musudimasitsa

A geneticist discovers an obese mouse in his laboratory colony. He breeds this obese mouse with a normal mouse. All the F1 mice from this cross are normal in size. When he interbreeds two F1 mice, eight of the F2 mice are normal in size and two are obese. The geneticist then intercrosses two of his obese mice, and he finds that all of the progeny from this cross are obese. These results lead the geneticist to conclude that obesity in mice results from a recessive allele. A second geneticist at a different university also discovers an obese mouse in her laboratory colony. She carries out the same crosses as the first geneticist and obtains the same results. She also concludes that obesity in mice results from a recessive allele. One day, the two geneticists meet at a genetics conference, learn of each other's experiments, and decide to exchange mice. They both find that, when they cross two obese mice from the different laboratories, all the offspring are normal. However, when they cross two obese mice from the same laboratory, all the offspring are obese. Which of the following BEST explains their results?

Is any hydrogen containing substance that is capable of donating a proton to another?

Two genes combine to generate the phenotype of the comb of a rooster. The 4 possible phenotypes are walnut, rose, pea and single. Rose has an absolute requirement for the presence of the dominant allele R and pea has an absolute requirement for the presence of the dominant allele P. Some of the chickens below may carry the corresponding recessive alleles r and p in the heterozygous or homozygous from (the somatic cells of chickens are diploid). A walnut comb rooster is mated to three hens. Hen A is a walnut comb and has offspring in the ratio of 3 walnut to 1 rose. Hen B is a pea comb and has offspring in the ratio 3 walnut, 3 pea, 1 rose and 1 single comb. Hen C is a walnut comb and has only walnut comb offspring. What are the genotypes of the rooster and the 3 hens? The answers are Rooster = RrPp ; Hen A = RRPp; Hen B = rrPp; Hen C = RRPP.I just can't see how these answers came about. Any help will be truly appreciated.

1. In chickens, congenital baldness results from a Z-linkedrecessive gene. A bald rooster is mated with a normal hen. The F1from this cross are interbred to produce the F2. What proportion ofthe F2 offspring is expected to be normal hens?

   		a. 1?4
   		b. 1?2
   		c. 3?4
   		d. All of the offspring

What made Gravity?