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1

Which structure is measured in the units shown...

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

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

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2

A student studied two photographs, at the same magnification, of a palisade mesophyll cell, one using a light microscope and the other using an electron microscope. The student observed: the cisternae of the Golgi apparatus the grana in the chloroplasts the two membranes of the nuclear envelope the vacuole enclosed by a tonoplast. Which features can only be seen because of the higher resolution of the electron microscope?

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

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3

A piece of mammalian tissue was homogenised and centrifuged. The biochemical activity of four subcellular fractions was investigated. Which diagram indicates the fraction with maximum synthesis of messenger RNA?

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

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

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4

Which row shows features of a typical eukaryotic cell?

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

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5

Many single-celled animals, living in fresh water, possess vacuoles which contract regularly, expelling excess water. Why do the cells of plants living in fresh water not require such vacuoles?

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

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

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6

Which shows β-glucose?

2. Biological molecules  →  2.2. Carbohydrates and lipids

14. Homeostasis  →  14.1. Homeostasis in mammals

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7

Which row is correct when one molecule of sucrose is hydrolysed?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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8

The formation of glycosidic and peptide bonds is responsible for polymerisation in some biological molecules. Which bonds are found in which molecules?

2. Biological molecules  →  2.2. Carbohydrates and lipids

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9

The diagrams show the structures of two amino acids, each of which has more than one amine (–NH2) group. CH CH2 CH2 CH2 NH C COOH HN NH2 H2N CH CH2 COOH H2N CH2 C O NH2 A peptide bond is formed between the two amino acids. Which groups form the peptide bond?

2. Biological molecules  →  2.3. Proteins

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10

Which explains why haemoglobin is able to carry oxygen?

2. Biological molecules  →  2.3. Proteins

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

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11

Which is correct for a non-competitive inhibitor of enzyme action?

3. Enzymes  →  3.2. Factors that affect enzyme action

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12

The enzyme lysozyme secreted from tear glands forms deposits on contact lenses. Which ingredient would be effective in a contact lens cleaner for removing these deposits?

3. Enzymes  →  3.2. Factors that affect enzyme action

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13

Which is correct for components of a cell surface membrane?

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

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14

A method called freeze-fracture can be used to study the structure of cell membranes. The membrane is frozen and then split down the middle, separating the two layers of phospholipids from each other. Any proteins contained within one layer remain in that layer. Proteins which span the membrane can be found in either layer after freeze-fracture, depending on the protein’s properties. Which statementabout the results of freeze-fracture studies are correct?

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

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15

Which statements are descriptions of both facilitated diffusion and active transport?

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 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 statements about cancer are correct?

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18

The diagram represents the life cycle of a sexually reproducing animal. n n n n 2n 2n 2n Which row correctly identifies meiosis and mitosis?

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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19

The following statements describe events that take place during DNA replication and transcription. Which row is not 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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20

Which statements about complementary base pairing are 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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21

What is the minimum number of base substitutions required to change the nucleotide sequence of the HbA allele to the HbS (sickle cell) allele?

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

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22

Which feature of a plant cell is an adaptation for water uptake from the soil solution?

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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23

A student used a potometer to measure the rate of water loss from a plant by transpiration. The internal diameter of the capillary tube and the distance moved by the bubble in 30 seconds were recorded. The results are shown...

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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24

Which feature of xylem vessel elements helps the cohesion of water?

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

7. Transport in plants  →  7.2. Transport mechanisms

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25

What determines the rate of water movement from the roots to the leaves?

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 photomicrograph shows a transverse section through a leaf. ×50 Which features of a xerophytic leaf are visible in this section?

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

7. Transport in plants  →  7.2. Transport mechanisms

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27

The graph represents data on blood vessels and blood flow. arteries arterioles capillaries venules veins key X Y Z Which row correctly identifies the curves?

8. Transport in mammals  →  8.1. The circulatory system

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28

What occurs during ventricular systole in a mammalian heart?

8. Transport in mammals  →  8.3. The heart

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29

The diagram shows a defect in the walls between the atria. fault in wall of atria What effect would this defect have on the blood circulatory system?

8. Transport in mammals  →  8.3. The heart

8. Transport in mammals  →  8.1. The circulatory system

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30

Which will not be formed in the plasma in capillaries surrounding active tissue?

9. Gas exchange  →  9.1. The gas exchange system

8. Transport in mammals  →  8.1. The circulatory system

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31

Goblet cells are found in the trachea. Which organelles would be found in large numbers in a goblet cell?

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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32

Which tissues are present in a bronchus?

9. Gas exchange  →  9.1. The gas exchange system

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33

Which statements are correct effects of tar in tobacco smoke on the human gas exchange system?

9. Gas exchange  →  9.1. The gas exchange system

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34

The diagram shows the relationship between cholera, measles and TB. Which is correct?

10. Infectious diseases  →  10.1. Infectious diseases

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35

New-born babies have natural passive immunity. What is the correct explanation for this?

11. Immunity  →  11.2. Antibodies and vaccination

11. Immunity  →  11.1. The immune system

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36

Which is a correct description of different types of immunity?

11. Immunity  →  11.2. Antibodies and vaccination

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37

The World Health Organization (WHO) set a target to eradicate polio, using vaccination, by the year 2000. However, cases are still being reported in some parts of the world after this date. What explains these new cases of polio?

11. Immunity  →  11.2. Antibodies and vaccination

10. Infectious diseases  →  10.1. Infectious diseases

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38

The graph shows the annual changes of the following factors in a lake. intensity of light per day numbers of producers numbers of primary consumers quantity of nutrients Which curve represents the numbers of producers?

13. Photosynthesis  →  13.2. Investigation of limiting factors

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39

Which events can occur in the nitrogen cycle?

12. Energy and respiration  →  12.2. Respiration

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

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40

Two different ecosystems of the same size, X and Y, were compared. Both ecosystems have the same climate. The results of the comparison are shown...

18. Classification, biodiversity and conservation  →  18.2. Biodiversity

13. Photosynthesis  →  13.2. Investigation of limiting factors

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