Fibre to Fabric — Science STD 7 — Question

When a candle burns, both physical and chemical changes take place. Identify these changes. Give another example of a familiar process in which both the chemical and physical changes take place.

If one component of the forest is removed, what would be its affect on the ecosystem?

Food moves in the opposite direction during vomiting. How?

What is the effect of ant bite? Explain its cure.

Name two alternative arrangements for sewage disposal where there is no sewerage system.

What are the benefits of conducting experiments and asking questions in science? How does this lead to deeper understanding and further exploration?

Name two units used to measure time.

Ruminants such as cows and buffaloes swallow their food hurriedly and store it in a part of the stomach called rumen. The cellulose of the food is digested here by the action of certain bacteria, which are not present in humans. Later their partially digested food is returned to the buccal cavity of the animals in small lumps and animals chew it to complete the process of digestion. This process is called rumination.

Is science limited only to laboratories?

Explain why there is a need of variety of animals and plants in a forests.