a -5, b-3, c-1, d-4, e-2 (C) Seal end of chromosomes (B) a -5, b-3, c-2, d-4, e-1 (D) Identify correct members of (C) a -2, b-3, c-1, d-4, e-5 homologous pairs of chromosomes. (D) a -3, b-4, c-1, d-5, e-2 16. (a) Minute vesicles 21. Which group of organelles is double (b) Membrane bound membranous? (c) Contained enzymes (A) Nucleus, Mitochondria & E.R. (d) Present in plant and animals (B) Nucleus, Mitochondria & Above statements are correct for :- Chloroplast (A) Plastids (C) E.R., Golgi body & Lysosome (B) Microbodies (D) None of the Above (C) Nucleoli 22. Name the outer most boundary of (D) Satellite bodies plant and Animal cell respectively 17. Genes present in the cytoplasm of (A) Plasma membrane & cell-wall eukaryotic cells are found in (B) Cell-wall & middle lamella (A) Lysosomes and peroxisomes (C) Cell-wall & plasma membrane (B) Mitochondria and inherited via egg (D) Plasma membrane & middle cytoplasm lamella (C) Golgi bodies and smooth 23. Which cell organelle is known as endoplasmic reticulum “Power House of the cell” (D) Plastids and inherited via male (A) Mitochondria gamete. (B) Glogi body 18. Oxidative phosphorylation means (C) Endoplasmic Reticulum formation of (D) Vacuole (A) ATP in photosynthesis

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24. Which one of the following is not 27. Which component has sessile particles considered as a part of the ? endomembrane system? (A) A (B) B (A) Endoplasmic reticulum (E.R.) (C) D (D) E (B) Golgi body 28. Cristae are infoldings of ...... present (C) Lysosome toward the ...... (D) Mitochondria (A) E and B (B) B and C Direction No. 25 to 30 are based on same (C) Cand D (D) F and D diagram 29. Single circular DNA molecule is found

E in :- C B D A (A) B (B) D

25. Which representsF aqueous (C) E (D) C compartments ? 30. Labelled-D contains :- (A) A, B G (B) D, C (A) A few RNA molecules (C) A, D (D) B, D (B) 70s ribosome 26. What is the average value of labelled F (C) Enzymes ? (D) Circular DNA (A) 0.2 µm (B) 0.5 µm (A) B, D (B) A, B, D (C) 1.0 µm (D) 4.1 µm (C) B, C, D (D) A, B, C, D

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EDU Catalyzer-1 1 2 3 4 C D B B EDU Catalyzer-2 1 2 3 4 B B D B EDU Catalyzer-3 1 2 3 4 C B B B EDU Catalyzer-4 1 2 3 4 C D B A EDU Catalyzer-5 1 2 3 4 A C A C EXERCISE -1 1 2 3 4 5 6 7 8 9 10 C D C B D D B B A C 11 12 13 14 15 16 17 18 19 20 C A C C C A D D B D 21 22 23 24 25 26 27 28 29 30 A A C C C A B A B D 31 32 33 34 35 36 37 38 39 40 A A D D A A C C C C 41 42 43 44 45 46 47 48 49 50 D D B D B B A C B B 51 52 53 54 55 56 57 58 59 60 D C D D D D C D B C 61 62 63 64 65 66 67 68 69 70 C C D A D D D C C D 71 72 73 74 75 76 77 78 79 80 B D B D D C D C C A 81 82 83 84 85 86 87 88 89 90 B D D C B D B C A D 91 92 93 94 95 96 97 98 99 100 B B C C B C D C D A 101 102 103 104 105 106 107 108 109 110 B A C D B D C D A C 111 112 113 114 115 116 117 118 119 120 D D B D B B C B A A 121 122 123 124 125 126 127 128 129 D B B A B D D A B

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EXERCISE -2 1 2 3 4 5 6 7 8 9 10 A A A A B D C D A C 11 12 13 14 15 16 17 18 19 20 C D D B A A B C A A 21 22 23 24 25 26 27 28 29 30 C A C B D B D B D A 31 32 33 34 35 36 37 38 39 40 B B D C A A C B C A 41 42 43 44 45 46 47 48 49 50 D A C A C B D D D C 51 52 53 54 55 56 57 D D A D C A D SKILL BOOSTER -1 1 2 3 4 5 6 7 8 9 10 A A B B C A D A C A 11 12 13 14 15 16 17 18 19 20 A A C B C D B C C C 21 22 23 24 25 26 27 28 29 30 A D B D C A C B C A SKILL BOOSTER -2 1 2 3 4 5 6 7 8 9 10 A A B B B C B B D B 11 12 13 14 15 16 17 18 19 20 B C B B D C C A D B 21 22 23 24 25 26 27 28 29 30 A C D B B B D A B A SKILL BOOSTER -3 1 2 3 4 5 6 7 8 9 10 A A C C A A D B A C 11 12 13 14 15 16 17 18 19 20 A A B B C B B B A A 21 22 23 24 25 26 27 28 29 30 B C A D D B D C B D

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