Question

You decided to grow some pepper plants: one of those plants yielded peppers that were mild and green, while the other produced fruits that were spicy and red. You then wanted to know whether the genes responsible for these traits were linked, so you crossed your true-breeding plants and got an F1 generation that produced peppers that were mild tasting and green. You then took those F1 plants and backcrossed them to your original plant that produced spicy, red peppers. The offspring of that cross and the types of peppers they produce are listed below.

425 mild, green; 375 red, spicy; 125 mild, red; 75 green, spicy
1. What is the number of offspring that are "parental" types [ Select] ?
2. What is the number of offspring that are "recombinant" types [ Select] ?
3. What is the recombination frequency for these two traits [Select] ?

Answer 1

1. Number of parental types: Offspring plants inherit traits from the parent plant they were crossed with. In this situation, the parent plants are light green (425) and red (375) with a spicy flavor. So, the total number of offspring with the same traits as their parents is 425 + 375 = 800.

2. Number of recombinant types: Recombinant types are plants that get traits from both parent plants. In this situation, the new types of mild-red (125) and green-spicy (75) are created. So, the total number of offspring with different traits is 125 + 75 = 200.

3. Recombination frequency is the measure of how often new combinations of genetic traits appear in offspring. To figure this out, we can divide the number of mixed types by the total number of offspring and then times by 100.

The recombination frequency is calculated by dividing the number of offspring showing a new combination of traits by the total number of offspring, and then multiplying it by 100.

Recombination frequency = (200 / 1000) * 100

Recombination frequency = 20%

Hence, the recombination frequency for these two traits is 20%..