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.
