In horses, black (B) is the dominant color; brown (b) is the recessive color. Consider the cross seen here, between two black horses (Bb). What is the probability that these two horses will have a foal that is brown?

Question

In horses, black (B) is the dominant color; brown (b) is the recessive color. Consider the cross seen here, between two black horses (Bb). What is the probability that these two horses will have a foal that is brown?
Responses
A	0%
B	25%
C	40%
D	50%

GPT-4o mini · Answer

To determine the probability of two black horses (Bb) having a brown foal, we need to examine the possible genetic combinations of their offspring.

When two Bb (heterozygous black) horses are crossed, we can represent their alleles as follows:

Parent 1: Bb
Parent 2: Bb

We can use a Punnett square to visualize the genetic combinations:

       B      b
     --------------
B |   BB   |   Bb   |
    |-------|-------|
b |   Bb   |   bb   |

From the Punnett square, we see the following genetic combinations:

BB: 1 (Black)
Bb: 2 (Black)
bb: 1 (Brown)

Now, we can calculate the probabilities:

Probability of BB = 1/4
Probability of Bb = 2/4 = 1/2
Probability of bb = 1/4

Since "bb" represents the brown color, the probability of having a brown foal is 1 out of 4, or 25%.

Thus, the probability that these two horses will have a foal that is brown is B 25%.