Many endangered species are predators that belong to the higher trophic levels. which in the process the primarily affects animals at the highest trophic levels?

Eutrophication would be your answer .

the answer is biomagnification

b.

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.