🎓 Biology • Genetics
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Genetics Probability Calculator
Computes joint and conditional probabilities for independent genetic loci using Mendelian probability rules.
⭐ Classic Biological Presets & Clinical Scenarios:
Mendelian Product Rule Calculator
$P(A \cap B) = P(A) \times P(B)$: Joint probability of unlinked, independent genetic events
e.g. 0.75 (3/4 dominant)
e.g. 0.25 (1/4 recessive)
Optional third trait
Joint Independent Probability
0.1875 (18.75%)
P(A ∩ B) = P(A) × P(B) = 0.75 × 0.25 = 0.1875 (18.75%)
Probability in Genetics
Mendelian genetics relies on mathematical probability: the Rule of Multiplication determines joint independent events, while the Rule of Addition determines mutually exclusive outcomes.
Formula & Step-by-Step Calculation
P(A and B) = P(A) × P(B), P(A or B) = P(A) + P(B)
Product and sum rules of probability applied to independent allele segregation.
Worked Step-by-Step Examples
Example 1
Probability of an offspring being dominant for Trait 1 (3/4) AND recessive for Trait 2 (1/4)
Solution: 3/16 (0.1875 or 18.75%)
• (3/4) × (1/4) = 3/16 ≈ 0.1875
Common Real-World & Academic Use Cases
- ✓ Clinical genetic pedigree carrier risk assessment
- ✓ Multi-trait horticultural breeding forecasts
- ✓ Statistical genetics hypothesis testing
How to Use the Genetics Probability Calculator
1
Input Trait Probabilities
Enter probabilities for each independent gene locus (0 to 1).
2
Calculate Joint Odds
Review the combined percentage and decimal odds.
Frequently Asked Questions
Q: When can the multiplication rule be applied?
Only when the gene loci sort independently (unlinked genes located on different chromosomes or far apart).