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1

A cell organelle measures 4 × 10–1 mm in diameter. What is the diameter in µm?

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

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

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2

In the following table, which is the correct comparison between light and electron microscopes?

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

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3

Which structures are present in a typical plant cell?

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

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4

Plant cells are stained and then viewed through a light microscope. Which structures would be clearly visible at a magnification of ×400?

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

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

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5

Which type of cell will contain the highest proportion of single membrane-bound structures?

9. Gas exchange  →  9.1. The gas exchange system

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

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6

Four different fruit juices, A, B, C and D, were tested with Benedict’s solution. A second sample of each juice was hydrolysed and tested with Benedict’s solution. The table shows the masses of the precipitates formed. Which juice contains the greatest mass of non-reducing sugar?

2. Biological molecules  →  2.1. Testing for biological molecules

2. Biological molecules  →  2.2. Carbohydrates and lipids

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7

Which molecular bonds will be broken by hydrolysis when a molecule of glycogen is converted to glucose?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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8

Which set of statements correctly describes haemoglobin?

2. Biological molecules  →  2.3. Proteins

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

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9

Some foods contain ‘hydrogenated vegetable oils’. These are unsaturated fats that have been converted to saturated fats. Which property of the fats will have changed?

2. Biological molecules  →  2.2. Carbohydrates and lipids

2. Biological molecules  →  2.4. Water

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10

Which rows show the chemical groups present in the biological molecules listed?

2. Biological molecules  →  2.1. Testing for biological molecules

2. Biological molecules  →  2.2. Carbohydrates and lipids

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11

Which correctly matches the functional and structural features of cellulose, collagen, glycogen or triglyceride?

2. Biological molecules  →  2.2. Carbohydrates and lipids

2. Biological molecules  →  2.3. Proteins

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12

The breakdown of hydrogen peroxide to water and oxygen is catalysed by the enzyme catalase. In an investigation into the effect of pH on the rate of reaction of catalase, potato cubes were added to hydrogen peroxide. Which dependent variable should be recorded?

3. Enzymes  →  3.2. Factors that affect enzyme action

3. Enzymes  →  3.1. Mode of action of enzymes

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13

Which levels of protein structure can determine the specificity of an enzyme?

2. Biological molecules  →  2.3. Proteins

3. Enzymes  →  3.1. Mode of action of enzymes

3. Enzymes  →  3.2. Factors that affect enzyme action

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14

Some inhibitors of enzyme reactions bind to the enzyme / substrate complex. Which statements about this type of inhibition are correct?

3. Enzymes  →  3.2. Factors that affect enzyme action

3. Enzymes  →  3.1. Mode of action of enzymes

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15

What is correct for the cell surface membrane and membranes within cells?

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

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

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16

What supports the view that a membrane protein is involved in active transport?

7. Transport in plants  →  7.2. Transport mechanisms

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17

Strips of plant tissue were immersed in a range of sucrose solutions of different concentrations. Their lengths were measured before immersion and after 30 minutes. The graph shows the ratio of initial length to final length. 1.4 1.2 1.0 0.8 0.6 0.4 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 sucrose concentration / mol dm–3 initial length final length What is a correct description of the change in the cells and in their water potential as the sucrose concentration increases?

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

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18

Which is always true of cytokinesis?

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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19

Which process occurs during prophase of the mitotic cell cycle in an animal cell?

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

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

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20

The diagram shows how genetically identical frogs can be developed from unfertilised frog eggs. The diploid number (2n) for frogs is 26. tadpole develops into frog egg develops into tadpole nucleus destroyed by ultra violet radiation unfertilised frog egg cell taken from frog W V X nucleus taken from cell and injected into egg Which combination of numbers correctly identifies the number of chromosomes in each of the types of cell in the diagram?

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

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

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21

The mechanism of action of four drugs that inhibit DNA replication is stated below. ● Aphidicholine inhibits DNA polymerase. ● Cytarabine is converted into a molecule that can substitute for a DNA nucleotide and also inhibits DNA repair mechanisms. ● Epirubicin inhibits an enzyme involved in the unwinding of DNA and separation of strands. ● Hydroxycarbamide inhibits an enzyme involved in the production of deoxyribonucleotides. Which row correctly matches a drug to an explanation of the mechanism of action?

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

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22

The following events occur during transcription. Bonds break between complementary bases. Bonds form between complementary bases. Sugar-phosphate bonds form. Free nucleotides pair with complementary nucleotides. Before the mRNA leaves the nucleus, which events will have occurred twice?

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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23

Which type of sugar and types of bonds are found in a DNA molecule?

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

2. Biological molecules  →  2.2. Carbohydrates and lipids

2. Biological molecules  →  2.3. Proteins

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24

In an animal cell, which process is dependent upon cell surface area and which process is dependent upon cell volume?

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

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25

Which xerophytic adaptations reduce the water potential gradient?

7. Transport in plants  →  7.2. Transport mechanisms

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

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26

During transpiration, what is the site of evaporation of water in the leaves?

7. Transport in plants  →  7.2. Transport mechanisms

13. Photosynthesis  →  13.1. Photosynthesis as an energy transfer process

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27

The photomicrograph shows a vascular bundle. Which describes the relationship of water potential in the labelled cells?

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

8. Transport in mammals  →  8.1. The circulatory system

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28

The diagram represents the movement of water through a plant. 1 water enters the root 3 water vapour is lost from leaves 2 water passes 2 water passes up the stem up the stem 2 water passes up the stem Which row identifies the processes involved during the stages of water movement shown...

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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29

What is correct for tissue fluid?

8. Transport in mammals  →  8.1. The circulatory system

11. Immunity  →  11.1. The immune system

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30

What happens during ventricular diastole?

8. Transport in mammals  →  8.3. The heart

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31

Which row correctly describes the events 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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32

Which row correctly identifies the structure of an artery compared with a vein seen in transverse section under a light microscope?

8. Transport in mammals  →  8.1. The circulatory system

14. Homeostasis  →  14.1. Homeostasis in mammals

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33

In the lungs, oxygen and carbon dioxide pass through cell membranes by diffusion. Which row is correct?

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

9. Gas exchange  →  9.1. The gas exchange system

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34

A student was asked to describe the differences between four microscope slides of sections taken from different parts of the gas exchange system. slide 1 not present: cartilage, glands present: few goblet cells, ciliated epithelial cells, smooth muscle slide 2 present: incomplete cartilage rings, glands, goblet cells, ciliated epithelial cells, smooth muscle slide 3 not present: cartilage, glands, goblet cells, smooth muscle present: squamous epithelial cells slide 4 present: plates of cartilage, glands, goblet cells, ciliated epithelial cells, smooth muscle Which is the correct identification of the parts of the gas exchange system?

9. Gas exchange  →  9.1. The gas exchange system

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35

A person suffering from mild emphysema stopped smoking cigarettes. Why would this person’s health improve?

9. Gas exchange  →  9.1. The gas exchange system

11. Immunity  →  11.1. The immune system

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

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36

Which disease is not likely to be passed directly from parents to child?

10. Infectious diseases  →  10.1. Infectious diseases

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37

The diagram shows one way of testing the effect of an antibiotic on bacteria. petri dish with nutrient agar containing bacteria disc of filter paper soaked in antibiotic colonies of bacteria grown for 5 weeks diameter of zone measured every week for 5 weeks The table shows the results of testing five different types of bacteria. Zones of less than 13 mm show the presence of resistant bacteria. diameter of zone / mm type of bacteria week 1 week 2 week 3 week 4 week 5 24.10 21.90 19.00 17.60 14.30 18.60 15.40 12.20 9.00 0.00 17.90 12.80 12.40 11.10 10.90 19.40 15.30 13.20 8.10 0.00 22.00 21.00 20.50 20.40 20.40 Which statement can be supported by this data?

10. Infectious diseases  →  10.2. Antibiotics

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

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38

Smallpox has been eradicated, but not malaria or cholera. Which statements correctly explain this?

10. Infectious diseases  →  10.1. Infectious diseases

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39

A square metre of grassland receives about 1 047 000 kJ of solar light energy each year. The table shows what happens to this energy. kJ used in evaporation of water 523 500 transmitted to the ground 335 000 reflected by the leaves 165 000 used for growth 21 500 used for other life processes 1 500 respiratory heat losses How much energy is used by the grass in photosynthesis?

13. Photosynthesis  →  13.1. Photosynthesis as an energy transfer process

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40

Which process does not involve making nitrogen available to plants?

13. Photosynthesis  →  13.1. Photosynthesis as an energy transfer process

13. Photosynthesis  →  13.2. Investigation of limiting factors

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