Which of the following statements is not true about continuous variation? It

Step 1: Analyze the question We need the statement that is NOT true about continuous variation.

Step 2: The concept Continuous variation is variation in which individuals show a complete range of values between two extremes, with no distinct categories. Examples are height, weight, skin colour and yield in crops.

Its main features:

• It is controlled by many genes (polygenes), each with a small additive effect.
• It is strongly influenced by the environment. Height, for example, depends on nutrition as well as genes.
• When plotted, it gives a bell-shaped normal distribution curve.

Discontinuous variation is different. It is controlled by one or two pairs of genes, gives distinct categories (e.g. blood groups, tongue rolling, sickle-cell trait), and is little affected by the environment.

Step 3: Check each option

• A. Controlled by several genes: True for continuous variation.
• B. Influenced by environmental factors: True.
• C. Follows a normal distribution curve: True.
• D. Controlled by one or two pair(s) of genes: False. This describes discontinuous variation.

Step 4: Answer The statement that is not true is D.

Exam tip: Remember "Continuous = Many genes, Curve (bell-shaped), Climate (environment)". Anything with "one or two genes" or "distinct categories" points to discontinuous variation.