Wastewater Story — Science STD 7 — Question

Name the instrument which is used to measure the speed of wind.

What happens if an animal dies in the forest?

Veins have valves which allow blood to flow only in one direction. Arteries do not have valves. Yet the blood flows in one direction only. Can you explain why?

Give examples of plants that reproduce by means of spores.

Paheli remembered that she saw a pipal sapling on the sidewall in her school. Can you help her to understand how this would have happened?

In a mercury thermometer, the level of mercury rises when its bulb comes in contact with a hot object. What is the reason for this rise in the level of mercury?

Name some animals living in rainforest.

The process of fertilisation in plants occurs in which part?

Describe briefly about the direction of the convection current during ventilation.

How many types of elements are there?