Question

Складіть схему схрещування і запишіть розв'язання задачі у дрозофіли ген який визначає колір тіла розташований у Ікс хромосомі його домінантний алель б зумовлює сіре забарвлення тіла рецесивний алель жовте забарвлення тіла схрестили самку яка має жовтий колір тіла і самцем тіло якого має сіре забарвлення які генотипи і фенотипи матимуть нащадки від цього схрещування

Answer 1

Bb*BB
G bb BB
F1 Bb Bb

Answer 2

Scheme of the Cross and Solution to the Problem in Drosophila

In Drosophila, the gene that determines body color is located on the X chromosome. The dominant allele, "B," results in gray body color, while the recessive allele, "b," results in yellow body color. We are crossing a female with yellow body color (bb) and a male with gray body color (Bb). Let's determine the genotypes and phenotypes of the offspring from this cross.

To solve this problem, we can use a Punnett square, which is a visual representation of the possible combinations of alleles from the parents. In this case, we will use a modified Punnett square for an X-linked trait.

Punnett Square for the Cross:

| | Xb | Xb | |-------|--------|--------| | Bb | BbXb | BbXb | | bb | bbXb | bbXb |

The Punnett square shows the possible genotypes of the offspring resulting from the cross. Now, let's determine the phenotypes associated with each genotype.

Genotypes and Phenotypes of the Offspring:

1. BbXb: This genotype represents a female with gray body color. The dominant allele "B" determines the gray color, while the recessive allele "b" determines the yellow color. The phenotype is gray body color.

2. bbXb: This genotype represents a female with yellow body color. Both alleles are recessive, so the phenotype is yellow body color.

3. BbXb: This genotype represents a male with gray body color. The dominant allele "B" determines the gray color, while the recessive allele "b" determines the yellow color. The phenotype is gray body color.

4. bbXb: This genotype represents a male with yellow body color. Both alleles are recessive, so the phenotype is yellow body color.

Therefore, the offspring from this cross will have a 1:1 ratio of gray body color to yellow body color, with both males and females exhibiting both phenotypes.

Please let me know if there is anything else I can help you with!