NUST NET Medical / Biological Sciences Biology Support & Movement — Set 2

NUST NET Medical / Biological Sciences Biology Support & Movement — Set 2

1. Question 1

   Q1. During muscle contraction, what is the role of troponin?

   • A) Blocks actin-myosin binding site
   • B) Binds to calcium ions
   • C) Provides ATP for contraction
   • D) Forms cross-bridges with actin

   Answer: Blocks actin-myosin binding site

   Explanation: Troponin blocks actin-myosin binding site in relaxed muscle; option B is related but incorrect as it's tropomyosin that moves.

2. Question 2

   Q2. What is the primary function of the skeletal system?

   • A) Support and protection
   • B) Production of hormones
   • C) Regulation of body temperature
   • D) Circulation of blood

   Answer: Support and protection

   Explanation: Skeletal system provides structural support and protects internal organs; other options are not its primary functions.

3. Question 3

   Q3. Which type of cartilage is found in the intervertebral discs?

   • A) Hyaline cartilage
   • B) Elastic cartilage
   • C) Fibrocartilage
   • D) Adipose tissue

   Answer: Fibrocartilage

   Explanation: Fibrocartilage is found in intervertebral discs due to its high tensile strength; hyaline and elastic cartilage have different properties.

4. Question 4

   Q4. A person with a fractured femur is unable to bear weight. Which bone structure is most likely damaged?

   • A) Compact bone
   • B) Spongy bone
   • C) Periosteum
   • D) Endosteum

   Answer: Compact bone

   Explanation: Compact bone provides structural support; damage to it can lead to inability to bear weight.

5. Question 5

   Q5. What is the term for the movement of a limb away from the midline of the body?

   • A) Abduction
   • B) Adduction
   • C) Flexion
   • D) Extension

   Answer: Abduction

   Explanation: Abduction is movement away from the body's midline; adduction is the opposite movement.

6. Question 6

   Q6. Which of the following joints is an example of a synarthrodial joint?

   • A) Gomphosis
   • B) Hinge joint
   • C) Ball-and-socket joint
   • D) Pivot joint

   Answer: Gomphosis

   Explanation: Gomphosis is a synarthrodial joint where a tooth is anchored; other options are types of synovial joints.

7. Question 7

   Q7. During strenuous exercise, which energy source is primarily used by muscles?

   • A) Glucose
   • B) Fatty acids
   • C) Amino acids
   • D) Lactic acid

   Answer: Glucose

   Explanation: Glucose is the primary energy source during strenuous exercise; it's broken down anaerobically to produce ATP quickly.

8. Question 8

   Q8. What is the function of the sarcolemma in muscle fibers?

   • A) To conduct nerve impulses
   • B) To store calcium ions
   • C) To surround and protect the muscle fiber
   • D) To synthesize proteins

   Answer: To surround and protect the muscle fiber

   Explanation: Sarcolemma is the plasma membrane surrounding muscle fibers, protecting and enclosing the fiber.

9. Question 9

   Q9. Which type of muscle fiber is adapted for endurance activities?

   • A) Slow-twitch oxidative fibers
   • B) Fast-twitch glycolytic fibers
   • C) Fast-twitch oxidative fibers
   • D) Intermediate fibers

   Answer: Slow-twitch oxidative fibers

   Explanation: Slow-twitch oxidative fibers are rich in myoglobin and mitochondria, making them suitable for endurance activities.

10. Question 10

    Q10. What is the role of the Haversian canal in compact bone?

    • A) To provide a site for bone resorption
    • B) To house blood vessels and nerves
    • C) To store bone marrow
    • D) To produce bone cells

    Answer: To house blood vessels and nerves

    Explanation: Haversian canal contains blood vessels and nerves that supply the compact bone.

11. Question 11

    Q11. A 25-year-old man injures his knee, damaging the ACL. Which movement is most affected?

    • A) Flexion
    • B) Extension
    • C) Rotation
    • D) Anterior translation of tibia

    Answer: Anterior translation of tibia

    Explanation: ACL prevents anterior translation of tibia; damage to ACL affects this movement.

12. Question 12

    Q12. What is the primary function of osteoclasts?

    • A) To form bone matrix
    • B) To resorb bone tissue
    • C) To regulate calcium levels
    • D) To produce bone marrow

    Answer: To resorb bone tissue

    Explanation: Osteoclasts are responsible for bone resorption; they break down bone tissue.

13. Question 13

    Q13. During muscle contraction, what happens to the length of the sarcomere?

    • A) It remains the same
    • B) It increases
    • C) It decreases
    • D) It becomes irregular

    Answer: It decreases

    Explanation: Sarcomere shortens during muscle contraction; this is the basis of muscle contraction.

14. Question 14

    Q14. Which ligament connects the femur to the tibia?

    • A) Anterior cruciate ligament
    • B) Posterior cruciate ligament
    • C) Medial collateral ligament
    • D) Patellar ligament

    Answer: Anterior cruciate ligament

    Explanation: ACL connects femur to tibia; it's crucial for knee stability.

15. Question 15

    Q15. What is the function of the menisci in the knee joint?

    • A) To absorb shock and distribute load
    • B) To produce synovial fluid
    • C) To stabilize the joint
    • D) To facilitate movement

    Answer: To absorb shock and distribute load

    Explanation: Menisci absorb shock and distribute load; they also help in reducing friction.

16. Question 16

    Q16. Which bone marking is a site for muscle attachment?

    • A) Foramen
    • B) Fissure
    • C) Tubercle
    • D) Meatus

    Answer: Tubercle

    Explanation: Tubercle is a site for muscle attachment; other options are different types of bone markings.

17. Question 17

    Q17. What is the term for the process of bone formation?

    • A) Ossification
    • B) Resorption
    • C) Remodeling
    • D) Calcification

    Answer: Ossification

    Explanation: Ossification is the process of bone formation; it's a critical aspect of bone development.

18. Question 18

    Q18. Which type of synovial joint allows movement in only one plane?

    • A) Hinge joint
    • B) Ball-and-socket joint
    • C) Pivot joint
    • D) Plane joint

    Answer: Hinge joint

    Explanation: Hinge joint allows movement in one plane; examples include elbow and knee joints.

19. Question 19

    Q19. What is the role of the synovial fluid in joints?

    • A) To lubricate the joint
    • B) To provide structural support
    • C) To produce bone cells
    • D) To regulate body temperature

    Answer: To lubricate the joint

    Explanation: Synovial fluid lubricates the joint; it reduces friction between articulating bones.

20. Question 20

    Q20. A person has a condition where the intervertebral discs are degenerating. Which symptom is most likely?

    • A) Back pain
    • B) Headache
    • C) Muscle weakness
    • D) Numbness in limbs

    Answer: Back pain

    Explanation: Degenerating intervertebral discs can cause back pain due to reduced cushioning and support.