Question

The genotypic ratio obtained in the ${\text{F}}_2$ generation of Mendel’s monohybrid cross was ___.

• A. 3:1
• B. 3:1:2
• C. 2:3
• D. 1:2:1

Answer 1

The correct option is D 1:2:1

• In monohybrid cross, four offsprings were obtained in the ${\text{F}}_2$ generation.
• Out of the four types, one was homozygous dominant (TT), two were heterozygous dominant (Tt) and one was homozygous recessive (tt). Thus the ${\text{F}}_2$ genotypic ratio was 1:2:1.
• The phenotypic ratio was 3:1. $3/4^{th}$ of offsprings showed dominant phenotype, while $1/3^{rd}$ showed recessive phenotype.