$A$ motor unit is a

Which of the following movements in the mammalian skeleton represents the leverage of the third order,where the force is applied at a point between the fulcrum and the point of resistance?

Which of the following statements is true with reference to the structure of a muscle fibre?

Select the correct option for the following statements:
$(i)$ The most important respiratory organ in frogs is the skin / lungs.
(ii) Skeletal muscle / Cardiac muscle exhibits rhythmic contraction.

The functional unit of contraction is a

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 $:-$