Free Human Skeleton MCQs with Answers
138 Human Skeleton MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The human skeleton provides support, protects organs, enables movement with muscles and stores minerals while bone marrow produces blood cells. Questions cover the axial and appendicular skeleton, types of bones and joints, cartilage, ligaments and tendons, and the difference between fixed, slightly movable and freely movable joints.
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21. When a muscle fibre is stimulated, the calcium ions needed for contraction are released from the
- A. mitochondria
- B. Golgi apparatus
- C. nucleus
- D. sarcoplasmic reticulum
Explanation: The sarcoplasmic reticulum stores calcium and floods the fibre with it when an impulse arrives along the T tubules.
Correct answer: sarcoplasmic reticulum- A. a sarcomere
- B. a motor unit
- C. a reflex arc
- D. a myofibril
Explanation: All fibres of one motor unit contract together when the neuron fires, and fine muscles like those of the eye have tiny units for precise…
Correct answer: a motor unit- A. creatine phosphate
- B. glycogen only
- C. lactic acid
- D. haemoglobin
Explanation: Creatine phosphate donates its phosphate to ADP in a single step, replenishing ATP within seconds before glycogen breakdown catches up.
Correct answer: creatine phosphate- A. freely movable synovial joints
- B. slightly movable cartilaginous joints
- C. immovable fibrous joints called sutures
- D. ball and socket joints
Explanation: Sutures interlock the skull bones with fibrous tissue, locking the case that protects the brain.
Correct answer: immovable fibrous joints called sutures- A. freely movable
- B. immovable
- C. synovial
- D. slightly movable
Explanation: Cartilage discs between vertebrae allow limited movement, and the many small movements add up to the flexibility of the whole column.
Correct answer: slightly movable- A. a hinge joint
- B. a pivot joint
- C. a ball and socket joint
- D. a gliding joint
Explanation: The elbow swings in one plane, flexing and extending the forearm like a door hinge.
Correct answer: a hinge joint- A. movement in all planes
- B. rotation around a single axis
- C. gliding only
- D. no movement at all
Explanation: In a pivot joint one bone rotates within a ring formed by another, as when the atlas turns on the dens of the axis to shake the head from…
Correct answer: rotation around a single axis- A. at the hip
- B. at the elbow
- C. between the carpal bones of the wrist
- D. between the bones of the skull
Explanation: The small bones of the wrist and ankle glide against each other, giving limited but versatile movement.
Correct answer: between the carpal bones of the wrist- A. weakening of the muscles
- B. degeneration of the nerves
- C. inflammation of tendons only
- D. inflammation, pain and stiffness of the joints
Explanation: Whatever the cause, arthritis means an inflamed joint that is painful and stiff.
Correct answer: inflammation, pain and stiffness of the joints- A. Increasing age
- B. A viral infection
- C. Low blood pressure
- D. Excess vitamin D
Explanation: Years of use thin the cartilage and stiffen the joints, so osteoarthritis is commonest after middle age, with obesity and joint injury…
Correct answer: Increasing age- A. cures the disease completely
- B. keeps the joints mobile and strengthens the muscles around them
- C. regrows the worn away cartilage
- D. dissolves calcium out of the bones
Explanation: Movement nourishes cartilage, prevents stiffness and builds supporting muscle, which unloads the joint.
Correct answer: keeps the joints mobile and strengthens the muscles around them- A. eat more organ meats
- B. avoid drinking water
- C. limit purine rich foods and alcohol
- D. stop all physical activity
Explanation: Purines from red meat and organ meats break down to uric acid, the substance that crystallises in the joints during gout, and alcohol…
Correct answer: limit purine rich foods and alcohol- A. a graft of tendon
- B. a long course of antibiotics
- C. physiotherapy alone
- D. an artificial prosthesis of metal and plastic
Explanation: Joint replacement, most often of the hip or knee, fits metal and plastic surfaces where cartilage has vanished, relieving pain and…
Correct answer: an artificial prosthesis of metal and plastic- A. Only collagen
- B. Only calcium phosphate
- C. Collagen and calcium phosphate
- D. Cartilage only
Explanation: Bone contains organic collagen (flexibility) and inorganic calcium phosphate/hydroxyapatite (hardness).
Correct answer: Collagen and calcium phosphate35. Osteoblasts are
- A. Bone-destroying cells
- B. Bone-forming cells
- C. Mature bone cells
- D. Fat cells in bone
Explanation: Osteoblasts are bone-forming cells that secrete collagen and matrix, later becoming osteocytes.
Correct answer: Bone-forming cells- A. Liver
- B. Skin
- C. Intestine
- D. Brain
Explanation: The skin is generally regarded as the heaviest organ of the human body, with its mass including the epidermis, dermis and associated…
Correct answer: Skin- A. 12
- B. 14
- C. 16
- D. 18
Explanation: Humans have 12 pairs of ribs, and the first seven pairs attach directly to the sternum; these are called true ribs.
Correct answer: 14- A. Chondrology
- B. Osteology
- C. Mycology
- D. Histology
Explanation: Osteology is the branch of anatomy concerned with bones and the skeletal system.
Correct answer: Osteology- A. Leg
- B. Ear
- C. Hand
- D. Nose
Explanation: The tibia is the larger medial bone of the lower leg, extending from the knee to the ankle and bearing much of the body's weight.
Correct answer: Leg- A. 212
- B. 206
- C. 300
- D. None of these
Explanation: A human baby has about 300 bones because many skeletal elements are still separate.
Correct answer: 300