1. Cell Theory

1 The human being: our species

1. Cell theory

1. Listen and fill in the gaps in the text.

Cell theory

Our most elementary components, CELLS, are too small to be observed with the NAKED eye, so they went unnoticed by HUMANITY for centuries. However, the curiosity and technological capacity of humans led to the DEVELOPMENT of a tool that made them visible to our eyes: the MICROSCOPE.

The first OBSERVATIONS of cells took place in the 17th century, thanks to the work of Robert Hooke and Anton van Leeuwenhoek, who BUILT their own microscopes. In the same century, Marcelo Malpighi analysed many animal and plant TISSUES.

However, it was not until the 19th century that Matthias Jakob Schleiden and Theodor Schwann, in their studies about plant and animal cells, laid the groundwork for cell THEORY. This theory consists of the following POSTULATES:

 The cell is the STRUCTURAL unit of living organisms. All living THINGS are made up of cells.

 The cell is the FUNCTIONAL unit of living organisms, since it is the one that performs the VITAL functions: nutrition, INTERACTION and reproduction.

 The cell is the ORIGINAL unit of living organisms. All cells are CREATED from a pre- existing cell.

2. Place these events on the timeline below.

 The first observations of cells were made thanks to the work of Robert Hooke and Anton van Leeuwenhoek.

 Cells were unnoticed by humanity until the development of the microscope.

 The groundwork for cell theory was laid by Matthias Jakob Schleiden and Theodor Schwann in their studies about plant and animal cells.

 Marcello Malpighi analysed many animal and plant tissues.

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3. Match the terms and definitions.

A. Cell C. The type of cell which makes up the body of all animals. B. Microscope E. Material which stores genetic information. C. Animal eukaryotic cell A. The structural, functional and original unit of living organisms. D. Plant eukaryotic cell F. A hypothesis accepted as true which makes up a theory. E. Genetic material B. A tool used to observe objects which are too small to be seen by the naked eye. F. Postulate D. The type of cell which makes up the body of all plants.

4. Working in pairs, fill in the missing information.

See table 1.2, Cell components

5. Label the picture using the terms in the cloud.

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6. Identify and correct the false statements.

The Golgi apparatus receives substances that come from the rough endoplasmic reticulum and packages them into vesicles. T Ribosomes Mitochondria carry out cellular respiration. Ribosomes are responsible for producing proteins. F A lysosome is a vesicle surrounded by a membrane containing basic acidic substances. F The centrosome is made up of a pair of centrioles. T The vacuole stores water, mineral salts and reserve or waste substances. T If there are associated ribosomes in the endoplasmic reticulum membrane, it is called smooth rough. F The cell membrane is made up of a lipid bilayer. T The nucleus cytoplasm is home to the cell organelles. F Chromatin is the genetic material and is made up of DNA molecules. T Our cells have 23 46 chromosomes. F

7. Working in pairs, fill in the missing information. See the boxes in Section 1.3. and the table in Section 1.4

8. Make a concept map about the 3 vital functions.

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9. Classify the following features of mitosis and meiosis.

CELL DIVISION Mitosis Meiosis -One cell -Two division consecutive -Two daughter divisions cells -Four daughter -Daughter cells cells identical to the -Daughter cells parent cell different from -Diploid cells each other -Haploid cells -Gametes

2. Levels of organisation

10. Listen and label the levels of organisation shown below.

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11. Identify and correct the false statements.

Cells associate to form tissues, which, in turn, form organs, systems and major organ T systems. The cell molecular level contains simple molecules such as water, carbon dioxide, amino acids F or nucleotides. Bone and muscle tissues belong to the organ tissue level. F The system level is made up of a set of organs of the same tissue type which perform a T function in a coordinated way. The level corresponding to the whole living organism is called the organ organism level. F Organisms do not form groups creating higher levels of organisation that are increasingly F complex. The community level is the set of populations that live in the same habitat. T

12. Read the text. Then answer the multiple choice questions.

Complex multicellular organisms are made up of cells that … a) Are specialised. b) Play a specific role within a tissue. c) a) and b).

Epithelial lining and glandular epithelium are types of… a) Nervous tissue. b) Muscle tissue. c) Epithelial tissue.

Tissue which is made up of cells that do not have much differentiation is called… a) Epithelial tissue. b) Connective tissue. c) Nervous tissue.

Muscle fibres which contain fibrillar proteins responsible for muscle contraction and relaxation… a) Make up muscle tissue. b) Are made up of neurons and glial cells. c) Are surrounded by an intercellular substance whose composition is very variable.

13. Classify the following organs into the systems they belong to.

SYSTEMS Circulatory Lymphatic Muscular Skeletal Nervous Endocrine Immune Heart Lymph Skeletal Bones Nerves Endocrine Bone nodes muscles glands marrow Blood Spinal vessels Lymph cord Thymus capillaries Brain Spleen Lymphatic vessels

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14. Label the major organ systems shown below.

15. Read the text and circle the correct option.

Internal environment and homoeostasis The ability to keep vital functions constant/changing depends on the stability of the environment that surrounds each cell/living thing. For this reason, unicellular/multicellular organisms have developed and external/internal environment, made up of all the extracellular fluids/matter that surround all the cells in our organism. The internal environment provides the cells with minerals/nutrients and carbon dioxide/oxygen, and at the same time it collects waste substances and carbon dioxide/oxygen that are constantly excreted/produced by their metabolism.

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16. Decide whether the following features correspond to the external or the internal environment.

ENVIRONMENT

Internal External

Headache Heat

Anxiety Fracture

Low blood sugar Oxygen deficiency

High blood Noise pressure

17. Classify the human systems according to the vital function they contribute the most to.

Human Systems:

Circulatory

Digestive

Nervous

Urinary

Endocrine Reproductive

Respiratory

Immune

Locomotor

18. Match the information.

Through… Humans… C. Pass down their genetic material to successive generations. A. Exchange matter and energy with their surrounding environment. A. Nutrition B. Interact with their environment. B. Interaction B. Receive stimuli from the environment and respond to them. C. Reproduction A. Produce waste, which serves as food for other organisms.

C. Have offspring, which perpetuates the interaction of their species with the environment.

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3. Health and disease

19. Solve the crossword about non-infectious diseases.

Across 2. Hereditary. GENETIC 4. Caused by a blow or injury to an organ. TRAUMATIC 6. The immune response is altered. AUTOIMMUNE 9. Due to bad eating habits or lack of essential nutrients. NUTRITIONAL Down 1. Caused by the progressive loss of organ function. DEGENERATIVE 3. The organs that receive hormones are altered. ENDOCRINE 5. There is an exaggerated immune response to a harmless foreign agent. ALLERGIC 7. Due to the entry of toxic substances into the body. TOXIC 8. Alterations in the degradation or synthesis of molecules occur. METABOLIC

20. Working in pairs, fill in the missing information.

See the table in Section 3.1.

21. Complete the concept map about infectious diseases.

22. Solve the cryptogram.

Tissue transplants are carried out to treat illnesses or to repair damaged parts of

the organism.

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23. Listen and complete the graphic organiser.

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4. Homo sapiens, our species

24. Put the terms in the correct order to complete our taxonomic classification.

25. Match the terms and definitions.

Terms: Definitions:

A. Eukaryotic J. The science that studies how the different species of our planet are related. B. Animal G. A group made up of species considered to be human, whether living or extinct. C. Chordates I. A group of organisms that are able to reproduce with each other and have fertile offspring. D. Mammals A. Describing multicellular organisms made up of eukaryotic cells. E. Primates H. All modern humans since approximately 30,000 years ago. F. Hominids D. Homoeothermic (warm-blooded) vertebrates covered in hair whose females possess mammary glands to feed their offspring. G. Homo E. A group of mammals, most of which have an opposable thumb, which allows them to manipulate tools. H. Homo Sapiens B. A group made up of organisms with animal eukaryotic cells, heterotrophic nutrition and sexual reproduction. I. Species F. A group that includes humans and living apes. J. Taxonomy C. A group that includes vertebrate organisms.