5. According to the video, what is the goal of the tree of life? a. To summarize a fossil record
b. To describe how natural selection works
To be a library of all life that has ever lived
d. To explain how all species are related to each other

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.