Answer:
The answer you are looking for is A.
Mitosis: Asexual reproduction, Four daughter cells, The chromosome's double in number, 46. Two cell divisions, They are identical
Meiosis: Sexual reproduction, Four daughter cells, The chromatid count never changes, Two divisions, They are genetically different from the parent.
Answer:yes
Explanation:
Impure substance is a mixture of 2 or more molecules
One Y and one X chromosome.
Answer:
Because natural selection selects for it. Thus it persists.
Explanation:
You have to understand heterozygote advantage. Basically, it's where heterozygotes have an advantage over homozygotes. In the case of sickle cell disease, heterozygotes have an advantage, and natural selection favors whatever is advantageous. Thus, because heterozygotes each have one recessive sickle-cell allele, as natural selection favors the heterozygotes, the recessive sickle-cell allele persists and remains in the gene pool.
