The following pairs of traits are examples of continuous and discontinuous variations respectively except

Step 1: Analyze the question We need the pair that is NOT "continuous, then discontinuous" in that order. Every other option should have a continuous trait first and a discontinuous trait second.

Step 2: Concept

• Continuous variation: a full range of intermediate forms, with no clear-cut groups. It is controlled by many genes (polygenic) and is influenced by the environment. Examples: height, body weight, skin colour, and hand span.
• Discontinuous variation: distinct categories with no intermediates. It is controlled by one or a few genes and is little affected by the environment. Examples: blood group, tongue rolling, fingerprint type, sex, and the ability to taste PTC.

Step 3: Check each option

• A. Eye colour and body weight: Eye colour is usually treated as discontinuous (distinct categories such as brown, blue, black), while body weight is continuous. This is the reverse of the required order (continuous, then discontinuous), so it does not fit the pattern.
• B. Height and blood group: continuous, then discontinuous. Fits.
• C. Skin colour and fingerprints: continuous, then discontinuous. Fits.
• D. Body weight and tongue rolling: continuous, then discontinuous. Fits.

Step 4: Answer Options B, C and D all follow the pattern, so the exception is A.

Tip: In "except" questions, find the one option that breaks the pattern. Remember that measurable traits (height, weight, skin colour) are continuous, while "either/or" traits (blood group, tongue rolling, sex) are discontinuous. Also check the order of the pair.