Answer: Acetyl-CoA
Explanation:
Acetyl-CoA can be obtained from the pyruvate, the end product of aerobic glycolysis. Also, Acetyl-CoA is the one of the starting materials of citric acid cycle.
For lipid synthesis, biotin carries activated CO2 that is incorporated into acetyl-CoA to form Malonyl-CoA, which is then elongated to yield various lipids of different length.
Thus, Acetyl-CoA is the building block of lipid synthesis
It's so small that <span>the microscope does not have such power and magnifying capacity.</span>
Depending on what trait the alleles carry, the brothers will have a different phenotype and a different genotype.
For example; Eye color. My sister is heterozygous, meaning she has brown eyes. I am homozygous recessive, meaning I have blue(green/hazel) eyes. We both have the same parents, I just happened to inherit both of the recessive eye color alleles from my parents whereas, my sister inherited both the dominant and recessive alleles.
So, since the brothers inherited different sets of alleles, their genotype for a certain trait will be different.