The answer is D) <span>Calculate the probability of a child having either sickle-cell anemia or cystic fibrosis if parents are each heterozygous for both.
The addition rule is used to calculate the probability of one of the events from multiple pathways. If you want that only one of the events happens, you will use the addition rule. In a case when you want to calculate the possibility of a child having EITHER sickle-cell anemia OR cystic fibrosis, you will use THE ADDITION RULE.
For example, in statement B) you will not use this rule because there is no either/or, but both/and. In case, B) you would use the multiplication rule.</span>
The answer is B. This is called genetic shift. The pups with
advantageous traits are able to survive until the age of reproduction hence able
to pass their genes to the next generation. Few and fewer pups with disadvantageous
traits will get to reproduce hence the allelic frequencies of the shark population
will shift in favour of increased hunting efficiency.
They are called as Fossils. Hope it helped you. Please mark as the brainliest answer if it helped.
The answe to your question is the first choice which is letter A. Loamy.
