When we touch a hot plate unknowingly, then this heat is sensed by a receptor P present in our fingers. The receptor triggers an impulse in neuron Q which transmits the message to an organ R which is a part of the central nervous system. Here the impulse is passed on to a neuron S which in turn passes it to a yet another neuron T. The neuron T passes the impulse to a tissue U in our arm. The tissue U then contracts and pulls our hand away from the hot plate.​ ​
(a) What is the name of (i) receptor P (ii) neuron Q, and (iii) organ R?​

Q. When we touch a hot plate unknowingly, then this heat is sensed by a receptor P present in our fingers. The receptor triggers an impulse in neuron Q which transmits the message to an organ R which is a part of the central nervous system. Here the impulse is passed on to a neuron S which in turn passes it to a yet another neuron T. The neuron T passes the impulse to a tissue U in our arm. The tissue U then contracts and pulls our hand away from the hot plate.​ ​
(b) What is (i) neuron S, and (ii) neuron T?​

Q. When we touch a hot plate unknowingly, then this heat is sensed by a receptor P present in our fingers. The receptor triggers an impulse in neuron Q which transmits the message to an organ R which is a part of the central nervous system. Here the impulse is passed on to a neuron S which in turn passes it to a yet another neuron T. The neuron T passes the impulse to a tissue U in our arm. The tissue U then contracts and pulls our hand away from the hot plate.​ ​
(d) What name is given to the phenomenon in which hand is pulled away quickly from the hot plate?​ ​

Q. Fill in the following blanks with suitable words :
(a) The two examples of effectors are .........and ...........
(b) Our.............system allows us to react to our surroundings. Information from receptors passes along...........neurons to our brain. Our brain sends impulses along..........neurons to our muscles.
(c) A neuron which carries an impulse to the brain is called a ........... neuron.
(d) The neuron which carries a message for action to a muscle or gland is known as a......... neuron.

Q. Which structure of nervous system permits a neuron to pass impulse to another neuron?

Q. Assertion :After hearing a sound, nerve impulse passes from neurons to the brain. Reason: The neuron which pass nerve impulse from organs to the brain is called afferent neuron.