A researcher detects an increase in the amount of natural killer cells in a laboratory rat and concludes that ________
A) the rat has, or recently had, a viral infection
B) the rat does not have any cancerous tumors
C) the rat's lymphatic system is not functioning properly
D) the rat's internal innate defenses are weakened
A
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Mechanical receptors can be used to stun or kill prey
Indicate whether the statement is true or false.
Most species of ctenophore are:
a. haploid. b. male or female only. c. hermaphroditic. d. asexual. e. none of the above
Before another action potential “spike” can occur
a. there must be a very brief restoration of the resting conditions in the membrane. b. the membrane voltage must drop to zero. c. the sodium-potassium pump must cease temporarily. d. all of the membrane gates must be closed at the same time. e. all of these must happen.
Why is the sense of smell associated with memories and emotions?
What will be an ideal response?