Open QuestionHow many Barr bodies are found in a normal human female nucleus? In a normal male nucleus?
Open QuestionAn insect species is discovered in which the heterogametic sex is unknown. An X-linked recessive mutation for reduced wing (rw) is discovered. Contrast the F₁ and F₂ generations from a cross between a female with reduced wings and a male with normal-sized wings when the female is the heterogametic sex.
Open QuestionAn insect species is discovered in which the heterogametic sex is unknown. An X-linked recessive mutation for reduced wing (rw) is discovered. Contrast the F₁ and F₂ generations from a cross between a female with reduced wings and a male with normal-sized wings when the male is the heterogametic sex.
Open QuestionConsider the case where a mutation occurs that disrupts translation in a single human mitochondrion found in the oocyte participating in fertilization. What is the likely impact of this mutation on the offspring arising from this oocyte?
Open QuestionIt has been suggested that any male-determining genes contained on the Y chromosome in humans cannot be located in the limited region that synapses with the X chromosome during meiosis. What might be the outcome if such genes were located in this region?
Open QuestionPredict the potential effect of the Lyon hypothesis on the retina of a human female heterozygous for the X-linked red-green color blindness trait.
Open QuestionCat breeders are aware that kittens expressing the X-linked calico coat pattern and tortoiseshell pattern are almost invariably females. Why are they certain of this?
Open QuestionIn mice, the Sry gene (see Section 7.2) is located on the Y chromosome very close to one of the pseudoautosomal regions that pairs with the X chromosome during male meiosis. Given this information, propose a model to explain the generation of unusual males who have two X chromosomes (with an Sry-containing piece of the Y chromosome attached to one X chromosome).