A certain species of grasshopper can have red stripes, yellow stripes, or red and yellow stripes. An RR grasshopper has red stripes, a YY grasshopper has yellow stripes, and an RY grasshopper has red and yellow stripes.

Question

A grasshopper with red and yellow stripes mates with a grasshopper with yellow stripes.

What ratio would be expected in the phenotypes of their offspring?

Responses

3 with red and yellow stripes : 1 with yellow stripes
3 with red and yellow stripes : 1 with yellow stripes

2 with red stripes : 2 with yellow stripes

1 with red stripes : 2 with red and yellow stripes : 1 with yellow stripes

2 with red and yellow stripes : 2 with yellow stripes

GPT-4o mini · Answer

To determine the expected phenotypic ratio of the offspring when a grasshopper with red and yellow stripes (RY) mates with a grasshopper with yellow stripes (YY), we can analyze the potential genotypes of the offspring.

Here are the genotypes involved:

RY (red and yellow stripes)
YY (yellow stripes)

Next, we can set up a Punnett square to find the combinations of these alleles. The alleles from one parent (RY) will be on the top, and the alleles from the other parent (YY) will be on the side:

        Y      Y
      ----------------
    R |   RY   |  RY  |
      ----------------
    Y |   YY    |  YY  |
      ----------------

From this Punnett square, we see the possible genotypes of the offspring:

RY (red and yellow stripes)
RY (red and yellow stripes)
YY (yellow stripes)
YY (yellow stripes)

The phenotypes from these genotypes would result in:

2 RY (red and yellow stripes)
2 YY (yellow stripes)

Thus, the ratio of the phenotypes would be:

2 with red and yellow stripes : 2 with yellow stripes

This can be simplified to 1 : 1.

Therefore, the expected phenotypic ratio is:

2 with red and yellow stripes : 2 with yellow stripes