Steroid hormones do not require a membrane receptor because they:
a. are small enough to pass directly through pores in the membrane
b. are lipid-soluble and pass through the bilayer
c. pass through special channels
d. are water-soluble
e. dissolve in the cholesterol of the membranes
b
You might also like to view...
During the light reaction water is oxidized to form oxygen. This process
A. yields low-energy electrons. B. yields high-energy electrons. C. is needed to replace the electron lost by P680 during the light reaction. D. yields low-energy electrons and is needed to replace the electron lost by P680 during the light reaction. E. yields high-energy electrons and is needed to replace the electron lost by P680 during the light reaction.
A pollination syndrome is:
A. the synchronous release of pollen by many individuals of wind-pollinated trees B. specializations of plants that attract a specific kind of pollinator C. the simultaneous release of two sperm, one to affect fertilization and the other to initiate formation of endosperm D. a brushlike tongue of hummingbirds to which pollen adheres E. a series of bristles on the backs of insects to which pollen adheres
Which of the following processes does NOT
serve to maintain low pressure at the receiving end of sieve tube pipelines? a. sucrose conversion into cell-wall polysaccharides b. sucrose conversion into starch in the receiving regions c. sucrose conversion to glucose, which is then used in cellular respiration d. activity of companion cells e. conversion of sucrose to fructose in fruits
Which of the following is an example of a mutagen?
A.) repair enzyme B.) triglyceride C.) UV sunlight D.) thymine