A. Calcium levels will rise, PTH levels will fall, and PTH mRNA levels will fall. B. Calcium levels will rise, PTH levels will rise, and PTH mRNA levels will rise.
C. Calcium levels will fall, PTH levels will fall, and PTH mRNA levels will rise.
D. Calcium levels will fall, PTH levels will rise, and PTH mRNA levels will rise.

humans can cause extinction of a species through overharvesting, pollution, habitat destruction, introduction of invasive species (such as new predators and food competitors), overhunting, and other influences. explosive, unsustainable human population growth is an essential cause of the extinction crisis.

explanation:

i didn't have the answer choices , but i tried my best.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.

it depends on how much it could carry.

(nitrogen fixation) will be your answer sorry if im wrong