The shorter and longer arms of a submetacentric chromosome are referred to as
Answer: (B) p-arm and q-arm respectively. Answer: (B) p-arm and q-arm respectively Solution: A sub-metacentric chromosome has its centromere slightly away from the middle, giving one shorter arm and one longer arm.
- A.s-arm and l-arm respectively
- B.p-arm and q-arm respectively✓
- C.q-arm and p-arm respectively
- D.m-arm and n-arm respectively
Correct Answer
(B) p-arm and q-arm respectively
Solution & Explanation
Answer: (B) p-arm and q-arm respectively Solution: A sub-metacentric chromosome has its centromere slightly away from the middle, giving one shorter arm and one longer arm. By convention these are designated the p-arm (shorter, 'petit') and the q-arm (longer). NCERT describes the shorter and longer arms of the sub-metacentric chromosome but does not formally name them p/q; the standard cytogenetic nomenclature gives the keyed answer. NCERT Reference: Ch 8, p.101, lines 25-28: "The sub-metacentric chromosome has centromere slightly away from the middle of the chromosome resulting into one shorter arm and one longer arm."