The most likely explanation for why toothed whales have a blowhole is
A. they evolved from an animal with gills.
B. blowholes are vestigial structures passed down from the first marine vertebrates.
C. blowholes are more efficient for breathing underwater than gills are.
D. blowholes are more efficient for large animals.
E. they evolved from an animal with nostrils.
Answer: E
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Which of the following statements about mRNAs and microRNAs is false?
A. Both are transcribed by RNA Pol II. B. Both are capped and polyadenylated. C. Both undergo nucleolytic cleavage in the nucleus and the cytoplasm. D. Both are processed via interaction with snoRNPs.
Which of the following structures gives rise to endosperm?
a. zygote formed from the fusion of a sperm and an egg b. triploid cell formed during double fertilization c. inner wall of the ovary d. cytoplasm of the megaspore e. cytoplasm of the microspore
Chlorophyll b absorbs green wavelengths of light that chlorophyll a cannot absorb. In this respect, chlorophyll b acts as
A. an energizer for photosynthetic bacteria. B. a light absorber in the green light. C. a more efficient pigment. D. an accessory pigment.
Genealogical species are groups that have diverged from a common ancestor but aren't yet reproductively ________
Fill in the blank(s) with correct word