Biology 9700 · AS & A Level · Gene control

Gene control — practice question

Fig. 3.1 shows a sketch of a cross-section through an ovarian follicle.
(a)[4]

State the names of the parts marked A-D in Fig. 3.1.

(b)[4]

Outline the biological basis behind the effect of the oestrogen/progesterone contraceptive pill.

(c(i))[3]

Explain how preventing expression of the gene coding for ZP3 acts as a contraceptive.

(c(ii))[2]

Explain why it is desirable to develop a contraceptive method that does not use oestrogen and progesterone.

(c(iii))[2]

Explain why it is important, when the expression of the gene coding for ZP3 is blocked, that ZP3 is found only in the zona pellucida.

Worked solution & mark scheme

This 15-mark question has a full step-by-step worked solution and mark scheme. One marking point: A - the germinal epithelium

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI