Which type of joint is involved when you bend your knees and ankles?
Explanation
Option (ii) is correct because the text explicitly states that a hinge joint is present in the knee. A hinge joint bends and straightens in one direction only, similar to a door hinge, which matches the action of bending knees and ankles. Ball and socket joints allow circular and sideways movements (like the shoulder), while pivot joints allow side-to-side movement (like the neck).
Solution Steps
Step 1: Identify the movement described in the question, which is bending the knees and ankles.
Step 2: Review the types of joints mentioned in the text. Ball and socket joints allow movement in multiple directions, pivot joints allow side-to-side movement, and hinge joints bend and straighten in one direction only.
Step 3: Match the joint to the body part. The text specifically notes that a hinge joint is present in the knee, which functions like a door hinge. Therefore, the correct option is (ii).