Match List - I with List - II.
| List - I | List - II |
|---|---|
| (A) Down's syndrome | (I) 44+XX/XY |
| (B) Klinefelter's syndrome | (II) 44+XO |
| (C) Turner's syndrome | (III) 44+XXY |
| (D) Normal human | (IV) 45+XX/XY |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(IV), (B)-(III), (C)-(II), (D)-(I)
(A) Down's syndrome — this matches (IV) 45+XX/XY. An extra chromosome 21 gives 45 autosomes plus the sex chromosomes.
(B) Klinefelter's syndrome — this matches (III) 44+XXY. An extra X in a male. NCERT writes this karyotype as 47, XXY: 47 chromosomes in all, that is 44 autosomes + XXY, which is the 44 + XXY of the question.
(C) Turner's syndrome — this matches (II) 44+XO. One X missing in a female.
(D) Normal human — this matches (I) 44+XX/XY. 22 pairs of autosomes and one pair of sex chromosomes.