In the mouse, gene B can produce black pigment from a colorless precursor molecule. A mouse having at least one B allele can produce black pigment, whereas the homozygous recessive mouse (bb) cannot and is albino. The agouti locus (A) can convert the black pigment to brown in the presence of at least one dominant A allele, whereas the homozygous recessive (aa) cannot convert the black pigment to brown. What would be the probability of an albino mouse offspring if the parents were genotypes AaBb and AAbb? Group of answer choices 1/16 0 1/4 1/2 3/16

Briefly explain the regulatory interactions between these three classes of patterning genes (gap, pair rule, segment polarity).  What is the temporal order of action and how do the different classes of genes regulate each other?

There are a small number of genes in which the maternal or paternal copy that an organism inherits is methylated. In one case in mice there are known mutations in the gene. If a mouse inherits a mutated gene from its mother, the mouse is normal. However, if the mouse inherits a mutated gene from its father, the mouse is much smaller than normal. Based on this information which allele is normally methylated, the paternal allele or the maternal allele? Explain your reasoning.

Let's consider a paternally imprinted gene. A female skink inherited alleles that that confer: 1) a mutant violet tail-color in the egg and 2) a mutant violet tail-color allele in the sperm. A male skink mate inherited a wild-type blue allele from the sperm and a mutant violet allele from the egg. They have 500 offspring. a. What tail color phenotypes do the parent male and parent female skinks have? Briefly explain your reasoning. female = male = b. What fraction of the offspring do you expect to have each phenotype (blue and violet tail color)? Briefly explain your reasoning/show your work.

Explain why, in humans, chromosomal mutation rates in females are much higher than in males.

What would you predict to be the phenotype of a Drosophila larva whose mother was homozygous for a loss-of-function allele in the nanos gene?

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…

Determine whether the expression of wild type lacZ and lacy would be "inducible," "uninducible" or "constitutive" in examples A and B. A is a haploid genotype and B is a partial diploids. A. lacl-lacO+ lacZ+ lacY- B. A. LacZ: Select] B. LacZ: [Select] lacl-lacO+ lacZ- lacY+ lacl+ lacO+ lacZ-lacY+ ; LacY: [Select ] ; Lac✓ [Select] constitutive inducible uninducible

How do we know that the mutant Bar-eye phenotype in Drosophila is due to a duplicated gene region rather than to a change in the nucleotide sequence of a gene?

In squirrels, individuals that are heterozygous for the mutant LDL receptor gene( Fa) begin to experience heart attacks at the squirrel equivalent of the 30’s and 40’s in humans, while individuals that are homozygous for the mutant LDL receptor allele experience heart attacks much earlier. Closer examination reveals that the hepatocytes of the homozygous normal squirrels contain ONLY normal receptors. In the hepatocytes of the heterozygous squirrels, 50% of the receptors are of the mutant type, and fail to bind the LDL cholesterol, while the other 50% are normal. In individuals homozygous for the mutant LDL receptor allele, only mutant receptors are present.   NAME and DEFINE the genetic phenomenon observed here.