Question

(a) What is karyokinesis? Name the four main phases that constitute karyokinesis.

(b) From the phases mentioned in (a) select the phase that is characterized by the following:
(i) The chromosomes arrange themselves upon the equator of the spindle.
(ii) The nucleoli and the nuclear membrane disappear.
(iii) The nucleolus reappears.
(iv) The sister chromatids undergo mutual repulsion and split longitudinally into two halves.
(v) The centrioles divide and move toward the poles.
(vi) Migration of the sister chromatids toward the poles is initiated. [5 MARKS]

Answer 1

a) 2 Marks
b) 3 Marks

(a) Nuclear division in mitosis is called karyokinesis. The four main phases that constitute karyokinesis are as follows:
(i) Prophase (ii) Metaphase (iii) Anaphase (iv) Telophase

(b)
(i) The chromosomes arrange themselves upon the equator of the spindle in metaphase.
(ii) The nucleoli and the nuclear membrane disappear in prophase.
(iii) The nucleolus reappears in telophase.
(iv) The sister chromatids undergo mutual repulsion and split longitudinally into two halves in anaphase.
(v) The centrioles divide and move toward the poles in prophase.
(vi) Migration of the sister chromatids toward the poles is initiated in anaphase.