In drosophila , short wings , and black colour are reccessive traits.long wings and grey colour are dominant. show the cross results between a short winged , heterozygous grey fly and a heterzygous long winged grey fly
To determine the cross results between a short-winged, heterozygous grey fly (SsGg) and a heterozygous long-winged grey fly (SsGg) in Drosophila, you can use a Punnett square.
First, let's break down the genotypes of the parent flies:
- Short-winged, heterozygous grey fly (SsGg):
- Short wing trait (S):
- One allele is short (s)
- Grey color trait (G):
- One allele is grey (g)
- Heterozygous long-winged grey fly (SsGg):
- Long wing trait (S):
- One allele is long (S)
- Grey color trait (G):
- One allele is grey (g)
To create a Punnett square, you'll need to write out all the possible combinations of alleles that can be produced by the parental flies. In this case, since both flies are heterozygous for both traits, they can pass on either the dominant or recessive alleles for each trait.
Here's the Punnett square for this cross:
| Sg | Sg |
-------------------------
Sg | SSgg | Ssgg |
-------------------------
Sg | SSgg | Ssgg |
Now let's interpret the results:
- Genotypes:
- 25% of the offspring will have the genotype SSGG (long wings, grey color).
- 25% of the offspring will have the genotype SSgg (long wings, black color).
- 25% of the offspring will have the genotype SsGG (short wings, grey color).
- 25% of the offspring will have the genotype Ssgg (short wings, black color).
- Phenotypes:
- 50% of the offspring will have long wings.
- 50% of the offspring will have short wings.
- 75% of the offspring will have grey color.
- 25% of the offspring will have black color.
So, based on the Punnett square, the cross between a short-winged, heterozygous grey fly and a heterozygous long-winged grey fly in Drosophila will result in offspring with a combination of different wing lengths (short and long) and colors (grey and black).