What is the probability of obtaining a homozygous recessive offspring from a cro
Practice Questions
Q1
What is the probability of obtaining a homozygous recessive offspring from a cross between two heterozygous parents (Aa x Aa)?
0.25
0.50
0.75
1.00
Questions & Step-by-Step Solutions
What is the probability of obtaining a homozygous recessive offspring from a cross between two heterozygous parents (Aa x Aa)?
Correct Answer: 0.25 or 25%
Step 1: Understand the genotypes of the parents. Both parents are heterozygous, meaning they have one dominant allele (A) and one recessive allele (a). So, their genotypes are Aa and Aa.
Step 2: Set up a Punnett square to visualize the possible combinations of alleles from the parents. The rows and columns will represent the alleles from each parent.
Step 3: Fill in the Punnett square. The combinations will be: AA, Aa, Aa, and aa.
Step 4: Count the total number of offspring combinations. There are 4 combinations in total.
Step 5: Identify the homozygous recessive combination (aa). There is 1 combination of aa.
Step 6: Calculate the probability of obtaining aa. This is done by dividing the number of aa combinations (1) by the total number of combinations (4). So, 1/4 = 0.25.
Step 7: Convert the probability to a percentage. 0.25 is equivalent to 25%.
