Standard 1 Answer Key

Standard 1 answer key.

SB1a. Cell theory: states all cells come from pre-existing cells, all things are made up of cells, cells are the basic unit of life. Theorists include: Virchow, Schliden, Schwann, Hooke, and Leuwenhoek.

1. Prokaryotic cells are cells with no membrane bound organelles, no true nucleus and contain both a cell membrane and cell wall. Eukaryotic cells are cells with a true nucleus; membrane bound organelles, larger and more complex.

a. Examples: prokaryotic: bacteria, eukaryotic: plant, animal, fungi and protista cells

2. Cell membrane-protect and regulate entry and exit of the cell

Cell wall-sturdy protection, extra barrier around the cell

Golgi apparatus- packs and ships proteins

Mitochondria-power house, where cellular respiration occurs

Nucleus-control center, houses DNA, regulates cell activities

Nucleolus-ribosome assembly

Ribosomes-assembles proteins

Rough endoplasmic reticulum (ER)-protein synthesis

Smooth ER-lipid synthesis

Vacuoles- storage

Lysosomes-break down dead/dying organelles (cleanup crew)

Microtubules/filaments- internal cell transport and support

Chloroplast-site of photosynthesis

Vesicles-small storage, aid in endocytosis

Flagella-long whip like structures used in movement

Cilia-hair like projections that beat back and forth for movement

a. Prokaryotic cells contain: cell membrane, cell wall, ribosomes, flagella

b. Eukaryotic animal cells: cell membrane, microtubules, smooth and rough ER, ribosomes, mitochondria, nucleus and nucleolus, golgi apparatus, lysosomes

c. Eukaryotic plant cells: cell membrane, microtubules, smooth and rough ER, ribosomes, mitochondria, nucleus and nucleolus, golgi apparatus, cell wall, vacuoles

3. The cell membrane is composed of phospholipids, proteins and carbohydrates.

a. The role of the phospholipids is to make up the majority of the membrane. The heads are polar and the tails are nonpolar. b. The role of the proteins are to act as carriers and channels to assist materials through the membrane.

c. The carbohydrate chains are used as identification as to what type of cell it is.

-The cell membrane’s job is to act as barrier and regulate what enters and leaves the cell. It is selective in what comes in and out and also how it enters the cell.

-the membrane is called a fluid mosaic model because it has a flexible but sturdy structure and the organization of arrangement of proteins and carbohydrate chains are not in a set pattern.

4. Active transport requires energy to move materials across the cell membrane. It is moving it from an area of low concentration to an area of high concentration. This requires energy and there are 2 major forms of this process: endocytosis and exocytosis.

Endocytosis: moving materials into the cell, the materials fuse to the cell membrane and the membrane forms a vesicle around the materials, it then pulls it into the cell and then releases inside.

Two forms of this process: pinocytosis-cell drinking, or bringing in small molecules

Phagocytosis-cell eating, or bringing in large molecules

Exocytosis: the materials are transported outside of the cell by fusing with the interior of the cell membrane and then a vesicle forming around it by the cell membrane, pulling it out of the cell and releasing it outside into the surrounding environment.

Passive transport-requires no energy, movement of materials from an area of high to low concentration.

Three types of passive transport: diffusion, osmosis (diffusion of just water), and facilitative diffusion where carrier proteins assist molecules too large to fit through the membrane still from an area of high to low diffusion.

Homeostasis is the regulation and maintaining of an internal balance in the body.

a. This includes regulation of the amounts of water, electrolytes, minerals, body temperature, pH of the blood, blood sugar, and internal cell environments. This process is maintained by negative feedback.

6. *Mitosis is the cell division that takes place in body or somatic cells that allows them to reproduce. The daughter cells are identical to the parent cells.

*Meiosis is the cell division that takes place in the sex cells (eggs/sperm) that allows for the creation of new sex cells. The daughter cells are genetically different from the parent cells due to crossing over during prophase 1 of meiosis.

Mitosis results in 2 daughter cells from each parent, meiosis results in 4 sperm or 1 egg and 3 polar bodies from parent cell.

Mitosis has 4 stages, meiosis has 8 stages.

SB1b. 1. A catalyst decreases the activation energy needed to start a chemical reaction and it increases the rate of the chemical aeration without being used up itself.

2. Enzymes act as biological catalysts and bind to substrates to speed up reactions, by lowering the activation energy, without being used up themselves. 3. the enzyme substrate complex is when the enzyme has a specific substrate (molecule) that it fits perfectly with (forming an active size) and helps aid in the reaction. The active site is specific and the enzyme fits into the substrate like a key would fit into a specific lock and work.

SB1c. 1. A) carbohydrates- monomer is monosaccharide, polymer is a polysaccharide, major function-primary source of energy.

B) proteins-monomer is amino acid, polymer is a folded polypeptide chain, major functions-biological catalysts, hormones, strong muscles

C)nucleic acids-monomer is nucleotides (5 carbon sugar, phosphate and nitrogen base), polymer-chains of nucleotides joined together forming nucleic acid, function- DNA and RNA

D) lipids-monomers fatty acid tails and glycerol backbone, polymers- saturated and unsaturated fats (dependent upon presence and number of double bonds), function- back up energy, hormones, healthy skin, hair

SB1d. 1. diffusion, osmosis (diffusion of just water) both are types of passive transport moving from an area of high to low concentration.

A. Concentration gradient is the uneven distribution of molecules across a membrane, these processes help to maintain an even number or equilibrium across membranes.

2. adhesion is when the molecules of a substance have a greater attraction to their surroundings than themselves. Ex. Water forming a meniscus curve in a graduated cylinder (forms a smile, or curves up the sides of the glass). Cohesion is when the molecules of a substance have a greater attraction to themselves than to their surroundings. Ex. Water droplets falling from a faucet.

3. Water has the following properties: high specific heat capacity(ability to hold large amounts of energy for a period of time, slow to release that energy) hydrogen bonding, allow water molecules to bond to themselves.

4. solute: the substance being dissolved, solvent: the substance that is dissolving the solute, solution: the substance formed when one substance dissolves into another substance.

A. 5. Osmotic solutions: isotonic environments: cell has the same concentration internally as the external environment. Hypertonic environment: the water concentration inside the cell is higher than that of the surrounding environment. Hypotonic environment: there is less water inside the cell than in its surroundings.

Standard 2:

(SB2a)

1. DNA contains deoxyribose sugar and nitrogen bases: Adenine, thyamine, guanine and cytosine. Genetic code of the body. It is a double helix with the rungs of the ladder being held together by hydrogen bond, the sides/backbone held together by covalent bonds RNA contains ribose sugar and nitrogen bases: adenine, guanine, cytosine, and uracil. Job is to give directions to form proteins. (3 forms: tRNA, mRNA, rRNA), structure is a single strand

(SB2b)

2. DNA replication is the process of copying DNA in the nucleus. DNA polymerase and helicase are needed for the process. Helicase is used to unzip the DNA/break the hydrogen bonds that hold the nitrogen bases together between the strands, DNA polymerase builds the complementary strands and proof reads for errors.

3. DNA serves as the template for making mRNA. This also occurs in the nucleus. The process is known as transcription. The enzymes involved are helicase and RNA polymerase.

4. The mRNA is passed through the nuclear pores and out into the cytoplasm to a ribosome. Here translation occurs. rRNA assembles the ribosome, the mRNA is translated as tRNA brings the complementary amino acid to the ribosome to form the polypeptide chain.

(SB2c)

5. The stages of meiosis are prophase 1: homologous chromosomes pair up, crossing over, nuclear envelope breakdown; metaphase 1: homologous chromosomes line up at the equator; anaphase 1: spindle fibers pull the homologous chromosomes apart and away to the poles; telophase 1: nuclear envelopes reform, spindle breaks down. Prophase 2: nuclear envelope breaks down, spindle forms; metaphase 2: sister chromatids line up at the equator; anaphase 2: sister chromatids separate and are pulled to opposite poles; telophase 2: spindle breaks down, nuclear envelopes reform (4 daughter cells produced)

6. Crossing over occurs during prophase 1 of meiosis. It happens when homologous chromosomes exchange pieces of themselves with each other.

7. Oogenesis is the production of eggs in females, 1 egg is produced along with 3 polar bodies. The egg provides all the organelles and most of the cytoplasm if fertilization occurs.

a. Spermatogenesis- production of sperm in males. Produces 4 viable sperm.

8. Traits are distinguishing characteristics that are inherited, they are passed from parents to offspring through DNA

9. Heterozygous-different alleles for gene ex. Bb, homozygous- same allele for gene ex. bb or BB

10. Gene is a piece of DNA that provides a set of instructions to a cell to make a certain protein, allele are different forms of a gene that may occur at a specific site or locus. 11. Genome is all of an organism’s genetic information or material. Genotype is the genetic material that a person has for specific traits, the phenotype is the physical appearance based on the genetic material.

12. Dominant alleles are the alleles that are expressed when either there are two of the same or two different alleles of a gene are present (it is the stronger allele). Recessive alleles are only expressed when 2 of the same allele are present, they will not appear if a dominant allele is present.

13. In the monohybrid cross of a (Pp) parent crossed with a (pp) parent the genotypes of offspring would be 50% Pp, 50% pp, Phenotypes would be 50% purple, 50% white

14. In a monohybrid cross only one set of alleles are being examined. In a dihybrid cross two different alleles are being passed down independently of one another.

Dihybrid cross

15. Law of independent assortments states that allele pairs separate independently of each other during gamete formation or meiosis. (in other words, traits separate independently of one another)

Law of segregation states that traits are discrete units that are given one copy from mom and one copy from dad.

16. Sex-linked traits are traits that are inherited on the sex chromosome (X). Males may never inherit more than 1 (X) chromosome from the mother, so they only contain 1 (X) and 1 (Y) and would either display or not have the trait.

17. A carrier of a trait has both a dominant and recessive allele and doesn’t show or display the trait because it is a recessive allele; they can pass it on to their offspring but can’t display the trait themselves.

18. Incomplete dominance-when the heterozygous phenotype is a blend or mix of the two homozygous phenotypes, neither allele is more dominant over the other so you get a blend of the two traits. (pink four o clock flowers)

a. Co-dominance is when both homozygous traits appear in the heterozygous phenotype (Dalmatian)

b. Polygenic traits are traits that are produced by two or more genes ex. skin color (SB2d)

19. Mutation-change in the organism’s DNA

20. Point mutation is a mutation in which one nucleotide is substituted for another. May or may not affect the reading frame.

a. Frameshift mutation is a mutation that involves the insertion or deletion of a nucleotide in the DNA sequence. (affects the reading frame, typically changes the structure)

21. Agents in the environment that can change DNA

22. Translocation (exchange of genes of nonhomologous chromosomes); inversion(when a chromosome exchanges genes by folding over on itself); duplication (an extra copy of an existing gene appears on a chromosome); deletion (a gene is deleted from the chromosome)

23. Cloning is the process of making an identically genetic copy of a gene or organism. Problems include: environment affects the expression of genes, typically not as healthy, very expensive and time consuming to get one possible out of hundreds/thousands of attempts.

24. Transgenic is a genetically modified organism, plant or animal. It has one or more genes from another organism inserted into its genome. Used to produce genetically engineered plants and animals (farming/agriculture)

(SB2e)

25. The main advantage of asexual reproduction is to produce identical offspring without a mate and favors a non changing environment. The disadvantage is also that there is no genetic variation. Advantage of sexual reproduction is to produce genetically different offspring with a mate. Disadvantage is that a mate is required and typically can only occur during certain times of the year.

26. Binary fission is the asexual reproduction in bacteria cells, it allows for quick and efficient reproduction.

27. Vegetative reproduction is a method of asexual reproduction when a piece of the plant is attached back to the parent plant and is used to harvest many plants at a given time.

(SB2f)

28. DNA fingerprint is a representation of part of an individual’s DNA that can be used to identify a person at the molecular level. It can be used to identify missing persons, criminals, etc.

29. The changing of an organism’s DNA to give the organism new traits.

30. Type of genetic manipulation that have genes that are purposely turned off. This allows scientists the ability to study specific changes in gene expression.

31. We don’t have any long term research to see the potential harm/threats or changes in genetically modified organisms. Also it can affect the natural biodiversity that exists and upset the balance.

32. The human genome project is to map and sequence all of the DNA base pairs of the human chromosomes and to identify all of the genes within the sequence. The purpose is to help identify genetic differences that lead to potential illness and disease. 33. Genetic screening is the process of testing DNA to determine the risk of having or passing on a genetic disorder or disease. It allows couples the opportunity to make wise choices in deciding to have children and prepare for any possible disorders that they may also encounter themselves.

34. Gene therapy is used to replace faulty genes with healthy genes in a person’s DNA. This potential advancement of treatment could potential end several disorders and diseases that we face today.

35. Treatments/future cures for genetic disorders, mass production of food (through genetically modified plants and animals), stronger evidence in court for cases involving DNA evidence, mass production of insulin and other medicines through use of genetic engineering.