Question

1. the drawing below has been made from a photograph showing a cell undergoing mitosis. based on the drawing, in what stage of mitosis must the cell have been in? 6. the drawings a - e show stages of mitosis in an plant cell. (a) which of the drawings a - e shows (i) interphase (dna is replicated) (ii) prophase (chromosomes - 2 sister chromatids - shorten) (iii) metaphase (sister chromatids line up) (iv) anaphase (sister chromatids separate) (v) telophase (new nucleus forms at each end) (vi) cytokinesis (cell contents divided between 2 daughter cells) (b) give two processes which occur during interphase and which are necessary for mitosis to take place.

Explanation:

(a) (i) In interphase, DNA replication occurs and the cell prepares for division. Drawing C shows a cell with a visible nucleus and un - condensed chromatin, typical of interphase.
(ii) In prophase, chromosomes condense and become visible as two sister chromatids. Drawing B shows condensed chromosomes.
(iii) In metaphase, sister chromatids line up at the equator of the cell. Drawing E shows chromosomes aligned in the middle.
(iv) In anaphase, sister chromatids separate and move towards opposite poles. Drawing A shows separated chromatids moving apart.
(v) In telophase, new nuclei form at each end of the cell. Drawing D shows the formation of two new nuclei.
(vi) Cytokinesis is the division of the cell contents between two daughter cells, which also occurs in drawing D as the cell starts to divide.
(b) During interphase, DNA replication is crucial to ensure each daughter cell has a complete set of genetic material. Also, cell growth occurs to increase the cell's size and organelle number to support division.

Answer:

(a) (i) C
(ii) B
(iii) E
(iv) A
(v) D
(vi) D
(b) DNA replication, cell growth