Answer: Spinal cord and nerve roots.
- A Heart, cushioning it from external impact
- B Spinal cord and nerve roots
- C Lungs, by forming a rigid bony cage around them
- D Brain, by enclosing it within the cranial cavity
Correct answer: B. Spinal cord and nerve roots
Explanation: The vertebral column (spine) encloses and protects the spinal cord within the vertebral canal. It also supports the skull, provides attachment for muscles and ribs, and allows flexible movement of the trunk.
A sarcomere (Z line to Z line): during contraction the I band and H zone shorten as thin filaments slide over thick, while the A band stays the same length. Image: SlothMcCarty, CC BY-SA 3.0, via Wikimedia Commons.
Concept context
Types of movement, muscle contraction, skeletal system, joints, and disorders. Important for Class 11 and NEET.