1. What Is A Dihybrid Cross?

A dihybrid cross is a breeding experiment between two organisms that are identically hybrid for two traits. This cross examines the inheritance of two different traits simultaneously, following Mendel's principle of independent assortment.

2. How Does The Calculator Work?

The calculator predicts the expected phenotypic ratio of offspring from a dihybrid cross:

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: This ratio assumes independent assortment of genes and complete dominance for both traits.

3. Understanding The 9:3:3:1 Ratio

Details: The 9:3:3:1 ratio is the classic phenotypic ratio expected from a dihybrid cross where both parents are heterozygous for both traits and the genes assort independently.

4. Using The Calculator

Tips: Enter the genotype information for both traits from each parent. Use standard genetic notation (e.g., AaBb for heterozygous genotypes).

5. Frequently Asked Questions (FAQ)

Q1: What assumptions does this calculator make?
A: It assumes independent assortment, complete dominance, no gene linkage, and no epistasis between the two traits.

Q2: When does the 9:3:3:1 ratio not apply?
A: When genes are linked on the same chromosome, when there's epistasis, or when dominance is incomplete.

Q3: How is this different from a monohybrid cross?
A: A monohybrid cross examines one trait (3:1 ratio), while a dihybrid cross examines two traits simultaneously (9:3:3:1 ratio).

Q4: Can I use this for more than two traits?
A: No, this calculator is specifically designed for dihybrid crosses (two traits). For more traits, different calculations are needed.

Q5: What if my actual results differ from the expected ratio?
A: Deviations may indicate genetic linkage, sampling error, or other factors affecting Mendelian inheritance patterns.