1. Examining the two cubes in your kit: Table 1
Dice
Dimensions Surface Area
(cubes) (Length, width, # of sides x
and height) length x width
Volume
Length x width
x height
Ratio
(surface area/
volume)
Example:
Cube = 3 mm
length = 3 mm
width = 3 mm
height = 3 mm
6 sides x 3 x 3 =
54 mm?
3x3x3 =
27 mm
54/27 (Divide
the surface area
by the volume.
The ratio is that
number over 1.)
2/1 ratio
Small dice
5 mm
Large dice
16 mm

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).