Explain the difference between the thermoplastic and thermosetting plastics.

Describe with the help of a diagram an instrument which can be used to detect a charged body.

Sketch larynx and explain its function in your own words.

Arrange the following boxes in proper order to make a flow chart of sugarcane crop production.

Make a labelled diagram of a candle flame.

What is metamorphosis? Give examples.

The following Table shows the total power shortage in India from 1991– 1997. Show the data in the form of a graph. Plot shortage percentage for the years on the Y-axis and the year on the X-axis.

Make sketches of animal and plant cells. State three differences between them.

What is a constellation? Name any two constellations.

Describe the construction of a kaleidoscope.

Complete the crossword with the help of clues given below:
Across
1. This is necessary for photosynthesis.
3. Term for component present in the cytoplasm.
6. The living substance in the cell.
8. Units of inheritance present on the chromosomes.

Down
1. Green plastids.
2. Formed by collection of tissues.
4. It separates the contents of the cell from the surrounding medium.
5. Empty structure in the cytoplasm.
7. A group of cells.

Explain why sportsmen use shoes with spikes.

Differentiate between internal fertilization and external fertilization.

What is the term used for secretions of endocrine glands responsible for changes taking place in the body?

A child staying in a coastal region tests the drinking water and also the seawater with his tester. He finds that the compass needle deflects more in the case of seawater. Can you explain the reason?

List sources of noise pollution in your surroundings.

Write notes on—
(a) Adam’s apple.
(b) Secondary sexual characters.
(c) Sex determination in the unborn baby.

Which of the following is not a greenhouse gas?
(a) Carbon dioxide
(b) Sulphur dioxide                                                                                                                                                                                                                                  (c) Methane
(d Nitrogen

Does pure water conduct electricity? If not, what can we do to make it conducting?

In the following Table some substances are given in Column I. In Column II some uses are given. Match the items in column I with those in Column II.

What is irrigation? Describe two methods of irrigation which conserve water.