Question

(a) what is blood clotting and why is it known to be useful mechanism ?
(b) what is meant by heart beat and what is usual heart beat at rest?

Answer 1

(a)the process by which a protective layer on the wound is known as blood clotting. it is a useful mechanism coz it is useful to heal the wound n the flow of blood stops.

Answer 2

(a) Blood clotting refer to that the red colour solid sunstance formed a layer after occuring wound. The red colour solid substance is known as bloodclot. It is also known as useful mechanism because after occuring of wound, if blood did not clot the blood flow out of our body and cause many diseases related to blood. So it is useful mechanism.
(b) The contraction and relaxation of tricuspid valve and bicuspid valve is known as heart beat.
heart beat=puse rate.
usual heart neat at rest for the age of adults is
72.