NEETZoologyLocomotion and Movement
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Skeletal muscle fibres show a characteristic striated appearance. Reason (R): The light bands contain myosin and are called I-bands, whereas the dark bands contain actin and are called A-bands. 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 skeletal muscle fibres have a characteristic striated (striped) appearance under the microscope. Reason (R) is false because the light bands contain actin and are called I-bands (Isotropic bands), whereas the dark bands contain myosin and are called A-bands (Anisotropic bands). The statement incorrectly swaps the protein composition of the bands. Answer: (A) is true but (R) is false.