Match the following. Match the items in the left column to the items in the right column. a galaxy with a central bulge,
1. black hole
2. elliptical galaxy
3. galaxy
flattened disk, and curving arms
a region of space with matter so
dense that light cannot escape it
a galaxy whose stars are
symmetrically dispersed in a spherical or
elongated shape
a galaxy formed by the collision of
other galaxies
a large-scale collection of stars,
dust, and gas held together by gravity
4. irregular galaxy
5. Spiral galaxy

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).