An attached-X female fly, XXY (see the Insights and Solutions box), expresses the recessive X-linked white-eye phenotype. It is crossed to a male fly that expresses the X-linked recessive miniature wing phenotype. Determine the outcome of this cross in terms of sex, eye color, and wing size of the offspring.

Short Answer

Expert verified
Short Answer: When an attached-X female fly with white eyes (X^w X^w Y) is crossed with a male fly with miniature wings (X^m Y), the offspring will have the following genotypes and phenotypes: Females: - 50% with Wild-type eyes and Miniature wings (genotype X^w X^m). Males: - 50% with White eyes and Wild-type wings (genotype X^w Y). - 50% with Wild-type eyes and Miniature wings (genotype X^m Y).

Step by step solution

01

Identify the genotypes of the parent flies

The problem states that we have an attached-X female fly with genotype XXY, showing the X-linked recessive white-eye phenotype. This means the genotype of this female fly is (X^w X^w Y), with X^w representing the allele for white eyes. We also have a male fly expressing the X-linked recessive miniature wing phenotype, which means its genotype is (X^m Y), where X^m represents the allele for miniature wings.
02

Determine the possible gametes

Now, let's consider the possible gametes each parent fly can produce. The female fly (X^w X^w Y) can produce two types of gametes: X^w and Y. The male fly (X^m Y) can also produce two types of gametes: X^m and Y.
03

Use a Punnett square to predict offspring genotypes

To predict the genotypes of the offspring, we will use a Punnett square. In this case, we have a 2x2 Punnett square with female gametes on the top and male gametes on the side: X^w Y ____________ X^m | | X^w X^m | X^m Y | ____________ Y | | X^w Y | Y Y | ____________
04

Analyze the genotypes and determine the phenotypes of the offspring

We can now analyze the genotypes and phenotypes of the offspring. The four possible genotypes are: 1. X^w X^m: Female with one dominant eye-color allele and one recessive miniature wing allele. (Wild-type eyes, Miniature wings) 2. X^w Y: Male with a recessive eye color allele (White eyes, Wild-type wings) 3. X^m Y: Male with a recessive wing-size allele (Wild-type eyes, Miniature wings) 4. Y Y: This genotype is not viable in flies – no offspring. Overall, the offspring will have the following genotypes and phenotypes: Females: - 50% with Wild-type eyes and Miniature wings (genotype X^w X^m). Males: - 50% with White eyes and Wild-type wings (genotype X^w Y). - 50% with Wild-type eyes and Miniature wings (genotype X^m Y).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Study anywhere. Anytime. Across all devices.

Sign-up for free