1. What is a Dihybrid Cross?

A dihybrid cross examines the inheritance of two different traits simultaneously. It demonstrates Mendel's principle of independent assortment, showing how alleles for different genes separate independently during gamete formation.

2. How Does the Calculator Work?

The calculator uses Punnett square methodology to predict offspring genotypes and phenotypes:

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 9:3:3:1 ratio emerges from the independent assortment of two heterozygous traits (AaBb × AaBb).

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

Details: This classic ratio appears when crossing two heterozygous parents for two traits that assort independently. It's the foundation of Mendelian genetics.

4. Using the Calculator

Tips: Enter genotypes for both parents using standard notation (e.g., AaBb). The calculator will show phenotypic and genotypic ratios of their potential offspring.

5. Frequently Asked Questions (FAQ)

Q1: Why is the ratio 9:3:3:1?
A: It results from the probability combinations when two heterozygous traits assort independently (3/4 × 3/4 = 9/16, etc.).

Q2: Does this always apply?
A: Only for independently assorting traits. Linked genes or epistasis can alter ratios.

Q3: How many squares in a dihybrid Punnett square?
A: 16 squares, representing all possible gamete combinations from both parents.

Q4: What's the difference between phenotypic and genotypic ratios?
A: Phenotypic ratio describes observable traits, genotypic ratio describes genetic makeup.

Q5: Can this predict actual offspring numbers?
A: It predicts probabilities - actual results may vary due to random chance in small samples.