Biology 9700 · AS & A Level · Passage of information from parents to offspring

Passage of information from parents to offspring — practice question

Spermatogenesis, which is the formation of male gametes, takes place in the testes of a male starting at puberty. Fig. 3.1 presents the order of events during spermatogenesis.
(a(i))[1]

Using Fig. 3.1, state what cells are doing in process B.

(a(ii))[1]

Using Fig. 3.1, say what is occurring in the cells during process D.

(a(iii))[1]

Using Fig. 3.1, state what is occurring in the cells during process F.

(b)[4]

Female gametes develop within follicles. Fig. 3.2 shows a section through a mature (Graafian) follicle in a human ovary. Table 3.1 below gives several statements about the mature follicle. Each statement is matched to one of the letters G, H, J and K shown in Fig. 3.2. Fill in the table using the letters G, H, J and K.

(c)[5]

A man and a woman can be classed as infertile if conception has not occurred after 12 months of trying. They may choose in-vitro fertilisation (IVF) if the woman is producing some normal eggs. Outline the technique of IVF.

(d)[2]

Not every pregnancy resulting from IVF ends in a live birth. In the USA in 2008 the data were: 85% of these pregnancies resulted in live births for women under 35 years old; 66% of these pregnancies resulted in live births for women aged 38-40 years old. Suggest reasons for the difference in percentage for the two groups of women.

Worked solution & mark scheme

This 14-mark question has a full step-by-step worked solution and mark scheme. One marking point: mitosis / rise in number of cells

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