To determine the chance that the offspring of two heterozygous rabbits (WwEe) will be black with short ears, we can set up two monohybrid crosses: one for fur color and one for ear length.
Step 1: Analyze the traits separately.
-
Fur color:
- The possible alleles are W (white, dominant) and w (black, recessive).
- The parental genotypes are Ww (both parents are heterozygous).
The possible gametes produced by each parent are W and w. The Punnett square for this cross would look like this:
| | W | w | |----|----|----| | W | WW | Ww | | w | Ww | ww |
The offspring genotypes are:
- WW (white)
- Ww (white)
- Ww (white)
- ww (black)
The probability of having black fur (ww) is 1 out of 4, or \( \frac{1}{4} \).
-
Ear length:
- The possible alleles are E (long ears, dominant) and e (short ears, recessive).
- The parental genotypes are Ee.
The possible gametes produced by each parent are E and e. The Punnett square for this cross would look like this:
| | E | e | |----|----|----| | E | EE | Ee | | e | Ee | ee |
The offspring genotypes are:
- EE (long ears)
- Ee (long ears)
- Ee (long ears)
- ee (short ears)
The probability of having short ears (ee) is 1 out of 4, or \( \frac{1}{4} \).
Step 2: Calculate the combined probability. To find the probability that an offspring is both black (ww) and has short ears (ee), we multiply the probabilities of each independent event:
\[ P(\text{black fur}) \times P(\text{short ears}) = \frac{1}{4} \times \frac{1}{4} = \frac{1}{16} \]
Thus, the chance that the offspring will be black with short ears is \(\frac{1}{16}\).
The answer is: a. 1/16.