The estimate of degree of variation in a phenotypic trait in a population that is due to genetic variation between individuals in that population is called as

Correct option is B

✅ (b) Heritability [Genetic Contribution to Variation] • Heritability quantifies how much of phenotypic variation in a trait is due to genetic differences. • Expressed as a percentage or value from 0 to 1. • Important in breeding programs to estimate genetic gains. • High heritability means trait is strongly controlled by genes.
❌ (c) Expressivity • Describes the degree of expression of a gene in individuals with the same genotype. • Not a measure of genetic vs environmental variation.
❌ (a) Pleiotropy • When a single gene affects multiple traits. • Unrelated to population-level variation estimates.
❌ (d) Penetrance • Refers to the percentage of individuals showing the phenotype for a given genotype. • Not a population variability measure.