2nd choice is the correct one
Helper T cells <span>are required for almost all </span>adaptive immune responses<span>. They not only help activate B </span>cells to<span> secrete antibodies and macrophages </span>to<span> destroy ingested microbes, but they also help activate cytotoxic </span>T cells to<span> kill infected target </span>cells<span>.</span>
Answer:
The correct answer would be option D.
Explanation:
True breeding is a breeding procedure in which the parents would always produce their progeny with the same phenotype characters as the parents carry. This means for every trait these parents are homozygous so their offspring must show a similar phenotype.
In this case, all cattle are true-breeding which means they homozygous alleles show the progeny will also show similar traits which are short stature with brown hides and short horns.
Thus, the correct answer is option D.
The answer is A. Being a liquid at room temperature, surface tension, and that ice floats.