Biology problem

2.) A line of Drosophila melanogaster with ebony body and sepia eyes (line A) is crossed to a line with tan body and red eyes (line B). The F1 are all tan-bodied, red-eyed, and normal-winged. What proportion of gametes produced by line A have the dominant allele for both loci?_____________ What proportion of the gametes produced by the F1 have the dominant allele for both loci?_____________ An F1 female is crossed to a male from line A. If 1000 offspring were scored for both characters, what number of offspring would be expected to have each of the four phenotypes (assuming no linkage)? List them below. (See attached file for full problem description)

Genetics-Monofactorial (Single gene) Cross with lethal alleles:

4. In mice, the yellow coat color gene (y) is lethal in the homozygous form. YY individuals are brown, Yy individuals are yellow. When two heterozygous individuals are crossed, what would you expect to be the ratio of colors in their surviving offspring? What type of gene interaction is this?

Monofactorial (Single gene) Cross with lethal alleles

4. In mice, the yellow coat color gene (y) is lethal in the homozygous form. YY individuals are brown, Yy individuals are yellow. When two heterozygous individuals are crossed, what would you expect to be the ratio of colors in their surviving offspring? What type of gene interaction is this?

Biology problem

If a man with a red-colorblindness (a sex-linked trait) marries a normal woman, would you expect to see the trait expressed in their children? Diagram the cross below to support your answer:

Genetics questions

1. Duchene muscular dystrophy (DMD) is due to an X-linked recessive gene. A.Explain why 8 to 10 % of female carriers of the DMD gene have muscle weakness. B. A Female carrier of DMD marries a phenotypically normal man. (i) Given the genotypes of the parents using appropriate genetic symbols. Female____ Male_____ (ii) On average what proportion of their male offspring will be affected, and what proportion of their female offspring will be affected with the disorder? 2. Females have been observed with 5 X chromosomes in each somatic cells. How many Barr bodies would such females have? 3. Ichthyosis hystrix gravior ( a greatly thickened-----condition of the skin) is a rare human cond... click for more