Question

Distinguish anaphase of mitosis from anaphase I of meiosis.

Answer 1

Anaphase of mitosis : It is the phase of shortest duration. APC (anaphase promoting complex) develops. It degenerates proteins -binding the two chromatids in the region of centromere. As a result, the centromere of each chromosome divides. This converts the two chromatids into daughter chromosomes each being attached to the spindle pole of its side by independent chromosomal fibre. The chromosomes move towards the spindle poles with the centromeres projecting towards the poles and the limbs trailing behind. There is corresponding shortening of chromosome fibres. The two pole-ward moving chromosomes of each type remain attached to each other by interzonal fibres. Ultimately, two groups of chromosomes come to lie at the spindle poles.


Anaphase I of meiosis : Chiasmata disappear completely and the homologous chromosomes separate. The process is called disjunction. The separated chromosomes (univalents) show divergent chromatids and are called dyads. They move towards the spindle poles and ultimately form two groups of haploid chromosomes.

Answer 2

Anaphase begins when each pair of sister chromatids is separated by duplicated centromeres.

Step by step explanation:

Anaphase of mitosis:

• Every chromosome splits the centromere.
• The isolation of the sister chromatids is possible.
• Of each chromosome only one chromatid moves to the pole.
• The chromatids that move to one pole are genetically identical with those that move to the opposite pole.

Anaphase I of meiosis:

• The centromere is not splitting.
• Only Homologous chromosomes are isolated.
• Each homologous pair of chromosomes with both the chromatids move to the pole.
• The chromosomes moving to one pole are not genetically identical to those moving to the opposite pole.