Scientists unearth a Wooly Mammoth from the Siberian Ice Sheath and discover that a eukaryotic "amoeba"-like cell is still alive. Which component of the cell membrane might contribute to maintaining the fluidity of plasma membranes under freezing conditions?
A. high levels of saturated phospholipid tails within the lipid bilayer
B. high levels of long phospholipid tails within the lipid bilayer
C. absence of cholesterol
D. high levels of unsaturated phospholipid tails within the lipid bilayer
E. peripheral proteins
Answer: D
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In its youth, a pet parrot was owned by someone who kept the wings clipped and never allowed it to fly. Later in life, the new owner let the feathers grow and let the parrot fly around the house. But the parrot kept knocking over lamps and crashing into walls. "Wow," said the owner, "I guess parrots are just too clumsy to fly around a house without destroying everything." What is an alternative explanation?
A. In nature, parrots have much more room to fly, and do not have to navigate around delicate home decor. B. Since the parrot was not able to practice flying during the critical period for flight development, the brain circuits for accurate flying were not able to develop. C. The parrot just needs more practice flying -- although it did not get to fly when young, this should not affect later ability. D. The critical period for flying development in the brain has just now begun with the bird's first attempt. In a few weeks the critical period will end, so it must practice during this time. Clarify question: What is the key concept addressed by the question? What type of thinking is required? Gather Content: What do you already know about behaviors in an adult parrot based on how it was raised? What other information is related to the question? Choose Answer: Given what you now know, what information is most likely to produce the correct answer? Reflection on Process: Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
Imagine an invertebrate that lives in an estuary where salinity varies cyclically with the tides. If this animal practices homeostasis with respect to the salt concentration of its body fluids, its salt concentration will show ________
A) no fluctuations B) slight, continuous fluctuations C) a more concentrated state than the surrounding water at all times D a more diluted state than the surrounding water at all times
The transfer of a phosphate group to a molecule or compound is called
A) carboxylation. B) ionization. C) phosphorylation. D) hydrogenation.
Sequences of DNA assembled by identifying overlaps among smaller DNA segments are known as
A. a contig. B. draft sequences. C. single strand polymorphisms. D. the proteome. E. synteny.