Which of the following statements about crossing over is true?
a) it occurs only in males.
b) it occurs only in some chromosomes.
c) it occurs only between genes that are heterozygous.
d) it results in reduced genetic variation among gametes.
e) none of the above

E) None of the above

Explanation:

Crossing over happens during meiosis in diploid individuals. Homologous chromosomes (one set that came from an individual's mother and the other set that came from the individual's father) pair during prophase I, and when they are aligned some parts of the homologous chromatids can be exchanged, resulting in recombinant gametes. This increases genetic variation, because the generated gametes are different from any of the original chromosomes the individual had.

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.