Undifferentiated gastrula cells presumed to give rise to neural tissue were transplanted from a donor frog embryo onto an undifferentiated gastrula area of a host frog embryo. The transplantation region in the host was presumed to give rise to epidermal tissue. Both host and donor embryos were allowed to develop following the transplant, and gave rise to two normal embryos. What was the purpose of this experiment

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).

The human body needs energy in order to carry out life processes such as breathing. where does the body get this energy? a. from eating food b. from learning about new things c. from lying in the sun d. from sleeping

Cells a and b are the same size and shape, but cell a is metabolically quiet and cell b is actively consuming oxygen. oxygen will diffuse more quickly into cell because . b the oxygen molecules inside cell b have a higher kinetic energy b. a its membrane transport proteins will not be saturated c. a the diffusion gradient there is shallowerd. b the diffusion gradient there is steeper