Biology 9700 · AS & A Level · Natural and artificial selection

Natural and artificial selection — practice question

In plant anthers, meiosis and cytokinesis produce pollen grains. The cells that undergo meiosis are called pollen mother cells. Fig. 2.1 shows five meiosis stages in a pollen mother cell.
(a)[4]

State, using letters J-N in Fig. 2.1, all the stages that show: anaphase; cells containing pairs of homologous chromosomes; crossing over; haploid cells.

(b)[2]

Maize plants have both male and female reproductive organs on the same plant. The male anthers are found on structures called tassels. When selective breeding is used to produce an F1 hybrid, the tassels are removed. Suggest why the tassels are removed when selective breeding is used to produce an F1 hybrid.

(c)[4]

Outline how selective breeding can be used to produce vigorous, uniform maize varieties.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: anaphase is shown by K and M

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