(a) Plants lack a specialised respiratory system. How do they carry out respiratory process? Explain.
(b) The plant roots being underground respire by using which mechanism?

Paheli participated in a 400 m race competition held at her school and won the race. When she came home she had mixed feelings of joy and pain as she had cramps in her leg muscles. After a massage, she was relieved of the pain. Answer the following questions related to the situation.
(a) What can be the possible reasons for the pain in her legs?
(b) Why did she fell comfortable after a massage?

It is not wise to sleep under a tree during night. Why?

Observe the figures carefully and answer the following questions.

(a) Which process is being tested in the activity?
(b) What is the result of the activity? Give reasons.

(a) Respiratory process occurs in two phases, what are those two major steps of respiration? Describe each one.
(b) Define the term breathing rate.

Observe the given figures as A and Band answer the following questions

(a) Among both figures identity which A or B indicates the process of inhalation and which shows the process of exhalation?
(b) In the figure label the arrows and indicate the direction of
(i) movement of air (ii) movement of diaphragm (iii) movement of ribs

List some animals around you. Now group them as follows:
(a) Animals that can breathe only through skin.
(b) The animal that can breathe through skin as well as through lungs.
(c) The animal that can breathe through lungs.
(d) Animals that can breathe through gills.
(e) Animals that can breathe through spiracle and tracheae?

Palak wants to be a great cyclist. She cycles daily for about 2 hours followed by some exercises. Today, she thought she will cycle for longer and managed it for 4Y2 hours. Now she is feeling cramped up and her breathing is disturbed. Her mother took her to hospital where the doctor examined and told her not to push herself more than necessary. Palak understood and promised herself to move show and steadily.
(a) Why did Palak had cramps in her legs?
(b) Is breathing rate also affected after doing long hour of exercise. Why?
(c) When there is not enough oxygen supply, what happens to body and process of respiration? What values you learn from this?

A person put some warm water in an aquarium having fish during winter season. He thought that fish will be more comfortable in luke warm water than cold water. But he observed that fishes in the aquarium died. Why the fishes died in warm water?

A group of people were smoking cigarettes in a restaurant. The atmosphere was full of smoke. An old man sitting next to the group asked them to stop smoking while sitting in the premise or move out. They agreed to do so and promised not to repeat then mistake.
Answer the following questions.
(a) Write any three hazards of smoking.
(b) Can smoking also affect the person who does not smoke?
(c) Do you support the group's decision to not smoke in public or indiviually. What values do we understand from here.