The obvious advantage of the lactose operon system is that
a. lactose is not needed as energy for bacteria.
b. lactose-metabolizing enzymes need not be made when lactose is not present.
c. the bacteria will make lactose only in the presence of the proper enzymes.
d. milk is not needed for the adult human diet.
e. glucose can substitute for lactose in the diet of intolerant persons.
b
You might also like to view...
The evolution of eukaryotic cells most likely involved _____
A) endosymbiosis of an aerobic bacterium in a larger host cellâ€"the endosymbiont evolved into mitochondria B) anaerobic archaea taking up residence inside a larger bacterial host cell to escape toxic oxygenâ€"the anaerobic bacterium evolved into chloroplasts C) an endosymbiotic fungal cell evalving into the nucleus D) acquisition of an endomembrane system and subsequent evolution of mitochondria from a portion of the Golgi
Amino acids, the monomer units comprising proteins, contain two functional groups, amino and carboxyl
Indicate whether the statement is true or false.
The calyx is composed of
a. petals. b. sepals. c. stigmas. d. ovules. e. anthers.
Select all of the following that are postzygotic isolating mechanisms.
A. Hybrids develop abnormally. B. Hybrids cannot be formed. C. Hybrids fail to become established in nature. D. Hybrids are sterile.