Question

in a dihybrid cross for round and yellow seeds (rryy x rryy), what is the probability of having green and wrinkled seeds? key: r = round r = wrinkled y = yellow y = green
○ 1:16
○ 3:16
○ 8:16
○ 9:16

Explanation:

Step1: Analyze seed shape (R/r)

For the shape (round/ wrinkled), the cross is \( Rr \times Rr \). The Punnett square gives genotypes \( RR, Rr, Rr, rr \). So probability of wrinkled (\( rr \)) is \( \frac{1}{4} \).

Step2: Analyze seed color (Y/y)

For color (yellow/ green), the cross is \( Yy \times Yy \). Punnett square gives \( YY, Yy, Yy, yy \). Probability of green (\( yy \)) is \( \frac{1}{4} \).

Step3: Combine probabilities

Since shape and color are independent, multiply probabilities: \( \frac{1}{4} \times \frac{1}{4} = \frac{1}{16} \), so ratio is \( 1:16 \).

Answer:

1:16