Health: The Ultimate Treasure — Science STD 8 — Question

Yeast is used for commercial use. Write one commercial use of yeast.

What happens when the two forces act in the opposite direction on an object?

State an important characteristic of muscles cells.

Rohit took with him some nylon ropes, when he was going for rock climbing. Can you tell why he selected nylon ropes instead of ropes made of cotton or jute?

What type of plants can fix nitrogen gas of the air into compounds of nitrogen?

Name a device which glows even when a weak electric current passes through it.

Which gas in the atmosphere is used by the trees and plants in photosynthesis?

A doctor prescribed a tablet to a patient suffering from iron deficiency. The tablet does not look like iron. Explain.

Fill in the blanks with the help of words given in bracket after each sentence. Many ________ are responsible for causing ________ pollution. Petroleum ________ are a major source of ________ pollutants like ________ and ________. (sulphur dioxide, refineries, industries, nitrogen dioxide, gaseous, liquid, people, air).

State whether the following statements are True or False: An embryo is made up of a single cell.