Height and Body Build Factors Explained

The assertion states that height and body build are primarily inherited characteristics, but good nutrition and exercise can also influence them. This statement is factually correct. While our genes set a potential range for our physical traits, environmental factors significantly shape the outcome. For instance, sufficient nutrients are crucial for growth, and physical activity contributes to muscle mass and overall physique, demonstrating that nurture plays a vital role alongside nature.

Heredity and Environment Interaction in Development

The reason explains that heredity and environment interact in their effects on development. This is a fundamental principle in biology and psychology. Development is a complex process resulting from the continuous interplay between an individual's genetic makeup (heredity) and their surroundings, experiences, and lifestyle choices (environment). Neither factor acts in isolation; they constantly influence each other.

Developmental Interaction Explanation

Reason (R) provides the underlying principle that explains why Assertion (A) is true. The assertion describes a specific scenario (influence on height and body build) where both inherited traits and environmental factors are at play. The reason generalizes this observation by stating the universal principle of heredity-environment interaction in development. The way nutrition and exercise affect height and body build, despite their genetic basis, is a direct consequence of this interaction. Thus, Reason (R) correctly elaborates on the mechanism behind the observation made in Assertion (A).

Conclusion on Assertion and Reason Validity

Considering the analysis:

• Assertion (A) is true: Height and body build are influenced by both genetics and environmental factors like nutrition and exercise.
• Reason (R) is true: Heredity and environment indeed interact throughout development.
• Reason (R) is the correct explanation of (A): The principle of interaction explains why environmental factors can modify genetically influenced traits like height and body build.

Therefore, the correct option identifies both statements as true and establishes the reason as a valid explanation for the assertion.