10. Muscle that is essential for maintenance of posture in the sitting and standing position is:
[UPPSC LT Grade Assistant Teacher (Home Science), 29 July 2018]
(a) Skeletal muscle
(b) Smooth muscle
(c) Cardiac muscle
(d) None of the above
Answer: (a) Skeletal muscle
Explanation: Postural skeletal muscles maintain alignment of the head, trunk and limbs against gravity. Their continuous low-level activity, controlled by nervous reflexes and motor pathways, stabilizes standing and sitting positions. Smooth and cardiac muscles do not provide this principal postural function.
9. How many pairs of ribs are there in the human body?
[SSC CGL, 12 August 2017, Shift 2]
(a) 13
(b) 11
(c) 12
(d) 14
Answer: (c) 12
Explanation: The thoracic cage normally includes twelve pairs of ribs, making twenty-four ribs. Pairs one to seven attach directly to the sternum through their own costal cartilages, pairs eight to ten indirectly, and pairs eleven and twelve are floating.
8. A muscle that is consciously controlled is:
[WBCS Prelims 2016]
(a) Striated voluntary
(b) Striated involuntary
(c) Non-striated voluntary
(d) Non-striated involuntary
Answer: (a) Striated voluntary
Explanation: Skeletal muscles are usually both striated and voluntary. Their contractions can be initiated consciously, for example while walking or lifting objects. Smooth muscles are typically non-striated and involuntary, whereas heart muscle is striated but involuntary.
7. Which one of the following salts is found in the maximum amount in human bones?
[UPPCS Mains 2015]
(a) Magnesium chloride
(b) Calcium carbonate
(c) Calcium phosphate
(d) Sodium chloride
Answer: (c) Calcium phosphate
Explanation: The predominant inorganic bone mineral is calcium phosphate in the crystalline form of hydroxyapatite. These deposits confer rigidity and compressive strength. Collagen supplies an organic scaffold and tensile resilience, so healthy bone combines mineral hardness with structural flexibility.
6. The most abundant element found in the human body is:
[UPPCS Mains 2014]
(a) Iron
(b) Sodium
(c) Oxygen
(d) Iodine
Answer: (c) Oxygen
Explanation: Oxygen accounts for the largest proportion of body mass because it occurs abundantly in water and many biological compounds. Calcium and phosphorus, though less abundant overall, are especially important in skeletal mineralization and the structural strength of bones.
5. Consider the following minerals:
1. Calcium
2. Iron
3. Sodium.
Which are required by the human body for contraction of muscles?
[UPSC Civil Services Prelims 2013]
(a) 1 only
(b) 2 and 3 only
(c) 1 and 3 only
(d) 1, 2 and 3
Answer: (d) 1, 2 and 3
Explanation: Calcium triggers actin-myosin interaction, sodium supports membrane excitability and nerve impulses, while iron contributes to oxygen handling through myoglobin and other proteins. The examination recognizes all three as necessary for normal muscle function, even though their roles differ.
4. Match the bones with their anatomical names:
A. Breastbone
B. Collarbone
C. Kneecap
D. Shoulder blade;
1. Clavicle
2. Patella
3. Scapula
4. Sternum.
[RPSC RAS Prelims 2013]
(a) A-1, B-3, C-2, D-4
(b) A-1, B-2, C-3, D-4
(c) A-4, B-1, C-2, D-3
(d) A-4, B-1, C-3, D-2
Answer: (c) A-4, B-1, C-2, D-3
Explanation: Sternum is the breastbone, clavicle is the collarbone, patella is the kneecap and scapula is the shoulder blade. These recognizable skeletal landmarks belong to the thoracic cage, pectoral girdle and knee region, respectively.
3. Which of the following are required for the formation of bones and teeth?
[UPPCS Mains 2011]
(a) Sodium and potassium
(b) Iron and calcium
(c) Sodium and calcium
(d) Calcium and phosphorus
Answer: (d) Calcium and phosphorus
Explanation: Calcium and phosphorus are the principal mineral constituents of hydroxyapatite, the hard crystalline material of bones and tooth enamel. Adequate intake and vitamin D regulation support mineralization, while the collagen framework gives growing bone its shape and toughness.
2. The strongest muscle in the human body is found in:
[UPPCS Mains 2008]
(a) Jaws
(b) Thighs
(c) Neck
(d) Hands
Answer: (a) Jaws
Explanation: The examination refers to the masseter, a powerful jaw-closing muscle producing very high bite force relative to its size. Strongest can mean different measurements; the gluteus maximus is largest by volume and the sartorius is longest.
1. What is arthroplasty in surgery?
[Uttar Pradesh UDA/LDA Prelims 2002]
(a) Open-heart surgery
(b) Kidney transplant
(c) Hip-joint replacement
(d) Blood transfusion
Answer: (c) Hip-joint replacement
Explanation: Arthroplasty means surgical reconstruction or replacement of a joint. Hip-joint replacement is a major example, usually involving prosthetic components replacing damaged articular surfaces. The procedure aims to relieve pain and improve movement in severe joint disease.
Question years and examination labels follow the cited exam-paper compilations and the uploaded reference. Explanations are independently written. No practice questions or source links are included.
