Which causes a drop in female hormone levels?
A. the onset of the menstrual flow
B. if an egg is released from the ovary
C. if the uterine wall thickens
D. if the egg is not fertilized

In the desert, saguaro cacti, owls, horned lizards, and fire ants all share the same space. which of the following can be considered a population? question 9 options: all plants in the same area all cacti in the same area all species in the same area the lizards and the ants