Occasionally during meiosis, a mistake can happen whereby a gametemay receive zero or two sex chromosomes rather than one. Bridgesmade a cross between white-eyed female flies and red-eyed male flies.As you would expect, most of the offspring were red-eyed femalesand white-eyed males. On rare occasions, however, he found a whiteeyed female or a red-eyed male. These rare flies were not due to newgene mutations, but instead were due to mistakes during meiosis inthe parent flies. Consider the mechanism of sex determination in fruitflies and propose how this could happen. In your answer, describe thesex chromosome composition of the rare flies

XX individuals can be sex-reversed males if one of their X chromosomes contains a translocated portion of the Y chromosome that includes the SRY gene. In light of what you now know about X-chromosome inactivation, it seems that this karyotype might have more complex consequences. In fact, although most such males are completely sex-reversed, X-chromosome inactivation can cause some of these XX males to have varying degrees of residual female characteristics. a. X-chromosome inactivation in normal XX embryos occurs earlier in development than SRY production in normal XY embryos. When present on a translocation X chromosome, SRY is subject to inactivation. Formulate a hypothesis to explain why many XX individuals with a translocation X chromosome that includes the SRY gene are not completely sex-reversed (male). b. Based on your answer to part (a), why do you think some individuals with this karyotype are completely sex-reversed?

When the cloned cat Carbon Copy (CC) was born , she had black patches and white patches, but completely lacked any orange patches. The knowledgeablestudents of genetics were not surprised at this outcome.Starting with the somatic ovarian cell used as the sourceof the nucleus in the cloning process, explain how this outcomeoccurred.

Part A You start your experiments with the eyeless mutation on chromosome IV. You cross the reciprocal translocation strain to the eyeless pure line to generate F, flies that are both translocation heterozygotes and Ee heterozygotes. You decide to testcross F, males and females in two separate experiments to take advantage of the fact that crossing over does not occur in male Drosophila. F, males x pure eyeless females (Note: There is no crossing over F, females x pure eyeless males (Note: Crossing over in the F, males.) Cross may occur in the F, females.) 4 eyeless, fully fertile 4 wild-type, semi-sterile 4 eyeless, semi-sterile 4 wild-type, fully fertile 4 eyeless, fully fertile 4 wild-type, semi-sterile 4 eyeless, semi-sterile 4 wild-type, fully fertile F, Progeny What can you conclude from these results? Select the two correct statements. > View Available Hint(s) O The F2 progeny in both experiments contain recombinants. O The F2 progeny contain recombinants only when F, females…

Cystic fibrosis is a recessive disease that affects many parts of the body, but primarily presents itself through difficulty breathing and through cysts in the pancreas. It is caused by mutations in the gene CFTR. What chromosome is the gene on?