MPSC 2024 Prelims Paper-I · Question 64 of 100

Correct — option (2), 'Only (b)'. Only two statements are printed here, so the whole question turns on settling each of them. Statement (a) says the adult human skeleton consists of 208 bones, and that is wrong: the standard count is 206. The figure is worth holding as its two halves, because that is how it is usually tested — the axial skeleton has 80 bones, made up of the skull with 22, the six ear ossicles, the single hyoid, the vertebral column with 26, the sternum and the 24 ribs; the appendicular skeleton has 126, made up of 30 bones in each limb, four in the pectoral girdle and two in the pelvic girdle. Eighty and 126 give 206. A newborn has many more, of the order of three hundred separate elements, and the number falls to 206 in adulthood as bones such as those of the sacrum, the coccyx and the hip bone fuse; that is exactly why the statement specifies the adult skeleton, and why an inflated figure looks superficially reasonable. Statement (b) says vertebrae and facial bones are of the irregular type, and that is right. Bones are classified by shape into long, short, flat, irregular and sesamoid, and the irregular class is the one reserved for bones of complicated shape that fit none of the others — the vertebrae, with their body, arch and several processes, and the bones of the face, are its standard examples. Since statement (a) is false and statement (b) is true, the option that names statement (b) alone is the answer.

• (1)(a) & (b) — This option accepts both statements, and it fails on the number alone. The adult human skeleton has 206 bones, not 208, and the figure is one of the few in human anatomy that examinations expect to be known exactly. A candidate who chooses this option has usually recognised the truth of the second statement — which is genuinely correct — and then let it carry the first, which is the standard failure in a two-statement question: each statement must be settled on its own before any option is read.
• (3)(a) only — This option keeps the false statement and rejects the true one, so it is wrong twice. The count of 208 is not the accepted figure, and the classification of vertebrae and facial bones as irregular bones is standard: irregular is precisely the category created for bones whose shape is too complex to be called long, short or flat. Anyone selecting this has probably misremembered the total as 208 and then, being confident of it, doubted the shape classification unnecessarily.
• (4)Neither of the two — Rejecting both statements is right about the first and wrong about the second. Vertebrae and facial bones genuinely are irregular bones, so a blanket rejection cannot stand. This option tempts a candidate who has correctly spotted that 208 is not the right number and then assumes that a question printing one false statement must be printing two — an assumption the format never justifies. An escape option of this kind is only safe when every printed statement has been positively disproved.

The human skeleton is described in two ways at once, and both are examinable. By division it is axial and appendicular: the axial skeleton, of 80 bones, is the skull with 22 bones, the six ear ossicles, the hyoid, the vertebral column of 26 bones, the sternum and the 24 ribs, and the appendicular skeleton, of 126 bones, is the two limbs with 30 bones each and their girdles, four in the pectoral and two in the pelvic, giving 206 in all in the adult. By shape it is classified into five types: long bones such as the humerus and femur, in which length exceeds breadth and which act as levers; short bones such as the carpals and tarsals, roughly cubical and built for stability; flat bones such as the sternum, the ribs, the scapula and the bones of the cranial vault, which protect underlying organs and provide broad surfaces for muscle attachment; irregular bones such as the vertebrae and the bones of the face, whose complex shape suits them to no other category; and sesamoid bones, which develop within tendons, the patella being the largest. The count of 206 applies only to the adult, because a newborn's skeleton contains a far larger number of separate elements that later fuse — the five sacral vertebrae into the sacrum, the coccygeal into the coccyx, and the ilium, ischium and pubis into a single hip bone on each side.

MPSC's human physiology questions are dominated by exact counts and by classifications, because both can be tested in a single line and marked without ambiguity. The counts worth memorising are 206 bones in all, 80 axial and 126 appendicular, 22 in the skull, 26 in the vertebral column and 12 pairs of ribs; the classifications worth memorising are the five shape types with one example each. This question shows why a two-statement item is easier than a four-statement one but no less exacting: with only two statements, every option corresponds to a distinct verdict on the pair, so a single misjudged statement decides the mark. The discipline is to write a tick or a cross against each printed statement before looking at the options, and to notice that the paper here prints only two statements — there is no statement (c) or (d) to argue about.

• The adult human skeleton has 206 bones, not 208; the number is higher at birth and falls as bones such as the sacrum, coccyx and hip bone fuse.
• The axial skeleton contributes 80 bones — skull 22, ear ossicles 6, hyoid 1, vertebral column 26, sternum 1, ribs 24 — and the appendicular skeleton 126.
• Bones are classified by shape into long, short, flat, irregular and sesamoid types.
• Vertebrae and the bones of the face are the standard examples of irregular bones, their shape being too complex for any other category.
• The patella, which develops within the tendon of the thigh muscles, is the largest sesamoid bone.

• Accepting a near-miss figure such as 208 for the adult bone count; the accepted number is 206
• Letting a true second statement carry a false first one in a two-statement question
• Confusing the adult count with the far larger number of bones present at birth, many of which later fuse
• Classifying vertebrae as short or flat bones; they are the standard example of the irregular type

Skeletal-system questions in MPSC papers turn on exact numbers and on shape classification, and they often print a figure that is close to the right one rather than wildly wrong, so approximate memory is not enough. The two-statement format seen here appears throughout this paper and is best handled by verdict-first reading: settle each statement independently, then find the option that matches the pair of verdicts. Expect companion questions on the number of vertebrae in each region of the spine, the number of pairs of ribs and their division into true, false and floating, and the identification of the longest, smallest and largest bones.

No directly related past PYQ was found.

• practice — not a real PYQ

  How many bones does the axial skeleton of an adult human contain ?

  • (a)80
  • (b)126
  • (c)206
  • (d)22

  Answer(a) 80 — the axial skeleton comprises the skull with 22 bones, the six ear ossicles, the hyoid, the vertebral column of 26 bones, the sternum and 24 ribs. The appendicular skeleton accounts for the remaining 126 of the adult total of 206, and 22 is the number of bones in the skull alone.

• practice — not a real PYQ

  The patella is an example of which type of bone ?

  • (a)Long bone
  • (b)Flat bone
  • (c)Irregular bone
  • (d)Sesamoid bone

  Answer(d) Sesamoid bone — the patella develops within the tendon of the thigh muscles and is the largest bone of that type. Vertebrae and facial bones are the standard irregular bones, the sternum and scapula are flat bones, and the femur is the classic long bone.