A diagrammatic sketch of an actin filament is shown aboye. Answer the following questions.
(a) Name the parts labelled A, B and C.
(b) What is the significance of A during resting stage?
(c) Name the monomers of C.

A diagrammatic sketch of a myosin filament is given above. Answer the following questions.
(a) Identify the following in the diagram of myosin filament.
(i) ATP-binding sites
(ii) Actin-binding sites
(b) Name the monomers of myosin.
(c) Expand
(i) HMM and
(ii) LMM.

Radha was running on a treadmill at a great speed for 15 minutes continuously. She stopped the treadmill abruptly and came out. For the next few minutes, she was breathing heavily/fast. Answer the following questions.
(a) What happened to her muscles, when she strenuously exercised?
(b) Why did her breathing rate change?

A diagram of human rib cage is given above, Observe the diagram and answer the following questions.
(a) What are true ribs? How many are true ribs in the rib cage?
(b) What are vertebrochondral ribs?
(c) Why are the ribs described as bicephalic?

The diagram of a pectoral girdle of a human is shown below. Observe the diagram. fill in the blanks in the description ofthe structure of a pectoral girdle of humans.

Each pectoral girdle is formed of two bones, ______(A) and ________(B) shown in the diagram. The bone B has an elevated ridge, called __________(C), which projects as a flat expanded process, called _________(D), where the A articulates. Below D is a depression called ________(E), where the ________(F) articulates.

A diagram of the bones of pelvic girdle and hind limb is shown above. Observe the diagram and answer the questions given below
(a) Identify the components of a coxal bone of the pelvic bone.
(b) Name the cavity in the pelvic girdle into which the head of femur fits. What Epe of a joint is it?
(c) Name the type of tissue that makes up pubic symphysis.