Electric Current and its Effects — Science STD 7 — Question

While playing in a park, a child was stung by a wasp. Some elders suggested applying paste of baking soda and others lemon juice as remedy. Which remedy do you think is appropriate and why?

Plants are considered an essential part of earth as they keep a check on lot of process occurring all over. What would happen if all the green plants are wiped from earth?

After we work hard or perform physical activity, we feel hungry. Explain why?

Why do farmers grow many fruits and vegetable crops inside large green houses?
What are the advantages to the farmers?

Plants are known as the producers of a food chain. Give reason.

Which type of motion is more common in daily life—uniform or non-uniform? Provide three examples from your experience to support your answer.

Define reproduction. Why is it important?

Paheli noticed water being pulled up by a motor pump to an overhead tank of a five storeyed building. She wondered how water moves up to great heights in the tall trees standing next to the building. Can you tell why?

Three statements are provided here which define the terms, i.e. sludge, sewage and wastewater. Pick out the correct definition for each of these terms.
(i) The settled solids that are removed in wastewater treatment with a scraper.
(ii) Water from kitchen used for washing dishes.
(iii) Wastewater released from homes, industries, hospitals and other public buildings.