The answer will be A because mitosis usually separate the sister chromatids to sister chromosomes to form two diploid cells. In meiosis, the goal is to have four haploid cells. To form that, cells need to undergo cell division two times. In the case of meiosis I, sister chromatids stay joined together until it reaches meiosis II. Then, the sister chromatids will separate starting at anaphase II in meiosis II. For example, if you start with 92 chromosomes (46 chromatids) during meiosis I, at meiosis II you will have two cells with 46 chromosomes (23 chromatids). By the end of meiosis II, you should form 4 haploid cells that contains 23 chromosomes.
The thermosphere keeps the earth from getting to hot frame the sun and it's the last layer so
the thermosphere
<h2><u>
Full Question:</u></h2>
In the family tree below, people with the recessive trait of attached earlobes are shaded gray.
What must be true about the person labeled "A"?
A. It is a male with at least one dominant allele.
B. It is a male with two dominant alleles.
C. It is a female with at least one dominant allele.
D. It is a female with two dominant alleles.
<h2><u>Answer:</u></h2>
Its a male with atleast one dominant allele.
Option A.
<h3><u>Explanation:</u></h3>
The gene for the attached earlobe is recessive while the gene for the free earlobes is dominant. In the phylogenetic tree, we can see that both the father and mother aren't having attached earlobes. So both of them are having atleast one dominant allele which makes them have free earlobe.
In the F1 offsprings, one of the female and a male is having free earlobes. So both of them have atleast one dominant allele. The 2nd female is having an attached earlobe. So both the recessive allele have come form one parent each. So both of them are heterozygous.
Thus, the male marked as A atleast have one dominant allele. He can be a homozygous dominant, but the probability is 25%.