The G1-to-S checkpoint, one of the cyclins has reached a concentration great enough to complex with one of the CDKs to initiate DNA synthesis. Which cyclin and which CDK are the ones involved?
a. cyclin G1/S and CDK2
b. cyclin G1/S and CDK1
c. cyclin S and CDK2
d. cyclin S and CDK1
Ans: a. cyclin G1/S and CDK2
You might also like to view...
What does the term biogenesis mean?
A. Formation of life from nonliving chemicals B. Formation of self-replicating molecules C. Formation of chemicals from organic monomers D. Formation of life from preexisting cells
Infections by Helicobacter pylori cause 90% of peptic ulcers in the United States. These bacteria have pili that are only expressed in acidic conditions. A characteristic of this organism should be an ability to
A. avoid ingestion by cells in the immune system. B. enter the bloodstream. C. attach to cells in the host organism's stomach. D. induce a large antibody response. E. move in the direction opposite the pili.
Four of the five answers listed below are
characteristics of ethylene. Select the EXCEPTION.
a. a source is aging plant tissues b. promotes fruit ripening c. triggers cells division d. is a gas e. inhibits cell elongation
The biological species concept by Ernst Mayr defines a species in the textbook as a group of interbreeding natural populations reproductively isolated from other such groups. However, such a definition cannot be used for
A. fossils. B. asexual organisms. C. determining species based on dead or preserved specimens. D. organisms that cannot be raised in captivity, easily bred, or with very long generation times. E. All of the situations pose problems for the biological species concept.