Astem growing up and out of the soil, away from gravity is an example of a
a. positive tropism
b. negative tropism
c. negative phototropism
d. positive gravitropism

b. negative tropism

Explanation:

A stem growing up and out of the soil, away from gravity is an example of a negative tropism.

well

explanation:

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.