Answer:
The
homologous chromosomes
separate during meiosis I.
This time, the MI results
in two cells, each containing
both genes (1 tan, 1 wild-type); therefore, the genes for spore color have not yet segregated.
Explanation:
Two
homologous chromosomes line up at metaphase I of
meiosis. The two chromatids of one chromosome each
carry the gene for tan spore color (tn) and the two
chromatids of the other chromosome carry the gene
for wild-type spore color (+). The first meiotic
division (MI) results in two cells each containing just
one type of spore color gene (either tan or wild-type).
Therefore, segregation of these genes has occurred
at the first meiotic division (MI). The second meiotic division (MII) results in four cells, each with the
haploid number of chromosomes (lN).
