Plants play a crucial role in the carbon cycle because they
A. do not release carbon dioxide during cellular
respiration.
B. allow carbon to enter an ecosystem through
photosynthesis.
C. have special bacteria that live in their root
systems.
D. are chemically converted into fossil fuels when
burned.

How are viruses and bacteria different?

Abnormal softening of a gland is known as

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).