Review

• A

• B

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• D

Onion plant cells swell but do not burst when placed in distilled water. Which cell component prevents the onion plant cells from bursting?

• A cell membrane

• B cell wall

• C nucleus

• D vacuole

Which diagram shows the appearance of a plant cell several minutes after it has been placed in a concentrated solution of sugar?

• A

• B

• C

• D

• A

• B

• C

• D

Which statement about enzyme-controlled reactions is correct?

• A During the reaction, a substrate changes into a product.

• B The enzyme is slowly broken down during the reaction.

• C The higher the pH the faster the reaction.

• D The product is gradually used up during the reaction.

Increasing temperature above the optimum for the enzyme results in loss of enzyme activity. How is this explained?

• A less frequent collisions between the enzyme and the substrate

• B reduced kinetic energy of the enzyme molecule

• C substrate molecules move faster and effective collisions are less likely

• D the shape of the active site is changed and the substrate will no longer fit into it

What could be a consequence of deforestation?

• A More habitats are produced for animals and plants.

• B More transpiration may increase rainfall.

• C Rainwater runs off the land causing flooding.

• D Soil erosion is less likely.

The diagrams show four types of tissues found in living organisms. Which tissue is involved in contraction?

• A

• B

• C

• D

The diagram shows part of the human gas exchange system.

• A

• B

• C

• D

A piece of blue cobalt(II) chloride paper is clipped to the lower surface of a fresh leaf and is then covered with plastic, as shown. After a few minutes, part of the paper turns pink, showing that water is present.

• A

• B

• C

• D