Based on experiments with amphibian embryos, Spemann and Mangold found that
A) transplanted cells always died.
B) transplanted cells completely undifferentiated into random masses of tissue.
C) transplanted cells always formed a whole new embryo.
D) in most cases, transplanted donor cells assumed the developmental fate of the area to which they were transplanted in the host.
E) donor cells maintained their original differentiation no matter where in the host they were transplanted.
D
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You are asked to give a classroom demonstration of DNA supercoiling. To do so, you take two different colored pieces of rubber tubing, twist them very tightly and excessively around each other and join the ends of the tubing appropriately. Next, you relieve the supercoiling by breaking one strand and unwinding it. In this demonstration, the breaking and unwinding to relieve the supercoiling simulates the action of
A. exonucleases. B. polymerases. C. ligases. D. topoisomerases. E. primases. Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? · What key words does the question contain? Gather Content · What do you already know about supercoiling? Consider Possibilities · What other information is related to the question? Which information is most useful? Choose Answer · Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Reflect 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?
How did the rice genome project influence other genome projects?
A. It was the first genome sequenced, so it proved it could be done. B. It sped up the genome analysis of other cereal crops, due to synteny. C. It sped up the analysis of the human genome, since rice has even more genes. D. It helped analysis of all genomes, since it was the basis of the ENCODE algorithms. Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? · What key words does the question contain and what do they mean? Gather Content · What do you already know about the rice genome? Consider Possibilities · Consider the different answer options. Which can you rule out? Choose Answer · Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer? Reflect 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?
The best descriptions of the organelle peroxisomes include
_____ they assist with detoxifying the cell. _____ they have a double membrane around them. _____ their structure includes their own DNA. _____ they produce an enzyme that stops the accumulation of hydrogen peroxide and free radicals.
The membrane that forms a compartment
inside the stroma is the
a. thylakoid. b. mitochondrion. c. lamella. d. plastid. e. tracheid