What is the probability of obtaining a heterozygous offspring from a cross betwe
Practice Questions
Q1
What is the probability of obtaining a heterozygous offspring from a cross between two heterozygous parents (Aa x Aa)?
0
1/4
1/2
3/4
Questions & Step-by-Step Solutions
What is the probability of obtaining a heterozygous offspring from a cross between two heterozygous parents (Aa x Aa)?
Correct Answer: 1/2
Step 1: Understand the terms. 'Heterozygous' means having two different alleles for a gene, like 'Aa'.
Step 2: Identify the parents in the cross. Both parents are heterozygous (Aa).
Step 3: Set up a Punnett square. Draw a 2x2 grid to represent the possible combinations of alleles from the parents.
Step 4: Fill in the Punnett square. The top of the square will have the alleles from one parent (A and a), and the side will have the alleles from the other parent (A and a).
Step 5: Combine the alleles in the squares. The combinations will be: AA, Aa, aA, aa.
Step 6: Count the outcomes. There are 4 total combinations: 1 AA, 2 Aa (heterozygous), and 1 aa.
Step 7: Calculate the probability of heterozygous offspring. There are 2 heterozygous outcomes (Aa) out of 4 total outcomes.
Step 8: Simplify the probability. 2 out of 4 simplifies to 1 out of 2, or 1/2.
