Look at the Punnett square, which shows the predicted offspring of the F2 generation from a cross between a plant with yellow-round seeds (YYRR) and a plant with green-wrinkled seeds (yyrr). Select the correct statement about wrinkled yellow seeds in the F2 generation.

Question

Wrinkled and yellow traits are linked in peas.
The chance that an individual taken at random from the F2 generation produces wrinkled seeds is 25% and the chance that the same individual produces yellow seeds is 75%.
In a set of 16 individuals from the F2 generation, 3 will produce wrinkled yellow seeds.

Answer 1

To analyze the situation, let's break down the cross between a plant with yellow-round seeds (YYRR) and a plant with green-wrinkled seeds (yyrr) using a Punnett square.

1. P Generation:

   • Parent 1 (YYRR - homozygous yellow and round)
   • Parent 2 (yyrr - homozygous green and wrinkled)

2. F1 Generation: All offspring will receive one allele from each parent:

   • All will be YyRr (heterozygous for both traits, phenotypically yellow and round).

3. F2 Generation: The F1 generation (YyRr) is then crossed with itself (YyRr):

   • The phenotypic ratio for the F2 generation from this dihybrid cross can be derived from the combination of traits:
     • Yellow/round (YYRR, YYRr, YyRR, YyRr): 9/16
     • Yellow/wrinkled (YYrr, Yyrr): 3/16
     • Green/round (yyRR, yyRr): 3/16
     • Green/wrinkled (yyrr): 1/16

From this, we see that:

• The chance that an individual produces wrinkled seeds (which can only be yellow-wrinkled because wrinkled is recessive) is represented by the yellow-wrinkled ratio. The probability for yellow-wrinkled seeds = 3/16.
• The chance that an individual produces yellow seeds (which includes both round and wrinkled) = 12/16 (9 round + 3 wrinkled = 12 yellow).

Let's evaluate the statements:

1. Wrinkled and yellow traits are linked in peas: This statement is incorrect as yellow is dominant over green, and round is dominant over wrinkled; hence they assort independently according to Mendel's laws unless stated otherwise (linkage is not indicated here).

2. The chance that an individual taken at random from the F2 generation produces wrinkled seeds is 25% (3 out of 16) and the chance that the same individual produces yellow seeds is 75% (12 out of 16): This is also incorrect, as the yellow trait includes both wrinkled and round so the chance of producing yellow seeds should be 12/16.

3. In a set of 16 individuals from the F2 generation, 3 will produce wrinkled yellow seeds: This statement is accurate (3 will be yellow-wrinkled).

In conclusion, based on the analysis, the correct statement about wrinkled yellow seeds in the F2 generation is the third statement: "In a set of 16 individuals from the F2 generation, 3 will produce wrinkled yellow seeds."