Unit 3A: Musculo-Skeletal System — Online MCQ Test
ZOOLOGY · CLASS 12 INTERMEDIATE 2 YEAR · Telangana State Board
Practice Unit 3A: Musculo-Skeletal System with a free chapter-wise online MCQ test.
This chapter covers: Focusing on human movement this chapter details skeletal system architecture bone joints muscle contraction mechanics sliding filament theory and musculoskeletal disorders..
AI-generated questions from basic to board-exam level, with instant results and explanations.
Unit 3A: Musculo-Skeletal System — Important Questions & Answers
Which of the following is the main mineral component of bone?
- A. Calcium phosphate
- B. Sodium chloride
- C. Potassium iodide
- D. Magnesium sulfate
Answer: A. Calcium phosphate
Bones are hardened mainly by calcium phosphate deposited in the bone matrix. This gives bone its strength and rigidity.
Bones are hardened mainly by calcium phosphate deposited in the bone matrix. This gives bone its strength and rigidity.
The joint present between the atlas and axis vertebrae is a/an:
- A. Hinge joint
- B. Pivot joint
- C. Ball and socket joint
- D. Gliding joint
Answer: B. Pivot joint
The atlanto-axial joint is a pivot joint that allows rotation of the head from side to side.
The atlanto-axial joint is a pivot joint that allows rotation of the head from side to side.
The sliding filament theory explains muscle contraction by the interaction between:
- A. Actin and myosin filaments
- B. Calcium and phosphorus
- C. Ligaments and tendons
- D. Cartilage and bone
Answer: A. Actin and myosin filaments
During contraction, actin filaments slide over myosin filaments, shortening the sarcomere.
During contraction, actin filaments slide over myosin filaments, shortening the sarcomere.
In the sliding filament theory, the length of which structure remains constant during contraction?
- A. A band
- B. I band
- C. H zone
- D. Sarcomere
Answer: A. A band
The A band remains constant because the thick myosin filaments do not change in length during contraction.
The A band remains constant because the thick myosin filaments do not change in length during contraction.
Which one of the following is the most appropriate explanation for osteoporosis?
- A. Excess accumulation of calcium in bones leading to stiffness
- B. Loss of bone mass and increased fragility of bones
- C. Inflammation of skeletal muscles causing cramps
- D. Fusion of joints leading to immobility
Answer: B. Loss of bone mass and increased fragility of bones
Osteoporosis is characterized by reduced bone density and increased risk of fractures due to weakened bones.
Osteoporosis is characterized by reduced bone density and increased risk of fractures due to weakened bones.