Scientists are studying the structure and function of receptor x, a single-polypeptide protein that is found in the membrane around certain types of cells. receptor x contains no alpha-helices or beta sheets. a specific molecule outside the cells is recognized and bound by receptor x. the binding of the molecule to receptor x causes the cells to have a particular response.

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.

not sure but try c two haploid cells

explanation:

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.