Simran Vinaik
Last Activity: 7 Years ago
To solve the genetic problem you've presented, we need to analyze the cross between two individuals with specific genotypes: AaBBCcDd and AaBbccDd. The goal is to determine the percentage probability of obtaining the genotype AABBCcDd in the offspring.
Understanding the Parent Genotypes
Let’s break down the parent genotypes into their alleles:
- Parent 1 (AaBBCcDd):
- A: Two alleles (A and a)
- B: Two alleles (B and B)
- C: Two alleles (C and c)
- D: Two alleles (D and d)
- Parent 2 (AaBbccDd):
- A: Two alleles (A and a)
- B: Two alleles (B and b)
- C: One allele (c)
- D: Two alleles (D and d)
Setting Up the Punnett Square
To find the offspring genotype probabilities, we can use a Punnett square approach for each gene individually, then combine the results across all genes.
1. Allele Combinations for Each Gene
We will list the possible gametes from each parent:
- Parent 1 can produce: ABcD, ABcd, AbcD, Abcd, aBcD, aBcd, abcD, abcd
- Parent 2 can produce: ABcD, ABcd, AbcD, Abcd, aBcD, aBcd, abcD, abcd
2. Finding Combinations for A, B, C, and D
Now, let’s evaluate each gene:
- Gene A:
- From Parent 1: A or a
- From Parent 2: A or a
- Combinations: AA, Aa, Aa, aa
- Gene B:
- From Parent 1: B or B
- From Parent 2: B or b
- Combinations: BB, Bb, BB, Bb
- Gene C:
- From Parent 1: C or c
- From Parent 2: c only
- Combinations: Cc, cc
- Gene D:
- From Parent 1: D or d
- From Parent 2: D or d
- Combinations: DD, Dd, dD, dd
Calculating the Probability
For the specific genotype AABBCcDd, we need to determine how many offspring would match this combination:
- A: There is a probability of 1/4 for AAB (from AA) and 1/2 for B (from BB or Bb).
- B: The probability for BB is 3/4.
- C: The probability for Cc is 1/2.
- D: The probability for Dd is also 1/2.
Final Probability Calculation
Now we can combine these probabilities:
Probability of AABBCcDd = (1/4) * (3/4) * (1/2) * (1/2) = 3/32
Converting to Percentage
To express this as a percentage, we multiply by 100:
Percentage = (3/32) * 100 ≈ 9.375%
Thus, the likelihood of obtaining an offspring with the genotype AABBCcDd from this cross is approximately 9.375%. This approach illustrates how to analyze genetic crosses methodically, allowing you to predict potential outcomes in offspring.