Give suitable explanations for the following:
Why do you shiver and why do your teeth chatter when it is very cold in winter?

Q. SHORT ANSWER TYPE
Why do you shiver and why do your teeth chatter when it is very cold in winter ?

Q. Give suitable explanations for the following:
(a) Breathing through the nose is said to be healthier than through the mouth.
(b) Why does gaseous exchange continue in the lungs even during expiration?
(c) Why does a person feel breathlessness at higher altitudes?
(d) Why do you shiver and why do your teeth chatter when it is very cold in winter?

Q. Why do we feel cold during winter?

Q. Narrate an incident from your own experience when you expected to do very well, but for some reason were unable to do so. Explain what happened and why it happened. What lesson did you learn from it?