Question

In tomatoes, red fruit (R) is dominant over yellow fruit (r) and tallness (T) is dominant over dwarfness (t). A plant that is RrTT is crossed with a plant that is rrTt. What are the chances of an offspring being heterozygous for both traits?

Options

• None

• 1/2

• 1/4

• 9/16

Answer 1

1/4

Explanation:

The chances of an offspring being heterozygous for both traits (RrTt) from a cross between RrTT and rrTt is 1/4. This can be determined by analyzing the results of the separate crosses for each trait: Rr × rr yields a 1/2 chance of Rr, and TT × Tt yields a 1/2 chance of Tt, making the combined probability `1/2xx1/2`

= 1/4