Until recently, acquired immunity was thought to only occur in jawed vertebrates. Which of the following observations suggest that this is NOT the case?
a. Phenoloxidase activity enables hemocytes to form an impermeable wall of melanin around an infecting pathogen.
b. Invertebrate immune cells secrete an IL-1 like compound.
c. Invertebrates produce lectins, which coat bacterial cells, priming them for phagocytosis.
d. Copepods become resistant to tapeworms after an initial exposure.
e. None of these.
D
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Clenching the fingers to make a fist, then relaxing and straightening them is an example of ________ followed by ________.
A. extension; hyperextension B. abduction; adduction C. extension; flexion D. adduction; abduction E. flexion; extension
The corpus luteum is a gland that
A. secretes progesterone. B. forms from a mature follicle after ovulation. C. Both "forms from a mature follicle after ovulation" and "secretes mainly progesterone" are correct. D. releases the secondary oocyte. E. degenerates into a zygote if pregnancy does not occur.
Amphetamines produce a state of increased alertness and wakefulness by increasing the release and blocking the reuptake of what neurotransmitter?
A) acetylcholine B) glycine C) norepinephrine D) serotonin
From outermost to innermost layers, the wall of the eye consists of these three layers
A) vascular, fibrous, sensory B) fibrous, sensory, vascular C) sensory, vascular, fibrous D) fibrous, vascular, sensory