In humans and other mammals, X inactivation takes place:
A. early in development, with each new cell
inheriting the same inactivated X
chromosome as its parent cell.
B. late in development, with each new cell
inheriting the same inactivated X
chromosome as its parent cell.
C. throughout the lifetime of an
organismâ€"with each new cell division, both X
chromosomes are activated, and one is then
inactivated in each new cell.
D. early in development, with all maternal X
chromosomes being inactivated and cells
maintaining active copies of only the paternal
X chromosome.
E. early in development, with all paternal X
chromosomes being inactivated and cells
maintaining active copies of only the maternal
X chromosome.
A
You might also like to view...
Which of the following represents the best definition for microbial death?
A. The organism no longer retains its original shape and structures. B. The organism will not grow on minimal medium. C. The organism will not grow on a medium that normally supports its growth. D. None of these adequately describe microbial death.
Amphistegina gibbosa is a species of protist with filose pseudopodia found near coral reefs. What cannot be true of A. gibbosa?
A. They are enclosed within a shell composed of calcium carbonate. B. They have sacs under the cell membrane. C. They can be useful in studying global warming. D. They are heterotrophic. E. They are closely related to radiolarians.
Monosaccharides and disaccharides are types of ____
a. proteins b. lipids c. nucleic acids d. carbohydrates e. amino acids
Chile's Atacama Desert is used as a model and testing ground for exploration of Mars because ________
a. the ozone layer is functionally absent in both places b. both environments may support bacterial life under the surface of the soil c. temperatures in both environments are quite similar d. neither environment is believed to support life