long wings are dominant to short wings in fruit flies. make a punnett square to show the predicted outcome of a cross between two parents that have both alleles for wing length. what is the ratio of flies produced?
To create a Punnett square to represent the predicted outcome of a cross between fruit flies with alleles for long wings (LL) and short wings (ss), we need to identify the genotypes of both parents. Since the parents have both alleles for wing length, they are heterozygous, meaning they have one copy of the long wings allele (L) and one copy of the short wings allele (s). Thus, the genotypes of the parents would be Ls.
To construct the Punnett square, list the possible allele combinations that can be formed from the parents' alleles on the top and left side of the square. In this case, it would be L and s. Then, fill in the squares by combining the alleles from the corresponding row and column.
| L | s |
-------------------------------
L | LL | Ls |
-------------------------------
s | Ls | ss |
-------------------------------
The Punnett square above shows four possible combinations of alleles in the offspring: LL, Ls, Ls, and ss. Now we can determine the ratio of flies produced by counting the number of each genotype:
- LL: Appears once in the Punnett square.
- Ls: Appears twice in the Punnett square.
- ss: Appears once in the Punnett square.
Therefore, the ratio of flies produced would be 1:2:1 (LL : Ls : ss).
To create a Punnett square for a cross between two fruit flies with both alleles for wing length, we can represent the alleles for long wings as "L" and the alleles for short wings as "S."
The possible genotypes of the parents are LL (long wings) and SS (short wings).
Let's create a Punnett square:
| L | L
----|-----------
S | LS | LS
In this Punnett square, we can see that all the offspring will have the genotype LS, which translates to long wings.
Therefore, the predicted outcome is that all the fruit flies produced will have long wings. The ratio of flies produced with long wings to short wings is 4:0 or 100% long wings.