For hair color, Brown (B) is a dominant trait and Blond (b) is a recessive trait. If one parent has pure blond hair and one parent has hybrid brown hair, complete the Punnett square and questions that follow.
a) What is the probability that their first child will have pure brown hair?
b) What is the probability that their first child will have blond hair?
c) What is the probability that their first child will have brown hair?
a) Well, if one parent has pure blond hair (bb) and the other has hybrid brown hair (Bb), there's a 0% chance of their first child having pure brown hair. Sorry, no chocolate locks for the little one.
b) The probability that their first child will have blond hair is 50%. It's like flipping a coin, but instead of heads or tails, it's blond or not.
c) The probability that their first child will have brown hair is also 50%. But don't worry, it's not just any brown hair – it's hybrid brown, the perfect mix of blond and brown. They'll be rocking that unique look!
To complete the Punnett square for this scenario, we will use the following notation:
- The pure blond hair parent will be represented by the genotype bb.
- The hybrid brown hair parent will be represented by the genotype Bb.
Now let's complete the Punnett square:
| b | b |
----|------|------|---
B | Bb | Bb |
----|------|------|---
b | bb | bb |
a) Looking at the Punnett square, we see that there are 2 out of 4 possible outcomes where the child will have pure brown hair (Bb). So, the probability that their first child will have pure brown hair is 2/4 or 50%.
b) Again, looking at the Punnett square, we see that there are 2 out of 4 possible outcomes where the child will have blond hair (bb). So, the probability that their first child will have blond hair is 2/4 or 50%.
c) The probability that their first child will have brown hair, whether pure brown or hybrid, can be calculated by adding the probabilities of having pure brown hair (Bb) and the probability of having hybrid brown hair (Bb). From the Punnett square, we see that there are 2 out of 4 possible outcomes for each case. So, the probability that their first child will have brown hair is 2/4 + 2/4 = 4/4 or 100%.
To complete the Punnett square for the given scenario, we need to know the genotype of each parent. Let's represent the pure blond hair genotype as bb and the hybrid brown hair genotype as Bb. Using this information, we can now create the Punnett square.
Punnett square:
| b | b
-----------------------------
B | Bb | Bb
-----------------------------
b | bb | bb
Now let's answer the questions:
a) To find the probability of the first child having pure brown hair (BB), we look for the intersection of the genotype BB in the Punnett square. In this case, there are no BB genotypes present since neither parent has the BB genotype. Therefore, the probability is 0% (0 out of 4 possible combinations).
b) To find the probability of the first child having blond hair (bb), we look for the intersection of the genotype bb in the Punnett square. In this case, there are two bb genotypes present in the Punnett square. So, the probability is 50% (2 out of 4 possible combinations).
c) To find the probability of the first child having brown hair (Bb), we look for the intersection of the genotype Bb in the Punnett square. In this case, there are two Bb genotypes present in the Punnett square. So, the probability is 50% (2 out of 4 possible combinations).