A recent study of the marine hawksbill turtles' stomach contents revealed that sponges constitute a major portion of their diet. Sponge beds are generally protected from predators by their calcium and silica crystals, but these were found in the turtles' digestive systems. These protective structures are called
A. osculum.
B. spicules.
C. amoebocytes.
D. spongin.
E. choanocytes.
Answer: B
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Suppose a geneticist sequences a specific gene region in two species, A and B, previously known to be closely related. He specifically wants to see which of the two species is closer to an ancestral species
The sequence comparison showed that this region in species B has an extra intron, unlike other near relatives, but that otherwise A and B are virtually the same for this region. Based on this data alone, he could reason that which species was more likely ancestral?
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The parietal lobe is responsible for ____.
A. vision B. sensory input from the skin and joints C. hearing D. generating a motor response E. inhibiting unsuitable behaviors
Commercial inorganic fertilizers have greatly increased agricultural productivity. What is an advantage of using inorganic rather than organic fertilizers?
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