Class 12 Botany simulations · Principles of Inheritance and Variation

Dihybrid cross: independent assortment

Cross pea plants for seed shape and colour. Fill the 4 × 4 Punnett square and count the phenotypes.

Open the simulation

What to notice

The two pairs of factors segregate independently of each other when gametes form.

Key relation

RrYy × RrYy → 9 round yellow : 3 round green : 3 wrinkled yellow : 1 wrinkled green

Try this

Make a test cross (RrYy × rryy). What ratio appears?

What you can change

• Parent 1: choose RrYy (dihybrid), RRYY (round yellow), rryy (wrinkled green), Rryy, rrYy
• Parent 2: choose RrYy (dihybrid), RRYY (round yellow), rryy (wrinkled green), Rryy, rrYy

More in Principles of Inheritance and Variation

• Incomplete dominance and co-dominance
• Mendel’s monohybrid cross
• Sex determination and X-linked traits

See all Class 12 Botany simulations or every Physica simulation.