9700 Biology Paper 1

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

• A

• B

• C

• D

A molecule of carbon dioxide is in the centre of a mitochondrion. Assuming there are no other cell structures in its path, how many phospholipid layers will the carbon dioxide molecule have to pass through in order to leave the cell?

• 2

• 3

• 6

• 8

Which polysaccharides contain 1, 4 and 1, 6 glycosidic bonds?

1 amylopectin

2 amylose

3 cellulose

4 glycogen

• 1 and 3

• 1 and 4

• 2 and 3

• 4 only

The flow chart shows some of the steps in the formation of collagen.

Which row correctly identifies X, Y and Z?

• A

• B

• C

• D

What describes the fluid-mosaic model of membrane structure?

• Cholesterol makes the membrane more fluid.

• Fluids can cross the membrane by diffusion or osmosis.

• Proteins act as receptors for cell signalling.

• Proteins and phospholipids move and change places.

Which row correctly describes parts of chromosome structure present during mitosis?

• A

• B

• C

• D

The diagrams show transverse sections through parts of plants. Which of the labelled regions contains cells which are dead?

• A

• B

• C

• D

The diagram shows the distribution of tissues in part of a transverse section through a plant organ.

Which row correctly identifies tissues 1, 2 and 3?

• A

• B

• C

• D

Which description of movement in phloem is correct?

• Adding sucrose to a sieve tube element increases its water potential so that water enters and increases the hydrostatic pressure.

• At a sink, such as a storage organ, sucrose is removed from a sieve tube element and polymerised into starch.

• At a source, such as a photosynthesising leaf, sucrose enters a sieve tube element by facilitated diffusion.

• At a source, sucrose is loaded into a companion cell using a protein that carries both hydrogen ions and sucrose molecules.

Which statements about blood vessels are correct?

1 Collagen fibres in the walls of arteries and veins prevent overstretching.

2 Elastic fibres in large arteries allow stretching during ventricular systole.

3 Smooth muscle in arteries controls the distribution of blood to different parts of the body.

4 Veins have valves because their walls are thin.

• 1, 2, 3 and 4

• 1, 2 and 3 only

• 2 and 4 only

• 3 and 4 only