Sound — Science STD 8 — Question

Make a sketch of the human muscle cell. What are the functions do muscles cell perform?

Define asexual reproduction. Name two methods of asexual reproduction in animals. Name two animals which reproduce by these asexual reproduction methods.

State two uses of melamine.

What depletes the ozone layer in the atmosphere? What are the harmful effects of the depletion of ozone layer on us?

Give reason for the following:
Paper by itself catches fire easily whereas a piece of paper wrapped around an aluminium pipe does not.

State five uses of artificial satellites.

In case of a fire, before the firemen use the water hoses to throw water to douse fire, they shut off the electricity supply for the area. Explain why this is done.

What is meant by the phases of the Moon? What causes the phases of the Moon?

How does deforestation cause soil erosion?

When a lot of dry powder of a substance X is released over a fire, the fire gets extinguished.

1. Name the substance X.
2. How does this substance extinguish the fire?
3. Name another susbtance which behaves like X.