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1

What are the appropriate units for measuring diameters of alveoli, diameters of white blood cells and the width of cell walls?

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

Cells which do not have nucleoli die because they do not have A centrioles and cannot divide. B mitochondria and cannot release energy. C mRNA and cannot transcribe DNA. D ribosomes and cannot synthesise protein.

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

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

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3

What describes the features of an electron microscope?

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

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4

A plan diagram is made of a transverse section of a leaf. Which features should be seen in the diagram?

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

7. Transport in plants  →  7.2. Transport mechanisms

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5

The table shows some of the structural features present or absent in four different cell types. Which identifies the cell type for each column of features?

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

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6

Which types of bonds maintain the tertiary structure of a protein molecule?

2. Biological molecules  →  2.3. Proteins

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7

What is the general formula for starch?

2. Biological molecules  →  2.2. Carbohydrates and lipids

2. Biological molecules  →  2.1. Testing for biological molecules

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8

The hexose sugar molecule in the diagram has its six carbon atoms numbered. C C C C C O CH2OH OH OH OH HO Which carbon atoms join by glycosidic bonds to form amylose and amylopectin?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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9

Which statement about triglycerides is correct?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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10

When a peptide bond is formed, which statement is correct?

2. Biological molecules  →  2.3. Proteins

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11

Which sequence correctly identifies the change in colours during the Benedict’s test?

2. Biological molecules  →  2.1. Testing for biological molecules

3. Enzymes  →  3.1. Mode of action of enzymes

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12

Lactose is a disaccharide present in the milk of mammals. How will a baby mammal benefit from having this sugar, instead of a monosaccharide, in the milk?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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13

When investigating the rate of reaction of the enzyme lipase on the hydrolysis of triglycerides, the pH must be maintained at an optimum to prevent the lipase denaturing. What is the reason for this?

3. Enzymes  →  3.2. Factors that affect enzyme action

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14

Catalase was added to hydrogen peroxide solution. The volume of oxygen produced was measured at intervals. The results are shown...

12. Energy and respiration  →  12.2. Respiration

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

13. Photosynthesis  →  13.2. Investigation of limiting factors

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15

Some viruses are able to bind to the cell surface membrane before entering the host cell. Which sequence of events will lead to a virus invading a cell?

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

Which statement about the fluid mosaic model of membrane structure is correct?

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

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17

Which pair of factors is inversely proportional to the rate of diffusion?

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

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18

For organisms undergoing sexual reproduction, a reduction division occurs before fertilisation. Which reasons explain why this is necessary?

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

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

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19

Colchicine is a chemical that stops chromatids from separating during mitosis. Which phase will the cell reach and then stop dividing?

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

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

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

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20

In the DNA sequence for sickle cell anaemia, adenine replaces thymine in a CTT triplet, forming the triplet CAT. During synthesis of the sickle cell haemoglobin molecule, the amino acid valine is incorporated instead of glutamic acid. What is the anticodon in the transfer RNA molecule carrying this valine?

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

16. Inheritance  →  16.2. The roles of genes in determining the phenotype

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21

Which statements are correct about DNA transcription and translation?

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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22

Bacteria were cultured in a medium containing heavy nitrogen (15N) until all the DNA was labelled. These bacteria were then grown in a medium containing only normal nitrogen (14N) for five generations. The percentage of cells containing 15N in each generation was estimated. Which curve provides evidence that DNA replication is semi-conservative?

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

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

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23

The table shows the sugars and some bases found in RNA and DNA. Which is correct?

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

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

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24

What is transpiration and which advantage does it give to the plant?

7. Transport in plants  →  7.2. Transport mechanisms

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

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25

Which statement explains why the circumference of a tree is less at midday and increases at night?

7. Transport in plants  →  7.2. Transport mechanisms

14. Homeostasis  →  14.2. Homeostasis in plants

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26

Different substances, such as sucrose and amino acids, can move in different directions in the phloem sieve tubes. Which statement explains this?

7. Transport in plants  →  7.2. Transport mechanisms

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27

The photograph shows a type of blood cell. Which statements about these cells are correct?

8. Transport in mammals  →  8.1. The circulatory system

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

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28

When one molecule of oxygen combines with haemoglobin it makes it easier for the next oxygen molecule to bind, which makes it easier for the next molecule of oxygen to bind. Which orders of protein structure change to allow this to happen?

2. Biological molecules  →  2.3. Proteins

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29

The graphs show changes in the percentage saturation of haemoglobin in the blood of humans and of another vertebrate animal. The partial pressure of CO2 remains constant at 1.0 kPa and the temperature is constant at 25 °C. % saturation of haemoglobin with oxygen partial pressure of oxygen human vertebrate X Which conclusion is justified from the graph?

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

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30

Which component of cigarette smoke makes blood platelets more sticky and therefore increases the risk of blood clot formation?

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

8. Transport in mammals  →  8.1. The circulatory system

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31

When a person suffers an asthma attack, the tubes of the gas exchange system narrow and extra mucus is produced. Which of these changes occur during an asthma attack?

9. Gas exchange  →  9.1. The gas exchange system

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32

A person inhales minute particles from a very dusty environment. Which effect will this have on B-lymphocytes and goblet cells?

11. Immunity  →  11.1. The immune system

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

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33

Four ways of being immune are having memory cells after an infection having memory cells after being injected with dead bacteria being injected with antibodies receiving antibodies from breast milk Which row in the table correctly shows the types of immunity?

11. Immunity  →  11.1. The immune system

11. Immunity  →  11.2. Antibodies and vaccination

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34

A graft of tissue, such as skin, from a different person is usually rejected by the body. Which statement about graft rejection is correct?

11. Immunity  →  11.1. The immune system

11. Immunity  →  11.2. Antibodies and vaccination

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35

Which statement about both B- and T-lymphocytes is correct?

11. Immunity  →  11.1. The immune system

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36

Why is it necessary for a person with a bacterial infection to be told to take antibiotics at evenly spaced time intervals?

10. Infectious diseases  →  10.2. Antibiotics

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

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37

How are the diseases cholera, malaria and HIV / AIDS transmitted?

10. Infectious diseases  →  10.1. Infectious diseases

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38

A farmer grows a different crop in a field each year for three years. In the fourth year he grows a leguminous crop, such as clover, and then ploughs this into the soil. The next year he starts the rotation again. How does the fourth year crop add mineral ions to the soil?

7. Transport in plants  →  7.2. Transport mechanisms

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39

At which stage of a food chain of tropical grassland is the energy transfer least efficient?

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

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40

Which soil would have the smallest number of denitrifying bacteria?

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