It is known that red muscle fibres in animals can work for longer periods of time continuously. How is this possible?

Flexion of the thigh,knee,and their rotation is facilitated by:

Define the following terms:
$(1)$ Sarcomere
$(2)$ Acromion process

The contraction of muscle of shortest duration is seen in

Given below are two statements $:-$
Statement-$I$ :- Each organised skeletal muscle in human body is made of a number of fascicles,held together by a common connective tissue layer called fascia.
Statement-$II$ :- The portion of the myofibril between two successive '$Z$' lines is considered as the functional unit of muscle contraction,known as a sarcomere.
In the light of the above statements,choose the correct answer from the options given below $:-$

Which of the following is not a part of the thin filament?