Assessing a claim based on context
quick check
news stories have claimed that cell phones may cause cancer or other health problems. others,
including cell phone providers, have indicated that there is no evidence to support the claim of cell
phones causing health problems. which statements would most likely be found in a report issued by a
cell-phone provider? check all that apply.
cell phones emit radio waves, a form of nonionizing radiation
brain tissue is located near where the phone is held and absorbs radiation from the phone.
cell phone use has increased to 303 million subscribers in the us as of 2010
the number and duration of cell phone calls has increased.

Describe two recent or ongoing space missions.

18. over time, how do sand dunes tend to migrate? a. perpendicular to the movement of the wind b. in the same direction as the wind blows c. toward the wind d. in random directions

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).