1. What is a Dihybrid Cross?

A dihybrid cross examines the inheritance of two different traits simultaneously. According to Mendel's principles, these traits assort independently, resulting in a characteristic 9:3:3:1 phenotypic ratio in the F2 generation.

2. How Does the Calculator Work?

The calculator simulates a dihybrid cross between two heterozygous parents (AaBb × AaBb):

Where:

• 9 — Dominant for both traits
• 3 — Dominant for first trait, recessive for second
• 3 — Recessive for first trait, dominant for second
• 1 — Recessive for both traits

Explanation: The calculator determines all possible gamete combinations and predicts offspring genotypes and phenotypes.

3. Understanding the 9:3:3:1 Ratio

Details: This ratio emerges from independent assortment of two genes on different chromosomes during meiosis, demonstrating Mendel's Law of Independent Assortment.

4. Using the Calculator

Tips: Enter 4-letter genotypes for each parent (e.g., AaBb). Capital letters represent dominant alleles, lowercase for recessive. The calculator will show the expected phenotypic ratio.

5. Frequently Asked Questions (FAQ)

Q1: What if my ratio isn't exactly 9:3:3:1?
A: Real-world results may vary due to sample size, genetic linkage, or other factors. The ratio represents expected probabilities.

Q2: Does this work for linked genes?
A: No, linked genes on the same chromosome don't assort independently and won't produce a 9:3:3:1 ratio.

Q3: How many gametes are possible in a dihybrid cross?
A: Each parent produces 4 possible gamete combinations (for two heterozygous genes).

Q4: What's the genotypic ratio?
A: The genotypic ratio is more complex (1:2:1:2:4:2:1:2:1 for AABB:AABb:AAbb:AaBB:AaBb:Aabb:aaBB:aaBb:aabb).

Q5: Can I use this for trihybrid crosses?
A: No, this calculator is specifically for dihybrid crosses. Trihybrid crosses have more complex ratios.