1. Body temperature regulation is a problem in premature

infants because the (1) is not yet fully functional. Cerebral

palsy involves crippling neuromuscular problems. It usually is

a result of a lack of (2)_ to the infant's brain during deliv-

ery. Normal maturation of the nervous system occurs in a

(3) _direction, and fine control occurs much later than (4)

muscle control. The sympathetic nervous system becomes less

efficient as aging occurs, resulting in an inability to prevent

sudden changes in (5) when abrupt changes in position

are made. The usual cause of decreasing efficiency of the ner-

vous system as a whole is A change in intellect due to

a gradual decrease in oxygen delivery to brain cells is called

(7) Death of brain neurons, which results from a sudden

cessation of oxygen delivery. is called a (8)

Which are evidence of seafloor spreading? check all that apply. molten material magnetic stripes continent material drilled core samples ocean water samples

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).

Why should organisms reproduce more offspring than will survive? select all that apply.