Question

In a particular bird species, the tips of the feathers are tinged with blue, white, or silver. The BB genotype calls for blue-tipped feathers. The WW genotype calls for white-tipped feathers. The BW genotype calls for an intermediate with silver-tipped feathers. A mating occurs between two silver-tipped birds.

What is the probability of blue tipped offspring? %

What is the probability of silver tipped offspring? %

What is the probability of white tipped offspring? %

Answer 1

In this particular bird species, we have three genotypes that correspond to different feather tip colors:

- **BB**: blue-tipped feathers
- **WW**: white-tipped feathers
- **BW**: silver-tipped feathers

When two silver-tipped birds mate, both birds have the BW genotype. We can set up a Punnett square to determine the probabilities of the offspring's genotypes.

The possible gametes from each BW parent are B and W. Thus, the Punnett square will look like this:

```
B W
+-------+
B | BB | BW |
+-------+
W | BW | WW |
+-------+
```

From the Punnett square, we can see the potential genotypes for the offspring:

- BB: 1 (blue-tipped feathers)
- BW: 2 (silver-tipped feathers)
- WW: 1 (white-tipped feathers)

Now we can calculate the probabilities:

1. **Probability of blue-tipped offspring (BB)**:
- There is 1 BB out of 4 total genotypes.
- Probability = \( \frac{1}{4} = 25\% \)

2. **Probability of silver-tipped offspring (BW)**:
- There are 2 BW out of 4 total genotypes.
- Probability = \( \frac{2}{4} = \frac{1}{2} = 50\% \)

3. **Probability of white-tipped offspring (WW)**:
- There is 1 WW out of 4 total genotypes.
- Probability = \( \frac{1}{4} = 25\% \)

In summary, the probabilities are:
- Blue-tipped offspring: **25%**
- Silver-tipped offspring: **50%**
- White-tipped offspring: **25%**