Answer:

Explanation:
Given -
Total Population - 
Individuals with homozygous HbA/hbA genotype - 
Individuals with homozygous hbs/hbs genotype -
Individuals with heterozygous hba/hbs genotype - 
Let us assume the given population is in Hardy Weinberg' equilibrium
The frequency of individuals in the given population with homozygous HbA/hba genotype is equal to number of individuals with homozygous HbA/hba genotype divided by total population.

The frequency of hba allele is equal to

During the S phase in the cell cycle, the chromosomes are replicated so that there are two copies. These copies are necessary so that each daughter cell created during the M phase will have an identical copy of the DNA.
Therefore, the answer is A: The DNA must be replicated.
The chromosomes joining, cell membrane expanding, and cytoplasm separating all happen during the M phase (mitosis).
Yes it is and it only occurs in women.