Question

If you have non sister chromatids bearing alleles Aa, when will they separate?

Answer 1

Non sister chromatids bearing alleles Aa separate at anaphase -II and not at anaphase- I.

Explanation:

Meiosis occurs in 2stages, i.e. meiosis-I and meiosis-II.

Pairing of homologous chromosomes bearing alleles AA and aa occurs. Crossing over occurs during metaphase-I and two homologous chromosomes bearing alleles Aa separate at anaphase-I.

Two daughter cells formed at the end of meiosis-I, have one bivalent each. Each bivalent has two chromatids bearing Aa alleles.

These two chromatids of each bivalent separate atanaphase-II.

4 daughter haploid cells are formed at the end of meiosis -II. Two of the cells will have one chromatid each bearing A allele and 2 cells will have one chromatid each having aa allele.

Thus the separation of two alleles Aa occurs at anaphase-II and not at anaphase-I