Question

A dihybrid cross is performed between plants that differ in two Mendelian traits: Stem length (T or t) and flower coloration (R or r). Tall plants are dominant to small plants and red flowers are dominant to white flowers. The cross is between two TtRr individuals.What is the expected ratio of offspring that have tall stems and white flowers? A. 3/16 B. 1/16 C. 3/4 D. 9/16 E. 1/4

Answer 1

Answer:

A. 3/16

Explanation:

The four possible outcomes for Stem length are:

Tt, tT, TT and tt.

The dominant trait (tall stems) will manifest itself in 3 out of 4 outcomes, so its ratio is 3/4.

The four possible outcomes for flower coloration are:

Rr, rR, RR and rr.

The non-dominant trait (white flowers) will manifest itself in 1 out of 4 outcomes, so its ratio is 1/4.

Multiplying both ratios gives us the ratio of offspring that have tall stems and white flowers:

$\frac{3}{4}*\frac{1}{4}=\frac{3}{16}$

Therefore, the answer is A. 3/16