MCQ on Skeletal System

🟢 Easy Level (1–20)

1. How many bones are in the adult human skeleton?
   A) 200
   B) 206 ✅
   C) 210
   D) 201
   Explanation: An adult human has 206 bones.
2. Which is the longest bone in the human body?
   A) Tibia
   B) Humerus
   C) Femur ✅
   D) Radius
   Explanation: The femur (thigh bone) is the longest and strongest bone.
3. What is the main function of the skeletal system?
   A) Digestion
   B) Blood purification
   C) Structural support ✅
   D) Hormone secretion
   Explanation: The skeleton provides structure and support for the body.
4. Which bone protects the brain?
   A) Sternum
   B) Skull ✅
   C) Rib cage
   D) Pelvis
   Explanation: The skull encases and protects the brain.
5. The bones of the spine are called:
   A) Ribs
   B) Vertebrae ✅
   C) Carpals
   D) Tarsals
   Explanation: The vertebral column (spine) is made up of vertebrae.
6. How many ribs does a typical human have?
   A) 10
   B) 12 pairs ✅
   C) 14
   D) 24 individual
   Explanation: 12 pairs = 24 ribs.
7. Which bone is commonly known as the collarbone?
   A) Scapula
   B) Clavicle ✅
   C) Sternum
   D) Humerus
   Explanation: The clavicle connects the shoulder to the sternum.
8. The kneecap is also known as the:
   A) Tibia
   B) Fibula
   C) Patella ✅
   D) Femur
   Explanation: The patella is the small bone that covers the knee joint.
9. What type of joint is the shoulder joint?
   A) Hinge
   B) Ball and socket ✅
   C) Pivot
   D) Gliding
   Explanation: Ball-and-socket joints allow movement in all directions.
10. Which bone is not part of the axial skeleton?
    A) Skull
    B) Vertebrae
    C) Pelvis ✅
    D) Ribs
    Explanation: The pelvis is part of the appendicular skeleton.
11. Which mineral is most abundant in bones?
    A) Iron
    B) Phosphorus
    C) Calcium ✅
    D) Magnesium
    Explanation: Calcium phosphate gives bones strength.
12. Where is the humerus located?
    A) Leg
    B) Arm ✅
    C) Foot
    D) Spine
    Explanation: The humerus is the upper arm bone.
13. Which type of bone forms the wrist?
    A) Tarsals
    B) Carpals ✅
    C) Metacarpals
    D) Phalanges
    Explanation: The wrist consists of carpal bones.
14. The hip bone is scientifically called the:
    A) Femur
    B) Tibia
    C) Pelvis ✅
    D) Coccyx
    Explanation: The pelvis supports the lower limbs.
15. Which part of the bone produces blood cells?
    A) Compact bone
    B) Spongy bone
    C) Bone marrow ✅
    D) Cartilage
    Explanation: Bone marrow, especially red marrow, is responsible for hematopoiesis.
16. The lower jawbone is known as:
    A) Maxilla
    B) Mandible ✅
    C) Zygomatic
    D) Frontal
    Explanation: The mandible is the movable lower jaw.
17. Which bones form the fingers?
    A) Metacarpals
    B) Carpals
    C) Phalanges ✅
    D) Tarsals
    Explanation: Phalanges make up fingers and toes.
18. What type of joint is found in the elbow?
    A) Ball and socket
    B) Hinge ✅
    C) Pivot
    D) Saddle
    Explanation: Hinge joints allow bending and straightening.
19. Which bone is located in the forearm?
    A) Femur
    B) Tibia
    C) Radius ✅
    D) Fibula
    Explanation: The radius is one of the two bones in the forearm.
20. The vertebral column consists of how many vertebrae?
    A) 30
    B) 33 ✅
    C) 28
    D) 26
    Explanation: 33 vertebrae in total: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused), 4 coccygeal (fused).

🟡 Moderate Level (21–40)

21. Which part of the skeleton includes limbs and girdles?
    A) Axial skeleton
    B) Appendicular skeleton ✅
    C) Cranial skeleton
    D) Thoracic skeleton
    Explanation: Appendicular skeleton includes arms, legs, and girdles.
22. Which bone connects the arm to the trunk?
    A) Radius
    B) Ulna
    C) Clavicle ✅
    D) Femur
    Explanation: Clavicle acts as a strut between the scapula and sternum.
23. The scapula is commonly called the:
    A) Collarbone
    B) Shoulder blade ✅
    C) Tailbone
    D) Breastbone
    Explanation: Scapula is the flat, triangular bone at the back of the shoulder.
24. Which bone forms the forehead?
    A) Parietal
    B) Temporal
    C) Frontal ✅
    D) Occipital
    Explanation: The frontal bone is located at the front of the skull.
25. How many bones are in the human hand (including wrist)?
    A) 27 ✅
    B) 30
    C) 25
    D) 29
    Explanation: 8 carpals, 5 metacarpals, and 14 phalanges = 27 bones.
26. The region where two or more bones meet is called a:
    A) Muscle
    B) Tendon
    C) Joint ✅
    D) Ligament
    Explanation: Joints allow movement and flexibility.
27. Which bone forms the base of the skull?
    A) Parietal
    B) Temporal
    C) Occipital ✅
    D) Ethmoid
    Explanation: The occipital bone forms the posterior base of the skull.
28. Which connective tissue joins muscle to bone?
    A) Ligament
    B) Tendon ✅
    C) Cartilage
    D) Fascia
    Explanation: Tendons connect muscles to bones.
29. Osteocytes are found in which tissue?
    A) Muscle
    B) Nerve
    C) Bone ✅
    D) Cartilage
    Explanation: Osteocytes are mature bone cells found in bone matrix.
30. The bone that does not articulate with any other bone is the:
    A) Mandible
    B) Hyoid ✅
    C) Atlas
    D) Sacrum
    Explanation: The hyoid bone supports the tongue and is not attached to other bones.
31. Which bones form the ankle joint?
    A) Tibia and Fibula with Talus ✅
    B) Femur and Patella
    C) Ulna and Radius
    D) Tibia and Calcaneus
    Explanation: The ankle joint is formed by tibia, fibula, and talus.
32. Growth in the length of long bones occurs at the:
    A) Diaphysis
    B) Epiphysis
    C) Epiphyseal plate ✅
    D) Periosteum
    Explanation: The epiphyseal plate (growth plate) is responsible for lengthening.
33. The adult pelvis is composed of:
    A) Ilium, ischium, and pubis ✅
    B) Femur, tibia, and fibula
    C) Coxal, sacrum, and coccyx
    D) Hip, spine, and femur
    Explanation: These three bones fuse to form each hip bone.
34. Which bones make up the pectoral girdle?
    A) Clavicle and scapula ✅
    B) Scapula and sternum
    C) Clavicle and humerus
    D) Sternum and ribs
    Explanation: The clavicle and scapula connect the arms to the trunk.
35. Flat bones are typically found in the:
    A) Limbs
    B) Skull ✅
    C) Fingers
    D) Ankles
    Explanation: Flat bones like frontal and parietal protect soft organs.
36. A fracture that breaks the skin is called:
    A) Simple
    B) Compound ✅
    C) Greenstick
    D) Spiral
    Explanation: A compound fracture breaks through the skin, increasing infection risk.
37. Bone cells that break down bone are called:
    A) Osteoblasts
    B) Osteocytes
    C) Osteoclasts ✅
    D) Chondrocytes
    Explanation: Osteoclasts dissolve bone tissue during remodeling.
38. What type of bone is the sternum?
    A) Irregular
    B) Long
    C) Flat ✅
    D) Short
    Explanation: The sternum is a flat bone in the chest.
39. Which bones form the arch of the foot?
    A) Carpals
    B) Metatarsals ✅
    C) Tarsals
    D) Phalanges
    Explanation: Metatarsals form the arch and structure of the foot.
40. What covers the outer surface of bones?
    A) Endosteum
    B) Cartilage
    C) Periosteum ✅
    D) Marrow
    Explanation: The periosteum is a dense connective tissue layer.

🔴 Hard Level (41–50)

41. Which enzyme is secreted by osteoclasts to dissolve bone matrix?
    A) Pepsin
    B) Collagenase ✅
    C) Lipase
    D) Amylase
    Explanation: Osteoclasts secrete collagenase to degrade collagen in bone.
42. Which hormone increases blood calcium by stimulating bone breakdown?
    A) Calcitonin
    B) Estrogen
    C) Parathyroid hormone ✅
    D) Insulin
    Explanation: PTH stimulates osteoclast activity to release calcium.
43. The foramen magnum is found in which bone?
    A) Frontal
    B) Temporal
    C) Occipital ✅
    D) Parietal
    Explanation: The foramen magnum is the large opening in the occipital bone.
44. The axis is the:
    A) First cervical vertebra
    B) Second cervical vertebra ✅
    C) Third cervical vertebra
    D) Last thoracic vertebra
    Explanation: The axis (C2) allows head rotation with the atlas.
45. Intramembranous ossification forms which bones?
    A) Long bones
    B) Vertebrae
    C) Skull bones ✅
    D) Pelvis
    Explanation: Flat bones like the skull develop directly from mesenchyme.
46. The bone matrix is primarily made of:
    A) Chitin
    B) Collagen and hydroxyapatite ✅
    C) Keratin
    D) Elastin
    Explanation: The matrix contains collagen and mineral salts like calcium phosphate.
47. Which condition involves softening of bones in adults?
    A) Rickets
    B) Osteomalacia ✅
    C) Osteomyelitis
    D) Arthritis
    Explanation: Osteomalacia is caused by vitamin D deficiency in adults.
48. Which part of the bone contains yellow marrow?
    A) Epiphysis
    B) Diaphysis ✅
    C) Metaphysis
    D) Periosteum
    Explanation: The medullary cavity in the diaphysis stores yellow (fatty) marrow.
49. Which type of joint is immovable?
    A) Hinge
    B) Ball and socket
    C) Fibrous ✅
    D) Synovial
    Explanation: Fibrous joints like sutures in the skull do not move.
50. A sesamoid bone is embedded in a:
    A) Ligament
    B) Tendon ✅
    C) Muscle
    D) Cartilage
    Explanation: Sesamoid bones (like the patella) form within tendons to reduce stress.