The germ layers are formed in which of the
following stages?
a. cleavage
b. meiosis
c. gastrulation
d. zygote formation
e. blastula formation
C
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Electrons move between PSII and PSI via __________
A. cytochrome b6f B. water C. chlorophyll D. NADP+ E. NADPH
Your roommate takes up smoking, and you hate it. Use what you know about nicotine to convince her to quit. (Check all statements that are true.)
_____ Nicotine binds to a receptor in the brain that normally receives acetylcholine. _____ Nicotine evolved to protect the tobacco plant by killing grazing cattle. _____ The brain adapts to smoking by changing the levels of this receptor. Over time, more drug is required to get the same effect. _____ Nicotine is not addictive, but is still very dangerous. _____ Nicotine is identical to an endogenous ligand in the human body. _____ Nicotine evolved to protect the tobacco plant by killing insects. Clarify Question · What is the key concept addressed by the question? · What type of thinking is required? Gather Content/Choose Answer · What do you already know about nicotine? What other information is related to the question? 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?
In prophase, ribosomal RNA synthesis stops when the chromosomes condense, and as a result:
A. the chromosomes line up at the equator of the cell. B. the nuclear envelope reforms. C. the nucleolus disappears. D. the chromosomes lengthen.
Natural selection changes allele frequencies in populations because some __________ survive and reproduce more successfully than others.
A) alleles B) loci C) gene pools D) species E) individuals