The bicoid gene is a coordinate maternal-effect gene.
A ...

Question

The bicoid gene is a coordinate maternal-effect gene.

A female Drosophila heterozygous for a loss-of-function bicoid allele is mated to a male that is heterozygous for the same allele. What are the phenotypes of their progeny?

Accepted Answer

Hey, everyone. Let's take a look at this question together which of the following statements correctly describes the expected phenotypes of progeny resulting from mating. A female Drosophila, heterozygous or a loss of function bio allele with a male that is homozygous for this allele. Is it answer choice. A al progeny will have the wild type phenotype. Answer choice. B all progeny will have the bio mutant phenotype. Answer choice. C 25% of progeny will have the wild type phenotype. 50% will have the heterozygous brod phenotype and 25% will have the homozygous bio phenotype or answer choice. D 50% of progeny will have the wild type phenotype and 50% will have the heterozygous bio phenotype. Let's work this problem out together to try to figure out what the expected phenotypes of the progeny are from this cross. So we have a female Drosophila that is heterozygous or that loss of function B coid allele. And we also have a male who is homozygous for that allele. So we have our female and we have our male and since the female is heterozygous for that loss of function bio allele, we will attach that B coid allele to one of the two all for the female. And the male is homozygous for the ale. So the male will have two of those bio alleles. And since we want to know the phenotypes of their progeny, we have to set up a pun square in order to cross to parents to determine the expected outcome of their progeny. So on the top of our puit square, we will have the genotype of the female. And on the left side of the punt square, we will have the genotype of the male. And we can go ahead and do our pundit square cross to determine the outcome of their progeny and figure out what the expected phenotypes are for that progeny. And from the pundit square, we are able to see that we have 50% of the progeny are heterozygous. So we have 50% our heterozygous having only one of the bit coid all. And we have 50% that are homozygous or that bio allele since they have two copies of the bio allele and the homozygous for the allele is the wild type phenotype. So that means that 50% of the progeny will have the wild type phenotype and 50% will have the heterozygous bio phenotype. So answer choice, d 50% of the project will have the wild type phenotype and 50% will have the heterozygous bio phenotype is the correct answer since we have our female parent that is heterozygous for that loss of function byod allele. And we have the male who is homozygous for the allele. And we set up that square to determine the expected phenotypes of their progeny, which is 50% having that heterozygous bi code phenotype and 50% having the wild type phenotype, which is answer choice d the correct answer. I hope you found this video to be helpful. Thank you and goodbye.

The bicoid gene is a coordinate maternal-effect gene.
A female Drosophila heterozygous for a loss-of-function bicoid allele is mated to a male that is heterozygous for the same allele. What are the phenotypes of their progeny?

Key Concepts

Bicoid Gene Function

Maternal Effect Genes

Genotype and Phenotype Relationship

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