The number of cervical vertebrae in a human body is:
- (a)5
- (b)7
- (c)12
- (d)23
Correct — B, 7. The human vertebral column has 7 cervical vertebrae (C1–C7) in the neck region — a fixed count found in almost all mammals, including the giraffe (whose cervical vertebrae are simply far longer, not more numerous). C1 (the atlas) supports the skull, and C2 (the axis) allows the head to rotate.
- (a)5 — Too few — no mammalian cervical region, including the human one, normally has just 5 vertebrae; a handful of sloth species are the rare exception.
- (c)12 — 12 is the number of THORACIC vertebrae (one pair of ribs attaches to each) — a different region of the spine, not the cervical one.
- (d)23 — 23 is unrelated to the vertebral column; it is the well-known number of chromosome PAIRS in a human body cell (46 chromosomes total) — a different topic (genetics) entirely, planted here as a trap.
The human vertebral column (spine) has 33 vertebrae grouped into five regions: 7 cervical (neck), 12 thoracic (upper back, one pair of ribs each), 5 lumbar (lower back), 5 sacral (fused into the sacrum), and 4 coccygeal (fused into the coccyx/tailbone). Only the top 24 (7 + 12 + 5) remain separate, moveable vertebrae in an adult; the sacral and coccygeal ones fuse, so the commonly cited 'moveable spine' count is 26.
MPPSC's four options mix in genuinely different numbers from other topics (12 = thoracic vertebrae, 23 = chromosome pairs) as traps — the safest approach is to lock 'cervical = 7' as an isolated fact, kept distinct from both the thoracic/lumbar counts and from genetics entirely.
- Cervical vertebrae: 7 (C1–C7) — the same count in virtually all mammals, including giraffes and mice.
- Thoracic vertebrae: 12 (each pairs with a rib) — a common distractor for this question.
- Lumbar vertebrae: 5 (lower back).
- Sacrum (5 fused) + coccyx (4 fused) complete the 33-vertebra column; 26 remain separate/moveable in an adult.
7 cervical vertebrae is the answer here; 12 and 23 belong to entirely different counts (thoracic vertebrae, and human chromosome pairs).
- Confusing cervical vertebrae (7) with chromosome pairs (23) — both numbers are commonly placed together as MCQ options
- Confusing cervical (7) with thoracic (12) vertebrae
Pure factual recall of a fixed anatomical number; MPPSC/UPSC often pair it with an unrelated 'trap' number from genetics or another vertebral region to test precise recall rather than reasoning.
No directly related past PYQ was found on the cervical-vertebrae count; the UPSC store's chromosome/genetics questions (e.g. trisomy-21/Down syndrome) test the different, often-confused number (23 pairs) used as a distractor here.
- practice — not a real PYQ
How many thoracic vertebrae are present in the human vertebral column?
- (a)7
- (b)12
- (c)5
- (d)9
Answer(b) 12 — one for each of the 12 pairs of ribs.
- practice — not a real PYQ
Which vertebra of the human neck, called the 'atlas', directly supports the skull?
- (a)C1
- (b)C7
- (c)T1
- (d)L1
Answer(a) C1 — the atlas vertebra; C2 (the axis) allows the head to rotate.