What is the chemical composition of the rod pigment, rhodopsin, and how does it appear to act in the reception of light?
What will be an ideal response?
Rhodopsin is a combination of retinal and scotopsin. Retinal is chemically related to vitamin A and is synthesized from it. Retinal can form a variety of three-dimensional forms called isomers. The opsin protein combines with the 11-cis retinal to form rhodopsin. The light-triggered changes in retinal cause hyperpolarization of the rods. This happens because the light turns off sodium entry, which then inhibits the release of neurotransmitter, thus turning off electrical signals.
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Spermatogenesis
a. occurs in the epididymis b. begins with a spermatozoan c. is controlled by both testosterone and FSH d. has all of the above characteristics e. has none of the above characteristics
When the pH of the extracellular fluid drops, the kidneys
A) excrete more hydrogen ions. B) excrete more bicarbonate ions. C) reabsorb bicarbonate ions. D) excrete more hydrogen ions and excrete more bicarbonate ions. E) excrete more hydrogen ions and reabsorb bicarbonate ions.
During your last visit to the doctor, your blood pressure was 125/80. Calculate your pulse pressure
A) 45 B) 205 C) 10,000 D) 1.56
The continuation of the peritoneum that binds the small intestine and suspends it from the abdominal wall is called the ________
A) mesentery B) mesocolon C) mediastinum D) greater omentum E) lesser omentum