Answer:its j all of the above
Explanation: because all of them have great sustainabilty
it is D on my point of veiw..
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.
A dichotomous key is defined as a biological tool for identifying unknown organisms to a particular taxonomic level. It is constructed with many levels and series of couplets.
So, by observing the given dichotomous key, it is concluded that the correct answer is Option A- Organism X and Z have at least one observable trait in common in this dichotomous key.