Question
NEET 2022 (paraphrased): Regarding pedigree analysis, which of the following statements is correct? (a) autosomal recessive refers to affects males more (hemophilia, colour blindness) (b) X-linked recessive is characterised by skips generations, carriers possible (c) autosomal dominant — every affected person has an affected parent (d) consanguinity has no role in pedigree analysis
Solution — Step by Step
This option swaps the definitions. autosomal recessive is actually skips generations, carriers possible, not what (a) claims. So (a) is out.
Similarly, X-linked recessive means affects males more (hemophilia, colour blindness). Option (b) is mismatched. Out.
This one reads correctly: autosomal dominant — every affected person has an affected parent. Match with NCERT wording confirms it.
consanguinity — marked with a double horizontal line — plays a real role in pedigree analysis, so option (d) is factually wrong.
Correct answer: (c) autosomal dominant — every affected person has an affected parent.
Why This Works
NEET PYQs on pedigree analysis rely on definition swapping. The examiner takes two correct facts and pairs them with the wrong terms. If you know each fact cold, the MCQ dissolves in 20 seconds.
Alternative Method
For definition-swap MCQs, don’t read all four options first. Read option (a), decide true/false, then (b), and so on. This prevents confusion between similar-looking options.
NEET reuses the same fact set every 2–3 years with different distractors. Master the four NCERT facts on pedigree analysis listed here and you’ll handle almost any MCQ on this chapter.
Common Mistake
Students second-guess themselves when they see a familiar option listed as “wrong” in the stem. Trust the elimination — if you know the definition, stick with it.
Keep a one-page sheet of definitions for every NEET chapter. Revise only that sheet in the last 48 hours before the exam.