60. Which of the following elements of the human skeletal framework is classified as the smallest individual bone in the human body?
[SSC Selection Post (Graduate), 17 September 2026, Shift 1]
(a) Scapula bone
(b) Rib cage
(c) Stapes bone
(d) Coxal bone
Answer: (c) Stapes bone
Explanation: The stapes is a tiny stirrup-shaped auditory ossicle in the middle ear. It conveys vibrations from the incus to the oval window. In contrast, the femur is the longest human bone, while the rib cage comprises multiple bones.
59. A football player tears a structure that connects muscles to bones during practice. Which structure is most likely damaged?
[RRB Group D, 18 August 2026, Shift 3]
(a) Tendon
(b) Ligament
(c) Cartilage
(d) Nerve
Answer: (a) Tendon
Explanation: Tendons are strong collagen-rich bands attaching skeletal muscles to bones. They transmit muscular pulling force to produce joint movement. Ligaments instead connect bones to other bones, while cartilage cushions and supports joints and nerves carry electrical signals.
58. The cells of the cartilage are known as ________.
[RRB Group D, 9 August 2026, Shift 2]
(a) Fibroblasts
(b) Osteocytes
(c) Chondrocytes
(d) Adipocytes
Answer: (c) Chondrocytes
Explanation: Chondrocytes are mature cartilage cells situated in spaces called lacunae. They manufacture and maintain a matrix rich in collagen and proteoglycans. Osteocytes maintain bone, fibroblasts make connective-tissue fibres, and adipocytes mainly store fat.
57. Smooth muscles are responsible for all the following actions, EXCEPT:
[RRB Group D, 6 August 2026, Shift 2]
(a) Lifting a heavy bucket of water
(b) Regular movements in the intestines
(c) Moving food through the digestive tract
(d) Functioning automatically without conscious thought
Answer: (a) Lifting a heavy bucket of water
Explanation: Lifting a heavy bucket primarily recruits voluntary skeletal muscles, including muscles of the arms, shoulders and trunk. Smooth muscles are involuntary and produce rhythmic intestinal movements and peristalsis. Their contraction is controlled mainly by autonomic mechanisms.
56. Which of the following correctly differentiates ligament from tendon in human connective tissue?
[RRB Technician Grade III, 10 March 2026, Shift 1]
(a) Ligament connects bone to bone; tendon connects muscle to bone
(b) Both ligament and tendon connect bones to bones but differ in colour
(c) Ligament connects muscle to bone, while tendon connects bone to bone
(d) Tendon is elastic, while ligament is completely non-elastic
Answer: (a) Ligament connects bone to bone; tendon connects muscle to bone
Explanation: Ligaments stabilize a joint by linking adjacent bones. Tendons link muscles to bones and transmit contractile force. Both contain collagen, but their arrangement and elasticity vary according to function. Reversing their anatomical connections is a common examination trap.
55. Which type of action is heartbeat?
[SSC GD Constable, 29 April 2026, Shift 1]
(a) Reflex action
(b) Involuntary action
(c) Voluntary action
(d) Coordinated action
Answer: (b) Involuntary action
Explanation: Heartbeat occurs without conscious direction because cardiac muscle contracts rhythmically through its intrinsic pacemaker system. The autonomic nervous system modifies its rate and strength. Unlike skeletal muscles used for deliberate movements, the myocardium operates automatically throughout life.
54. In humans, rings of cartilage are present in the ___.
[SSC MTS, 5 February 2026, Shift 3]
(a) Stomach
(b) Mouth
(c) Ear
(d) Throat
Answer: (d) Throat
Explanation: The trachea, passing through the neck or throat, is supported by C-shaped hyaline cartilage rings. They prevent airway collapse during breathing while leaving the posterior wall flexible enough to accommodate expansion of the adjacent oesophagus during swallowing.
53. What is the role of peristaltic movements in the human digestive system?
[RRB Group D, 10 February 2026, Shift 2]
(a) To produce digestive enzymes
(b) To digest proteins in the stomach
(c) To absorb nutrients into the blood
(d) To push food forward along the digestive tract
Answer: (d) To push food forward along the digestive tract
Explanation: Peristalsis consists of coordinated waves of contraction and relaxation in smooth muscle layers of the digestive tract. These involuntary movements propel food and chyme forwards. They are distinct from enzyme secretion, chemical digestion and intestinal nutrient absorption.
52. Which type of muscular tissue is present in the wall of the stomach?
[RRB Group D, 26 December 2025, Shift 3]
(a) Smooth muscle tissue
(b) Skeletal muscle tissue
(c) Cardiac muscle tissue
(d) Fluid connective tissue
Answer: (a) Smooth muscle tissue
Explanation: The stomach wall contains layers of involuntary smooth muscle that churn food and mix it with gastric secretions. Skeletal muscle generally produces voluntary body movements; cardiac muscle forms the heart wall. Smooth muscle cells lack the obvious striations of skeletal muscle.
51. Which of the following axial skeleton pairs in humans is NOT correctly matched?
[DSSSB TGT Natural Science, 6 September 2025, Shift 2]
(a) Facial bones – Mandible
(b) Thoracic cage – Sternum
(c) Auditory ossicles – Sacrum
(d) Cranial bones – Parietal
Answer: (c) Auditory ossicles – Sacrum
Explanation: The sacrum is a fused bone at the lower end of the vertebral column, not an auditory ossicle. The auditory ossicles are the malleus, incus and stapes in each middle ear. The other listed anatomical pairings are correct.
50. Which type of muscles do the uterus, iris of the eye, and bronchi contain?
[SSC Selection Post (Matriculation), 20 June 2024, Shift 1]
(a) Smooth muscles
(b) Striated muscles
(c) Skeletal muscles
(d) Cardiac muscles
Answer: (a) Smooth muscles
Explanation: The uterus, iris and bronchi contain smooth muscle, whose actions generally occur without conscious control. Uterine contractions, changes in pupil diameter and bronchial calibre depend upon smooth-muscle activity. Cardiac muscle is confined to the heart and skeletal muscle moves bones.
49. The joint where the neck joins the head is:
[UPPSC PCS Prelims, General Studies Paper I, 2024]
(a) Saddle joint
(b) Hinge joint
(c) Pivotal joint
(d) Ball and socket joint
Answer: (c) Pivotal joint
Explanation: The expected examination answer is the pivot joint. More precisely, rotation of the head occurs at the atlanto-axial joint between the atlas and axis vertebrae. The neighbouring atlanto-occipital joint chiefly permits nodding and is anatomically a condylar joint.
48. In which part or organ of the human body is cartilage NOT found?
[UPSC NDA-II General Ability Test, 1 September 2024]
(a) Nose
(b) Trachea
(c) Bronchiole
(d) Knee joint
Answer: (c) Bronchiole
Explanation: Bronchioles lack cartilage in their walls and depend substantially on surrounding tissue and smooth muscle for support. Cartilage occurs in the nose, the C-shaped tracheal rings and the articular surfaces of the knee, where it reduces friction.
47. Which one among the following tissues helps to connect two bones?
[UPSC NDA-II General Ability Test, 1 September 2024]
(a) Tendons
(b) Ligaments
(c) Areolar tissue
(d) Cartilage
Answer: (b) Ligaments
Explanation: Ligaments are tough fibrous connective-tissue bands that join bone to bone and stabilize joints. Tendons join muscle to bone, while areolar tissue fills spaces and binds tissues. Articular cartilage provides a smooth, cushioning surface rather than acting as the primary bone-to-bone tie.
46. The axial skeleton is comprised of:
[Rajasthan CHO, 3 March 2024]
(a) Skull and vertebral column
(b) Vertebral column, ribs and sternum
(c) Skull, vertebral column, ribs and sternum
(d) Skull, vertebral column and ribs
Answer: (c) Skull, vertebral column, ribs and sternum
Explanation: The axial skeleton forms the central framework and includes the skull, vertebral column, ribs and sternum, together with associated hyoid and auditory ossicles. It supports posture and protects the brain, spinal cord and vital organs of the thorax.
45. Ribs are attached to which of the following structures?
[CGPSC Laboratory Assistant (Forensic Department), 25 August 2024, paper transcription]
(a) Scapula
(b) Clavicle
(c) Ilium
(d) Sternum
Answer: (d) Sternum
Explanation: Ribs articulate posteriorly with thoracic vertebrae, while anterior attachment to the sternum occurs through costal cartilage in the true ribs. The scapula belongs to the shoulder girdle, the clavicle to the collar region and the ilium to the pelvis.
44. Which one among the following diseases is caused due to deficiency of Vitamin D in humans?
[UPSC NDA-II General Ability Test, 1 September 2024]
(a) Beriberi
(b) Scurvy
(c) Rickets
(d) Pneumonia
Answer: (c) Rickets
Explanation: Vitamin D promotes intestinal absorption of calcium and phosphate required for mineralization of developing bone. Deficiency in children produces rickets, often with bowed legs or delayed growth; defective mineralization in adults is called osteomalacia.
43. Which among the following is a flat bone?
[SSC CHSL Tier I, 20 March 2023, Shift 1]
(a) Ankle bones
(b) Pelvic bones
(c) Wrist bones
(d) Ribs
Answer: (d) Ribs
Explanation: Ribs are flattened, curved bones that help form the protective thoracic cage. Their form supplies broad attachment areas for muscles and shields the heart and lungs. Wrist carpals and ankle tarsals are usually classified as short bones.
42. Which of the following is a type of connective tissue? I. Blood II. Bone III. Ligament
[SSC CHSL Tier I, 17 March 2023, Shift 2]
(a) Only III
(b) Only II and III
(c) I, II and III
(d) Only I and III
Answer: (c) I, II and III
Explanation: Blood is fluid connective tissue, bone is mineralized supportive connective tissue, and ligaments are dense fibrous connective tissue. Though their appearance varies greatly, all contain cells within a matrix and perform binding, support, defence or transport functions.
41. A sprinter feels cramps and pain in the thigh muscles after a run. This is due to accumulation of:
[UPSC CDS-I General Knowledge, 16 April 2023]
(a) Lactic acid
(b) Carbon dioxide
(c) Pyruvic acid
(d) Ethanol
Answer: (a) Lactic acid
Explanation: The conventional examination answer is lactic acid, produced during intense exercise when anaerobic glycolysis becomes prominent. Modern physiology notes that fatigue and cramping involve several mechanisms, so lactate itself should not be considered the sole direct cause of cramps.
40. The type of joint (pivot) between Atlas and Axis is known as:
[MPPSC State Services Prelims 2022 cycle, held 21 May 2023]
(a) Saddle joint
(b) Fibrous joint
(c) Cartilaginous joint
(d) Synovial joint
Answer: (d) Synovial joint
Explanation: The atlanto-axial articulation is a pivot-type synovial joint. The dens of the axis allows the atlas and head to rotate around a vertical axis. A synovial cavity, joint capsule and associated ligaments support this movement.
39. Insufficient levels of parathyroid hormone and a low amount of calcium in the blood cause which of the following conditions?
[SSC MTS, 4 September 2023, Shift 3]
(a) Malaria
(b) Anaemia
(c) Diabetes
(d) Hypocalcaemia
Answer: (d) Hypocalcaemia
Explanation: Hypocalcaemia means reduced calcium concentration in the blood. Inadequate parathyroid hormone can lower serum calcium through effects on bone, kidneys and vitamin D activation. Severe deficiency may produce tingling, muscle spasms, tetany and abnormal neuromuscular excitability.
38. Which of the following is known as bodybuilding food?
[SSC CGL Tier I, 20 July 2023, Shift 4]
(a) Fats
(b) Carbohydrates
(c) Proteins
(d) Vitamins
Answer: (c) Proteins
Explanation: Proteins supply amino acids needed to build and repair body tissues, especially muscle proteins following growth or exercise. Carbohydrates mainly supply fuel, fats provide concentrated energy and membrane components, while vitamins support regulation of numerous metabolic reactions.
37. Which of the following statements is INCORRECT about voluntary muscles?
[RRB Group D, 15 September 2022, Shift 3]
(a) Cells are long, cylindrical, unbranched and uninucleate
(b) These muscles are also called skeletal muscles
(c) These muscles show alternate light and dark bands
(d) They are mostly attached to bones
Answer: (a) Cells are long, cylindrical, unbranched and uninucleate
Explanation: Skeletal muscle fibres are elongated, cylindrical, unbranched and typically multinucleated, so calling them uninucleate is incorrect. Their regular arrangement of actin and myosin creates visible striations. They are mainly attached to bones and enable voluntary movements.
36. Movement in most animals is a coordinated activity of which of the following system/systems?
[RRB Group D, 22 August 2022, Shift 1]
(a) Only muscular system
(b) Only skeletal and nervous systems
(c) Only nervous system
(d) Muscular, skeletal and nervous systems
Answer: (d) Muscular, skeletal and nervous systems
Explanation: Animal locomotion depends on muscles generating force, skeletal elements providing leverage and support, and nerves coordinating contraction. None of these systems alone can produce normal deliberate movement. Sensory feedback additionally helps regulate posture, timing and direction.
35. Which of the following is primarily responsible for the movement of the human body?
[RRB Group D, 26 September 2022, Shift 3]
(a) Combination of nervous and connective tissues
(b) Combination of nervous and epithelial tissues
(c) Combination of muscular and connective tissues
(d) Combination of nervous and muscular tissues
Answer: (d) Combination of nervous and muscular tissues
Explanation: Nervous tissue conducts the signals that activate motor units, while muscle tissue contracts to produce physical movement. Connective structures such as tendons and bones transmit these forces. The option emphasizes the functional partnership between neural control and muscular action.
34. Bone cells are embedded in a hard matrix that is composed of ________________.
[RRB Group D, 19 September 2022, Shift 3]
(a) Phosphorus and potassium
(b) Fluoride and calcium
(c) Potassium and calcium
(d) Calcium and phosphorus
Answer: (d) Calcium and phosphorus
Explanation: Bone owes much of its rigidity to calcium-phosphate mineral deposited as hydroxyapatite around a collagen-rich organic matrix. Osteocytes occupy small lacunae within this structure. Calcium and phosphate together provide strength, while collagen supplies toughness and resistance to fracture.
33. In which of the following is cartilage NOT present?
[RRB Group D, 15 September 2022, Shift 2]
(a) Kidney
(b) Nose
(c) Larynx
(d) Ear
Answer: (a) Kidney
Explanation: The nose, external ear and larynx contain supportive cartilage, although of different types and shapes. Kidneys do not normally contain cartilage; their specialized architecture consists mainly of nephrons, blood vessels, epithelial structures and supporting interstitial tissue.
32. What is the difference between striated and smooth muscle cells?
[RRB Group D, 12 September 2022, Shift 2]
(a) All striated muscles work by reflex action as compared to smooth muscles
(b) Striated muscles lack nuclei while smooth muscles are binucleated
(c) Smooth muscles are not connected to the nerves while striated muscles are connected
(d) Smooth muscles cannot contract at will, while voluntary muscles contract at will
Answer: (d) Smooth muscles cannot contract at will, while voluntary muscles contract at will
Explanation: Smooth muscles usually function involuntarily in the walls of organs and vessels. Skeletal or voluntary striated muscles are controlled consciously through somatic motor pathways. Smooth muscle cells are generally spindle-shaped and uninucleate; skeletal fibres are typically multinucleate.
31. What is the cause of muscle cramps?
[RRB Group D, 17 September 2022, Shift 2]
(a) Low glucose level in the blood (hypoglycaemia)
(b) Excessive excitation of neuromuscular junctions
(c) Insufficiency of oxygen supply to muscles
(d) Fatigue and weakness of the body
Answer: (c) Insufficiency of oxygen supply to muscles
Explanation: The cited examination attributes exercise-associated cramping to inadequate oxygen supply and increased anaerobic metabolism in muscles. In clinical physiology, cramps are multifactorial and may also reflect altered neuromuscular control, fatigue and electrolyte disturbances.
30. The presence of which of the following does NOT let the air passage in the respiratory system of humans collapse when there is less air in it?
[RRB Group D, 6 September 2022, Shift 1]
(a) Tendons
(b) Ligaments
(c) Rings of cartilage
(d) Muscles
Answer: (c) Rings of cartilage
Explanation: C-shaped rings of hyaline cartilage reinforce the trachea and help keep its lumen open despite pressure changes during breathing. Their incomplete posterior portion also allows expansion of the oesophagus during swallowing. Ligaments and tendons perform different supportive roles.
29. Which of the following tissues helps in tissue repair?
[RRB Group D, 16 September 2022, Shift 3]
(a) Tendon
(b) Ligament
(c) Areolar
(d) Cartilage
Answer: (c) Areolar
Explanation: Areolar tissue is loose connective tissue found between organs, around vessels and beneath epithelia. Fibroblasts in this tissue produce repair-associated extracellular matrix, and immune cells participate in healing. Dense tendon and ligament tissue generally heal more slowly.
28. Where in a human body can anaerobic respiration take place?
[RRB Group D, 30 September 2022, Shift 2]
(a) Only in striated muscle cells
(b) In the cytoplasm of cells
(c) In mitochondria of all cells
(d) Only in red blood cells in the veins
Answer: (b) In the cytoplasm of cells
Explanation: Glycolysis occurs in the cytoplasm, where ATP can be produced without oxygen. During intense muscle activity, pyruvate may be converted to lactate, regenerating NAD+ needed for glycolysis. Anaerobic ATP generation is not restricted exclusively to skeletal muscle.
27. How many bones form the axial skeleton?
[NVS Staff Nurse, 8 March 2022]
(a) 126 bones
(b) 80 bones
(c) 206 bones
(d) 70 bones
Answer: (b) 80 bones
Explanation: The adult axial skeleton contains 80 bones, including cranial and facial bones, auditory ossicles, hyoid, vertebral column, ribs and sternum. The appendicular skeleton contributes 126 bones of the limbs and girdles, together giving the standard total of 206.
26. Which of the following connects a bone to bone?
[WBCS Mains 2021 cycle, Paper IV, held May 2022]
(a) Cartilage
(b) Ligament
(c) Tendon
(d) Interstitial fluid
Answer: (b) Ligament
Explanation: A ligament connects adjacent bones and stabilizes their articulation. Tendons connect muscles to bones; cartilage makes joint surfaces resilient and smooth. Joint stability depends on a combination of ligament tension, bony shape and surrounding muscle control.
25. Which is the largest joint in the human body?
[RRB NTPC CBT I, 5 April 2021, Shift 2]
(a) Knee joint
(b) Neck joint
(c) Pelvic joint
(d) Shoulder joint
Answer: (a) Knee joint
Explanation: The knee is the largest joint in the human body and bears substantial weight during walking, running and jumping. It joins the femur and tibia, with the patella positioned anteriorly, and incorporates menisci, ligaments and synovial fluid.
24. There are 29 bones in the human head. Which of the following classifications is correct?
[RRB NTPC CBT I, 3 April 2021, Shift 1]
(a) Cranial-8, Facial-14, Ear-6, Hyoid-1
(b) Cranial-8, Facial-12, Ear-6, Hyoid-3
(c) Cranial-8, Facial-14, Ear-4, Hyoid-3
(d) Cranial-8, Facial-12, Ear-8, Hyoid-1
Answer: (a) Cranial-8, Facial-14, Ear-6, Hyoid-1
Explanation: Counting the skull with associated ear ossicles and hyoid gives 29 bones: eight cranial, fourteen facial, six middle-ear ossicles and one hyoid. The anatomical skull itself is commonly described as twenty-two bones, excluding ossicles and hyoid.
23. Which is the smallest bone of the human body?
[RRB NTPC CBT I, 8 March 2021, Shift 1]
(a) Femur
(b) Stapes
(c) Humerus
(d) Malleus
Answer: (b) Stapes
Explanation: The stapes is the smallest of the auditory ossicles in the middle ear. Its footplate transfers mechanical vibrations to the oval window of the inner ear. The femur is the longest bone, while the humerus belongs to the upper arm.
22. The number of bones in an adult human body is:
[RRB NTPC CBT I, 9 January 2021, Shift 2]
(a) 206
(b) 156
(c) 16
(d) 296
Answer: (a) 206
Explanation: The conventional adult skeleton consists of 206 bones, partitioned into 80 axial and 126 appendicular elements. Babies have more separately developing skeletal parts because some bones later fuse. Individual adult counts can vary because of accessory bones.
21. The smallest and longest bones in the human body are ________ and _________, respectively.
[SSC GD Constable, 26 November 2021, Shift 3]
(a) Stapes, fibula
(b) Tibia, femur
(c) Stapes, femur
(d) Nails, fibula
Answer: (c) Stapes, femur
Explanation: The stapes is a minute bone in the middle ear involved in hearing. The femur, extending from hip to knee, is the longest and among the strongest bones. The fibula is a smaller long bone of the lower leg.
20. The fluid present between joints, that makes the movement of joints easy, is called:
[SSC MTS 2020 cycle, held 8 October 2021, Shift 3]
(a) Tendon
(b) Synovial
(c) Cartilage
(d) Bursae
Answer: (b) Synovial
Explanation: Synovial fluid lubricates freely movable joints, reducing friction between articular surfaces. It also helps nourish avascular articular cartilage. The fluid is secreted by synovial membrane, while bursae are separate fluid-filled sacs that reduce friction near joint structures.
19. Which of the following is NOT a synovial joint in the human body?
[SSC MTS 2020 cycle, held 18 October 2021, Shift 3]
(a) Suture joint
(b) Ball-and-socket joint
(c) Hinge joint
(d) Condyloid joint
Answer: (a) Suture joint
Explanation: Skull sutures are fibrous, normally immovable joints and lack synovial cavities. Ball-and-socket, hinge and condyloid joints are types of synovial joints, which permit controlled movement through articular cartilage, lubricating fluid, capsules and supporting ligaments.
18. Which of the following is not a bone in babies at birth?
[SSC GD Constable, 1 December 2021, Shift 1]
(a) Pelvic
(b) Collar
(c) Cheek
(d) Kneecap
Answer: (d) Kneecap
Explanation: The kneecap or patella is largely cartilaginous at birth rather than a fully ossified bone. Ossification begins later in childhood. This developmental pattern explains why newborn skeletal structures differ from those of adults and why several elements eventually fuse.
17. A fibrous connective tissue that attaches bone to bone is called:
[SSC Junior Engineer (Mechanical), 27 October 2020, Evening]
(a) Ligament
(b) Tendon
(c) Vein
(d) Artery
Answer: (a) Ligament
Explanation: A ligament is dense collagen-rich connective tissue spanning two bones. Its primary role is to support and stabilize joints and limit excessive motion. A tendon attaches muscle to bone, whereas veins and arteries are blood vessels, not skeletal attachments.
16. Which of the following is the largest bone in the human body?
[SSC CHSL, 4 July 2019, Shift 2]
(a) Femur
(b) Incus
(c) Malleus
(d) Stapes
Answer: (a) Femur
Explanation: The femur forms the bony framework of the thigh and is the largest as well as longest bone in adults. It transmits body weight from hip to knee. The other three options name much smaller middle-ear ossicles.
15. In which part of the body is blood produced?
[SSC CGL, 13 June 2019, Shift 2]
(a) Lungs
(b) Heart
(c) Brain
(d) Bone marrow
Answer: (d) Bone marrow
Explanation: Bone marrow contains hematopoietic stem cells that generate red blood cells, white blood cells and platelets. In adults, much active red marrow is found in the pelvis, vertebrae, sternum, ribs and ends of certain long bones.
14. Identify the largest muscle in the human body.
[SSC CPO Tier I, 14 March 2019, Shift 1]
(a) Sartorius
(b) Iliopsoas
(c) Gluteus maximus
(d) Latissimus dorsi
Answer: (c) Gluteus maximus
Explanation: Gluteus maximus is regarded as the largest human skeletal muscle by bulk. It powerfully extends and laterally rotates the hip, especially when rising, climbing or running. Sartorius, by contrast, is notable for being the longest muscle.
13. Muscle fatigue is due to accumulation of:
[WBCS Prelims 2018]
(a) Carbon dioxide
(b) Creatinine
(c) Lactic acid
(d) Ethyl alcohol
Answer: (c) Lactic acid
Explanation: Lactic acid accumulation is the conventional answer used in this examination for fatigue during strenuous work. Current exercise physiology recognises multiple contributing processes, including altered ion balance and energy availability; lactate production can also help sustain muscular ATP generation.
12. The _________ has abundant white fibres.
[RRB ALP, 20 August 2018, Shift 1]
(a) Cartilage
(b) Bone
(c) Tendon
(d) Ligament
Answer: (c) Tendon
Explanation: Tendons contain abundant densely packed white collagen fibres aligned with the direction of force. This construction makes them exceptionally strong in tension. Their main function is transmitting skeletal-muscle pull to bones while allowing little stretch compared with elastic tissue.
11. ______ tissue changes the diameter of a blood vessel.
[RRB ALP, 30 August 2018, Shift 1]
(a) Heart
(b) Muscle
(c) Epithelial
(d) Bone
Answer: (b) Muscle
Explanation: Smooth muscle in the tunica media of blood vessels changes their diameter through contraction and relaxation. Vasoconstriction increases resistance, whereas vasodilation reduces it. Epithelial linings, bones and cardiac tissue do not directly perform this vascular adjustment.
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.
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