Question

Answer the following: (ii) What is a dominant trait?

Answer 1

Definition of dominant trait:

• The dominant trait is coded by a dominant allele.
• The dominant allele is expressed irrespective of the presence of another allele. It expresses itself under homozygous as well as heterozygous conditions.
• A dominant allele suppresses the effect of recessive allele.

Examples of dominant traits:

• In Mendel's experiment, the character of tallness of plant is governed by T and t alleles of a gene, where T represents a dominant trait and it dominates over t (dwarf) allele.
• The contrasting traits follow the laws of inheritance proposed by Mendel.
• Therefore, in an individual (Tt) where T and t are present together, only T expresses and the expression of the t remains suppressed (recessive).
• Similarly, Rr plant will have round seeds whereas rr will have wrinkled seeds.

Characteristic	1st contrasting trait (dominant)	2nd contrasting trait (recessive)
Height	Tall (T)	Dwarf (t)
Seed shape	Round (R)	Wrinkled (r)