Biology 3

Question 1

Cells make copies of sections of DNA. These copies then pass out of the nucleus into the cytoplasm. Explain why this happens. (2)

Answer 1

DNA cannot leave the nucleus (1). Protein synthesis occurs in the cytoplasm (1).

Question 2

Explain the function of ATP. (2)

Answer 2

ATP traps energy from respiration (1) and passes it onto other processes which require it (1).

Question 3

Suggest one way that the rate of respiration of an animal can be measured. (1)

Answer 3

Measure the rate of carbon dioxide and oxygen produced (1).

Question 4

Explain why larger, multicellular organisms need to develop special exchange surfaces, e.g. lungs. (2)

Answer 4

They have a smaller SA/V ratio (1) which reduces the movement of substances in and out of cells (1).

Question 5

What is a meristem? (1)

Answer 5

Parts of plants where cells divide (1).

Question 6

Suggest the possible risks of genetically engineering crops. (1)

Answer 6

GM genes could be released into the wild if modified plants breed with wild plants (1). The longterm effects of such crops are unknown (1).

Question 7

What is meant by nuclear transfer? (2)

Answer 7

Putting the nucleus from a body cell (1) into an egg cells with the nucleus removed (1).

Question 8

Suggests how cloning pigs could help solve transplant problems. (2)

Answer 8

Pigs have human genes (1) so organs will not be rejected (1).

Question 9

Describe what is meant by ‘aseptic conditions’ and ‘growth medium’ in cloning of plants. (2)

Answer 9

Without bacteria which can infect plants (1) and in soil rich with hormones and nutrients for plant growth (1).

Question 10

Explain why muscle cells need so many mitochondria. (2)

Answer 10

More energy produced (1) for muscle contractions (1).

Question 11

Why do multicellular organisms require the development of specialised organ systems? (3)

Answer 11

Communication between cells, e.g. nervous system (1)
Supplying cells with nutrients, e.g. circulatory system (1)
Controlling exchanges with the environment, e.g. respiratory system (1)

Question 12

Suggests one harmful side effect of changing the crop potato plant by genetic engineering. (1)

Answer 12

Poisonous (1)
Changes taste (1)
Lower crop yield (1)

Question 13

Why should the average be calculated without value x? (2)

Answer 13

Value x is anomalous (1) which means the average will be inaccurate (1).

Question 14

Write down one way of monitoring sulphur dioxide level in the air. (1)

Answer 14

Lichens - indicator species (1)

Question 15

Explain reasons for rapid evolution. (2)

Answer 15

Lack of predators/competitors (1) and more ecological niches available (1).