chapter 4 questions

Question 1

(c) Most plants produce seeds after fertilisation in sexual reproduction. However, dandelions produce small, windblown seeds without fertilisation taking place. Suggest two advantages to the dandelion of being able to reproduce from these seeds, as well as from pieces of root.

Answer 1

increased no of offspring
dispersal

Question 2

describe amd explain how DNA structure results in accurate replication
4 marks

Answer 2

hydrogen bonds allow strands to separate
2 strands allow for semi conservatuve replication
dna one parent and one new strand
adenine and thymine cytosine and guanine

Question 3

(c) A cancerous tumour is formed by uncontrolled mitotic division. This results in a mass of cells with an inadequate blood supply. Drugs are being developed which only kill cells in a low oxygen environment. Suggest how these drugs could be useful in the treatment of cancer.

Answer 3

cancer cells killed and normal body cells survive
cancer cells low oxygen

Question 4

(c) A cancerous tumour is formed by uncontrolled mitotic division. This results in a mass of cells with an inadequate blood supply. Drugs are being developed which only kill cells in a low oxygen environment. Suggest how these drugs could be useful in the treatment of cancer.

Answer 4

produces haploi cells
maintains diploid number