Question

19 multiple choice 1.5 points in a dihybrid cross of ttpp x ttpp, tall (t) vs. short (t) and purple (p) vs. white (p), what proportion would be tall/white? 9/16 3/16 1/16 1/4

Explanation:

Step1: Analyze height trait

For the height trait with cross Tt x Tt, using Punnett - square analysis, the ratio of tall (T_) to short (tt) is 3:1. The probability of being tall (T_) is $\frac{3}{4}$ since TT : Tt : tt = 1:2:1 and tall is represented by TT and Tt.

Step2: Analyze color trait

For the color trait with cross Pp x Pp, using Punnett - square analysis, the ratio of purple (P_) to white (pp) is 3:1. The probability of being white (pp) is $\frac{1}{4}$ since PP : Pp : pp = 1:2:1.

Step3: Use product rule

Since the two traits assort independently according to Mendel's law of independent assortment, the probability of being tall and white is the product of the probability of being tall and the probability of being white. So, $P(\text{tall and white})=\frac{3}{4}\times\frac{1}{4}=\frac{3}{16}$.

Answer:

B. 3/16