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1

A student has drawn a cell structure as seen using a light microscope. The magnification of the drawing is ×600. The length of the structure on the drawing is 6 mm. What is the actual length of the cell structure?

1. Cell structure  →  1.1. The microscope in cell studies

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2

The electron micrograph shows part of a eukaryotic cell. Which of the labelled organelles is a site of protein synthesis?

6. Nucleic acids and protein synthesis  →  6.2. Protein synthesis

1. Cell structure  →  1.2. Cells as the basic units of living organisms

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3

Inside a cell, a damaged mitochondrion can be surrounded and enclosed by a membrane to form a vesicle. What happens after the fusion of a lysosome with the vesicle?

5. The mitotic cell cycle  →  5.1. Replication and division of nuclei and cells

12. Energy and respiration  →  12.2. Respiration

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4

Which units are the most appropriate to record the diameter of a lymphocyte and a red blood cell?

1. Cell structure  →  1.1. The microscope in cell studies

8. Transport in mammals  →  8.1. The circulatory system

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5

Which structures will be present in a cell that causes cholera?

10. Infectious diseases  →  10.1. Infectious diseases

1. Cell structure  →  1.2. Cells as the basic units of living organisms

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6

What may take place during a hydrolysis reaction?

2. Biological molecules  →  2.2. Carbohydrates and lipids

12. Energy and respiration  →  12.2. Respiration

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7

The table shows some information about four carbohydrate polymers. polymer α-1,4 glycosidic bonds α-1,6 glycosidic bonds shape of molecule   helical key   branched = present   helical = absent   branched Which two polymers form starch?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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8

Which molecule in the key is sucrose?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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9

Which statements about triglycerides and phospholipids are correct?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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10

When proteins are mixed with some organic solvents, hydrophobic interactions and hydrogen bonding are changed in the protein molecules. Which levels of protein structure would be affected?

2. Biological molecules  →  2.3. Proteins

2. Biological molecules  →  2.4. Water

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11

The rate of enzyme-catalysed reactions in human cells is regulated. What may be involved in such regulation?

3. Enzymes  →  3.2. Factors that affect enzyme action

3. Enzymes  →  3.1. Mode of action of enzymes

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12

The graphs show the effects of temperature and pH on enzyme activity. rate of reaction rate of reaction Q P R S temperature pH Which statement is a correct explanation of the enzyme activity?

3. Enzymes  →  3.2. Factors that affect enzyme action

3. Enzymes  →  3.1. Mode of action of enzymes

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13

Which statement correctly describes the action of competitive enzyme inhibitors?

3. Enzymes  →  3.2. Factors that affect enzyme action

3. Enzymes  →  3.1. Mode of action of enzymes

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14

Which row correctly links molecules in the cell surface membrane with their roles?

4. Cell membranes and transport  →  4.1. Fluid mosaic membranes

2. Biological molecules  →  2.2. Carbohydrates and lipids

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15

Antimycin is a chemical that inhibits the function of mitochondria. Which methods of transport across the cell surface membrane would be inhibited by antimycin?

4. Cell membranes and transport  →  4.2. Movement into and out of cells

7. Transport in plants  →  7.2. Transport mechanisms

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16

Which statements about the cell cycle are correct?

5. The mitotic cell cycle  →  5.1. Replication and division of nuclei and cells

5. The mitotic cell cycle  →  5.2. Chromosome behaviour in mitosis

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17

The diagram shows cells in different stages of the cell cycle. Which is the last stage before cytokinesis?

5. The mitotic cell cycle  →  5.2. Chromosome behaviour in mitosis

5. The mitotic cell cycle  →  5.1. Replication and division of nuclei and cells

16. Inheritance  →  16.1. Passage of information from parents to offspring

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18

How many of the listed structures typically contain genetic material that has telomeres?

5. The mitotic cell cycle  →  5.1. Replication and division of nuclei and cells

1. Cell structure  →  1.2. Cells as the basic units of living organisms

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19

What does the enzyme DNA polymerase synthesise in a cell?

6. Nucleic acids and protein synthesis  →  6.2. Protein synthesis

6. Nucleic acids and protein synthesis  →  6.1. Structure of nucleic acids and replication of DNA

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20

21.2% of the bases in a molecule of DNA are cytosine. What percentage would be adenine?

6. Nucleic acids and protein synthesis  →  6.1. Structure of nucleic acids and replication of DNA

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21

One gene provides the code for the production of which type of molecule?

6. Nucleic acids and protein synthesis  →  6.2. Protein synthesis

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22

The table shows the mode of action of two antibacterial drugs that can affect the synthesis of proteins. antibacterial drug rifampicin streptomycin mode of action binds to RNA polymerase causes errors in translation If bacteria are treated with both drugs, what will be the immediate effects?

6. Nucleic acids and protein synthesis  →  6.2. Protein synthesis

10. Infectious diseases  →  10.2. Antibiotics

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23

The diagrams show transverse sections of parts of a plant. root stem leaf In the transverse sections, which tissues transport sucrose?

7. Transport in plants  →  7.1. Structure of transport tissues

7. Transport in plants  →  7.2. Transport mechanisms

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24

Which statement describes movement through a plant in the apoplast pathway?

4. Cell membranes and transport  →  4.2. Movement into and out of cells

7. Transport in plants  →  7.2. Transport mechanisms

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25

Which changes to the water potential and the volume of liquid in the phloem occur when sucrose is moved from the phloem sieve tube to an actively dividing root tip?

4. Cell membranes and transport  →  4.2. Movement into and out of cells

7. Transport in plants  →  7.2. Transport mechanisms

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26

The diagram shows the results of an experiment using leaves with the same surface area from two different species of plant. Each leaf was left on a balance in daylight in a closed room and its mass recorded at 1 hour intervals. time / hours mass of leaf leaf 1 leaf 2 Which features of leaf 2 could explain these results?

14. Homeostasis  →  14.2. Homeostasis in plants

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27

Which evidence supports the cohesion-tension theory for the movement of water in flowering plants?

4. Cell membranes and transport  →  4.2. Movement into and out of cells

7. Transport in plants  →  7.2. Transport mechanisms

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28

Cardiac muscle is made up of many fibres that form the walls of the chambers of the heart. When the heart contracts, these fibres shorten in length so the muscle creates a force that exerts a pressure on the blood, causing it to move. Which statement explains the difference in thickness of the walls of ventricles of the heart?

8. Transport in mammals  →  8.3. The heart

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29

Which reactions take place at a higher rate in a capillary in an alveolus than in a capillary in active muscle?

8. Transport in mammals  →  8.2. Transport of oxygen and carbon dioxide

12. Energy and respiration  →  12.2. Respiration

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30

The diagram shows the effect of three different concentrations of carbon dioxide on the oxygen dissociation curve for human haemoglobin. X Y Z percentage saturation of haemoglobin with oxygen partial pressure of oxygen / kPa X = partial pressure of carbon dioxide: 3.0 kPa Y = partial pressure of carbon dioxide: 5.0 kPa Z = partial pressure of carbon dioxide: 7.0 kPa What effect does increasing carbon dioxide concentration have on haemoglobin?

8. Transport in mammals  →  8.2. Transport of oxygen and carbon dioxide

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31

The graph shows the changes that take place in the volume of the left ventricle during one cardiac cycle. Which point on the graph represents the start of atrial systole?

8. Transport in mammals  →  8.3. The heart

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32

The following tissues carry an electrical impulse during the cardiac cycle. atrioventricular node muscle wall of atria Purkyne tissue sinoatrial node In what order does the electrical impulse travel during the cardiac cycle?

8. Transport in mammals  →  8.3. The heart

15. Control and coordination  →  15.1. Control and coordination in mammals

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33

Some of the effects of smoking are listed. It causes coughing. It increases blood pressure. It decreases the transport of oxygen. It increases the risk of cancer. It prevents cilia from moving. Which components of tobacco smoke cause these effects?

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34

The photomicrograph shows a section through part of a bronchus wall. X What is the function of the tissue labelled X?

9. Gas exchange  →  9.1. The gas exchange system

8. Transport in mammals  →  8.1. The circulatory system

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35

Which of the following increase the risk of contracting TB?

10. Infectious diseases  →  10.1. Infectious diseases

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36

One control method to reduce the spread of malaria is to use an insecticide. It can be used to treat mosquito nets. Another control method is to completely cover areas of water with insoluble polystyrene balls that float on the surface. Using this information, what are the reasons for these control methods?

10. Infectious diseases  →  10.1. Infectious diseases

11. Immunity  →  11.2. Antibodies and vaccination

18. Classification, biodiversity and conservation  →  18.3. Conservation

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37

What is not an example of antibiotic action?

10. Infectious diseases  →  10.2. Antibiotics

17. Selection and evolution  →  17.2. Natural and artificial selection

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38

Which row correctly identifies the roles of B-lymphocytes and T-lymphocytes?

11. Immunity  →  11.1. The immune system

11. Immunity  →  11.2. Antibodies and vaccination

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39

A person’s blood group is determined by antigens present on the red blood cells. The table shows the antigens and antibodies in the blood of people with different blood groups. blood group antigens on red blood cells antibodies in plasma A A anti-B B B anti-A AB A and B neither O neither anti-A and anti-B During a blood transfusion, it is essential that the recipient’s blood does not contain antibodies to the donor’s blood. Which blood groups can be given to a person with blood group B?

11. Immunity  →  11.2. Antibodies and vaccination

8. Transport in mammals  →  8.1. The circulatory system

11. Immunity  →  11.1. The immune system

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40

An enzyme hydrolyses the two heavy polypeptide chains of an antibody molecule. The hydrolysis occurs at the hinge region and breaks the antibody into three fragments. How many of these fragments are able to bind to antigens?

2. Biological molecules  →  2.3. Proteins

11. Immunity  →  11.2. Antibodies and vaccination

19. Genetic technology  →  19.1. Principles of genetic technology

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