Cotton, Gossypium hirsutum, is cultivated for its fibres, which develop inside the fruits after fertilisation, as shown in Fig. 3.1. Fibres taken from cotton fruits are used in the textile industry. Cotton plants have been genetically engineered so that they make a protein poisonous to the caterpillars of several insect pests. This gives the cotton plants resistance to those pests. The cry gene for pest resistance was isolated from the bacterium Bacillus thuringiensis and introduced into cotton plant cells, as shown in Fig. 3.2.
(a(i))[1]
State the name of the enzyme used to cut DNA.
(a(ii))[1]
State the name of the regions marked A in Fig. 3.2.
(a(iii))[3]
Explain how DNA is incorporated into the plasmid.
(b)[4]
Outline how cotton plant cells use the cry gene to synthesise the toxic protein.
(c)[3]
Outline the benefits to farmers of growing genetically engineered cotton plants that contain the toxic protein.
Worked solution & mark scheme
This 12-mark question has a full step-by-step worked solution and mark scheme. One marking point: “restriction endonuclease” …