The F₂ **phenotypic** ratio of a Mendelian dihybrid cross is:
- 3 : 1
- 1 : 2 : 1
- 9 : 3 : 3 : 1
- 1 : 1 : 1 : 1
Show answer and solution
Correct answer: C. 9 : 3 : 3 : 1
Dihybrid TtRr × TtRr → 16 combinations.
Phenotype ratio = 9 (T_R_) : 3 (T_rr) : 3 (ttR_) : 1 (ttrr) — the classic 9:3:3:1 dihybrid ratio, illustrating the law of independent assortment.