The gene encoding for body color in zombie flies is "X-linked". Gray bodies are the wild-type trait and blue bodies are caused by a mutation
- Set up a cross between a male with a blue body and a female who is homozygous dominant for a gray body. Indicate the geno and pheno types of the offspring.
- Set up the reciprocal cross and indicate the genotypes and phenotype of the offspring
Note: Please use wild-type/mutant nomenclature
The female has to be GG, and the male has to be bb. (Cannot be Gb.)
The above are the genotypes. Use a Punnett Square to calculate offspring.
https://www.google.com/search?client=safari&rls=en&q=Punnett+square&ie=UTF-8&oe=UTF-8
To determine the genotypes and phenotypes of the offspring in this scenario, we need to understand the inheritance pattern of the X-linked gene encoding for body color in zombie flies.
In an X-linked inheritance pattern, the genes are located on the X chromosome, and their expression differs between males (XY) and females (XX). Males only have one copy of the X chromosome, so if they inherit the mutant allele, it will be expressed phenotypically. Females, on the other hand, have two copies of the X chromosome, which means they can be homozygous or heterozygous for the gene of interest. In the case of a recessive trait, two copies of the mutant allele are required in females for it to be expressed phenotypically.
Now, let's set up the cross:
1. Cross between a male with a blue body (X^b Y) and a female homozygous dominant for a gray body (X^+ X^+):
Male genotype: X^b Y
Female genotype: X^+ X^+
Male phenotype: Blue body (mutant)
Female phenotype: Gray body (wild-type)
Since the male only has one X chromosome, he can only pass on either X^b or Y to his offspring. The female can only pass on an X^+ to her offspring. The possible genotypes and phenotypes of the offspring are:
Male offspring:
- X^b X^+ (blue body, male)
- Y (non-color related, male)
Female offspring:
- X^+ X^+ (gray body, female)
2. Reciprocal cross:
This time, we will swap the sexes of the parent flies.
Male genotype: X^+ Y
Female genotype: X^+ X^+
Male phenotype: Gray body (wild-type)
Female phenotype: Gray body (wild-type)
Again, the male can only pass on either X^+ or Y, while the female can pass on either X^+ or X^+. The possible genotypes and phenotypes of the offspring are:
Male offspring:
- X^+ X^+ (gray body, male)
- Y (non-color related, male)
Female offspring:
- X^+ X^+ (gray body, female)
- X^+ Y (gray body, female)
Please note that these predictions are based on classical Mendelian genetics and assume no complications such as additional modifying genes or genetic interactions.