NEETZoologyLocomotion and Movement
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The joint between the carpal and metacarpal of the human thumb is a saddle joint. Reason (R): It is a type of cartilaginous joint that permits limited movement. In the light of the above statements, choose the most appropriate answer from the options given below:
Options
- A(A) is true but (R) is false.
- BBoth (A) and (R) are true and (R) is the correct explanation of (A).
- CBoth (A) and (R) are true but (R) is not the correct explanation of (A).
- D(A) is false but (R) is true.
Correct answer
A. (A) is true but (R) is false.
Step-by-step solution
Assertion (A) is true because the joint between the carpal and metacarpal of the human thumb is indeed a saddle joint. Reason (R) is false because a saddle joint is a type of synovial joint, not a cartilaginous joint. Synovial joints are characterised by the presence of a fluid-filled synovial cavity between the articulating surfaces of the two bones, which allows considerable movement. Cartilaginous joints, on the other hand, involve bones joined together by cartilage and permit only limited movement (e.g., joints