Answer :
To solve this problem, let's analyze the information provided in the Punnett square:
1. Identify the genotypes and phenotypes:
- Homozygous Dominant (XX): This appears 1 time in the Punnett square.
- Heterozygous (Xx or xX): This appears 2 times in the Punnett square.
- Homozygous Recessive (xx): This appears 1 time in the Punnett square.
2. Determine the phenotypes based on the genotypes:
- Offspring with at least one dominant allele (either homozygous dominant or heterozygous) will exhibit the dominant phenotype.
- Offspring with both recessive alleles (homozygous recessive) will exhibit the recessive phenotype.
3. Count the total number of offspring and the distribution of phenotypes:
- Total number of offspring: There are 4 combinations in the Punnett square.
- Dominant phenotype: Includes both homozygous dominant and heterozygous offspring. Thus, there are 1 (homozygous dominant) + 2 (heterozygous) = 3 offspring with the dominant phenotype.
- Recessive phenotype: Consists of only homozygous recessive offspring. Hence, there is 1 offspring with the recessive phenotype.
4. Calculate the fractions of each phenotype:
- Fraction with dominant phenotype: [tex]\( \frac{\text{Number of offspring with dominant phenotype}}{\text{Total number of offspring}} = \frac{3}{4} = 0.75 \)[/tex]
- Fraction with recessive phenotype: [tex]\( \frac{\text{Number of offspring with recessive phenotype}}{\text{Total number of offspring}} = \frac{1}{4} = 0.25 \)[/tex]
Therefore, the prediction is that:
- 0.75 of the offspring would have the dominant phenotype
- 0.25 of the offspring would have the recessive phenotype.
1. Identify the genotypes and phenotypes:
- Homozygous Dominant (XX): This appears 1 time in the Punnett square.
- Heterozygous (Xx or xX): This appears 2 times in the Punnett square.
- Homozygous Recessive (xx): This appears 1 time in the Punnett square.
2. Determine the phenotypes based on the genotypes:
- Offspring with at least one dominant allele (either homozygous dominant or heterozygous) will exhibit the dominant phenotype.
- Offspring with both recessive alleles (homozygous recessive) will exhibit the recessive phenotype.
3. Count the total number of offspring and the distribution of phenotypes:
- Total number of offspring: There are 4 combinations in the Punnett square.
- Dominant phenotype: Includes both homozygous dominant and heterozygous offspring. Thus, there are 1 (homozygous dominant) + 2 (heterozygous) = 3 offspring with the dominant phenotype.
- Recessive phenotype: Consists of only homozygous recessive offspring. Hence, there is 1 offspring with the recessive phenotype.
4. Calculate the fractions of each phenotype:
- Fraction with dominant phenotype: [tex]\( \frac{\text{Number of offspring with dominant phenotype}}{\text{Total number of offspring}} = \frac{3}{4} = 0.75 \)[/tex]
- Fraction with recessive phenotype: [tex]\( \frac{\text{Number of offspring with recessive phenotype}}{\text{Total number of offspring}} = \frac{1}{4} = 0.25 \)[/tex]
Therefore, the prediction is that:
- 0.75 of the offspring would have the dominant phenotype
- 0.25 of the offspring would have the recessive phenotype.
Answer:
Explanation:If you cross a homozygous dominant individual (AA) with a homozygous recessive individual (aa), all offspring in the Punnett square would have the genotype Aa, and the phenotype would be dominant.
Remember, Punnett squares are a helpful tool in understanding the possible outcomes of genetic crosses and predicting genotypes and phenotypes of offspring.
