The methylation state of an individual CpG island:
A. is fixed; such genes are permanently
turned off.
B. is fixed, but this has no effect on whether
genes are expressed.
C. is randomâ€"sometimes the cytosines are
methylated and sometimes they're not, but
the state is independent of the environment
or cell type.
D. can change over time in response to
environmental cues, allowing genes to be
turned on or off as needed.
E. can change over time in response to
environmental cues, but this has no effect on
gene expression.
D
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What statement best summarizes the nature of scientific inquiry? a. Explanations about nature must be testable in ways that others can repeat
b. Once experimentally verified, scientific hypothesis becomes scientific fact. c. Moral, philosophical, and ethical values will eventually be replaced by rational explanations. d. Personal experience, insight, and revelation are as valid as experimental data.
Molecular/structural orientations (gradients) in an egg are thought to play a significant role in development. What is the origin of such gradients? What evidence indicates that the maternal genotype is involved in providing such gradients?
What will be an ideal response?
In New York, when would the warmest days of the year usually occur?
A) around the summer solstice B) about one month after the summer solstice C) about one month before the summer solstice D) in mid-September
Terminally differentiated cells such as neurons are in the phase of the cell cycle known as ________
Fill in the blank with correct word.