Word game : Use the clues to work out the words.

Across
3. Protruding voice box in boys
4. Glands without ducts
7. Endocrine gland attached to brain
8. Secretion of endocrine glands
9. Pancreatic hormone
10. Female hormone

Down
1. Male hormone
2. Secretes thyroxine
3. Another term for teenage
5. Hormone reaches here through blood stream
6. Voice box
7. Term for changes at adolescence

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.

What is metamorphosis? Give examples.

Make a labelled diagram of a candle flame.

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

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.

Make a sketch of the human nerve cell. What function do nerve cells perform?

Make a labelled diagram of a candle flame.

Which zone of a flame does a goldsmith use for melting gold and silver and why?

The process that you saw in Activity 14.7 is used for purification of copper. A thin plate of pure copper and a thick rod of impure copper are used as electrodes. Copper from impure rod is sought to be transfered to the thin copper plate. Which electrode should be attached to the positive terminal of battery and why?

Iqbal has to push a lighter box and Seema has to push a similar heavier box on the same floor. Who will have to apply a larger force and why?

It is difficult to burn a heap of green leaves but dry leaves catch fire easily. Explain.

Suppose you are in a dark room. Can you see objects in the room? Can you see objects outside the room. Explain.

An inflated balloon was pressed against a wall after it has been rubbed with a piece of synthetic cloth. It was found that the balloon sticks to the wall. What force might be responsible for the attraction between the balloon and the wall?

Suggest three measures to protect ourselves from lightning.

Which of the following is NOT a planet of the sun?
(a) Sirius
(b) Mercury
(c) Saturn
(d) Earth

Draw sketches to show the relative positions of prominent stars in
(a) Ursa Major and (b) Orion