If two parents each have one dominant allele and one recessive allele for curly hair (Cc), what is the probability they will create an offspring with two recessive alleles? Draw a Punnet square to explain your answer.
The probability that they will create an offspring with two recessive alleles is 25%.
Punnet Square:
C | c
---------
C | c
To determine the probability of two parents with one dominant allele and one recessive allele for curly hair (Cc) creating an offspring with two recessive alleles, we can use a Punnett square.
Let's represent the dominant allele "C" for curly hair and the recessive allele "c" for straight hair.
The Punnett square for the parents with genotype Cc would look like this:
| C | c |
-----------------------------------
C | CC | Cc |
-----------------------------------
c | Cc | cc |
-----------------------------------
Based on the Punnett square, there are four possible combinations of alleles for the offspring: CC, Cc, Cc, and cc.
Therefore, the probability of the parents creating an offspring with two recessive alleles (cc) is 1 out of 4 possibilities or 1/4.
So, the probability is 25% or 0.25.
To determine the probability of the parents creating an offspring with two recessive alleles for curly hair (cc), we can use a Punnett square. The Punnett square allows us to visualize the possible combinations of alleles that could be inherited from each parent.
Let's represent the dominant allele (C) as uppercase and the recessive allele (c) as lowercase. Since both parents have one dominant allele (C) and one recessive allele (c), their genotypes would be Cc.
To create a Punnett square, we will list each parent's possible gametes horizontally and vertically, and then combine them to determine the possible genotypes of the offspring.
Parent 1 (Female): Cc
Parent 2 (Male): Cc
C c
------------
C | CC | Cc |
------------
c | Cc | cc |
------------
Let's analyze the Punnett square:
- There are four possible combinations of alleles (genotypes) that the offspring might inherit: CC, Cc, Cc, and cc.
- Only one of the four combinations (cc) represents the offspring having two recessive alleles for curly hair.
Therefore, the probability of the parents creating an offspring with two recessive alleles for curly hair (cc) is 1 out of 4, which can also be expressed as 1/4 or 25%.