Biology 9700 · AS & A Level · Structure of nucleic acids and replication of DNA

Structure of nucleic acids and replication of DNA — practice question

The photomicrographs in Fig. 3.1 display stages of the mitotic cell cycle in the root tip of the onion, $Allium\ sp$. They are all shown at identical magnification. Stages A to C are in the correct order, whereas stages K to N are not in the correct order.
(a)[1]

Name stage A and stage C.

(b)[1]

Place stages K to N into the correct sequence, beginning with the stage that comes immediately after stage C.

(c)[3]

Explain how the movement of the chromosomes and spindle during stage L in Fig. 3.1 ensures that the two daughter cells are genetically identical.

Worked solution & mark scheme

This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: A = interphase and C = metaphase (both are needed)

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