10. Which one of the following statements is true regarding heritability of a quantitative character?
(1) The estimate obtained from a given population and in one set of environment can be extrapolated to other population and sets of environment
(2) The estimate is a population as well as an individual parameter.
(3) Heritability measures the proportion of the phenotypic variation that is the result of genetic factors
(4) Heritability indicates the degree to which a trait is genetic.

The true statement regarding the heritability of a quantitative character is:

(3) Heritability measures the proportion of the phenotypic variation that is the result of genetic factors.

Explanation of options:

1. The estimate obtained from one population and environment cannot be generalized or extrapolated to other populations or environments because heritability is specific to both population and environment conditions.

2. Heritability is a population-level parameter that describes genetic contribution to variation within a group, not an individual parameter.

3. Correct: Heritability quantifies the proportion of total phenotypic variation in a trait attributable to genetic differences among individuals in that population.

4. Heritability does not indicate the degree to which a trait is genetic in an absolute sense; rather, it indicates how much variation in a trait within a population is due to genetic variation, and this can vary with environmental context.

Introduction: Heritability is a fundamental concept in genetics, especially in the study of quantitative characters that show continuous variation in populations. It helps researchers and breeders understand how much of the variation in traits like height, weight, or yield can be attributed to genetic factors as opposed to environment. Clarifying misconceptions around heritability can empower better interpretation of genetic studies and breeding approaches.

Detailed Explanation:

• Heritability is a population parameter that measures the proportion of phenotypic variance in a trait due to genetic variance in that particular population and environment. It cannot be applied to individuals or generalized across different populations or environments.

• The parameter is estimated as the ratio of genetic variance to total phenotypic variance (genetic + environmental variance). This estimation reveals how much genetic differences contribute to observed differences in traits among individuals.

• Importantly, heritability does not measure how genetic a trait is in an absolute sense. Even a trait with high heritability could be strongly influenced by the environment if measured in different contexts.

• Understanding heritability is critical in fields like plant and animal breeding, genetics, and evolutionary biology, where it guides selection and prediction of trait response.

This makes option (3) the correct choice when evaluating the true statement about heritability of quantitative characters.