Question

to transduce a signal, visual pigments will activate____, which will bond to phosphodiesterase
options: camp, ach, adenylate cyclase, the g protein
question 22
medial fibers from each eye will cross at the
options: mammillary gland

Explanation:

First Question (Signal Transduction in Vision)

In visual signal transduction, visual pigments (like rhodopsin) activate the G - protein (transducin). cAMP is involved in other signaling pathways, Ach (acetylcholine) is a neurotransmitter, and adenylate cyclase is involved in cAMP production but not directly activated by visual pigments for this pathway. So the correct option is the one related to the G - protein activation.

Medial (nasal) fibers of the optic nerve from each eye cross at the optic chiasm. The mammillary gland is related to the limbic system and not optic fiber crossing.

Answer:

D. the G protein (assuming the options are labeled A to D with D being "the G protein")

Second Question (Medial Fibers Crossing)

(Note: The options seem to be cut off, but typically, medial fibers of the optic nerve cross at the optic chiasm. If the intended correct option was related to the optic chiasm, and assuming the options had that, but based on the visible part, if we assume the correct option related to the optic chiasm was among the choices, but since the options are not fully visible, we can only note the concept. However, if we assume the options included "optic chiasm" (even if not fully shown), that would be the answer. But with the given partial options, we can state the biological fact: medial fibers from each eye cross at the optic chiasm. )