PLEASE HELP ASAP!!! 13. Populations of organisms grow at an rate, but factors such as food, habitat, predators, weather, disease, climate, & temperature can affect the maximum population size an area can support.

14. Sea otters are an example of a species where the effects of overhunting this population of organisms will severely affect the population #s of other species.

15. is determined by the # of species in a specific area as well as the # of different kinds of species in a specific area.

Choose the incorrect statement (a) the motor end plate membrane is only capable of generating graded potentials, but it is contiguous with the skeletal muscle sarcolemma, which can generate action potentials. (b) propagation of an action potential through the t-tubules into the sarcoplasmic reticulum triggers the release of ca++ into the cytoplasm of a skeletal muscle fiber. (c) the generation of suprathreshold endplate potentials in multiple muscle fibers could be due to the increased frequency of action potential generation at the axon hillock of a single motor neuron. (d) a greater amount of ach would be found in the presynaptic vesicles of a motor unit that fired several action potentials after exposure to botulinum toxin, than in a motor unit that fired several action potentials after exposure to the venom of the krait snake (which contains α-bungarotoxin).