How Nature Works in Harmony — Science STD 8 — Question

State whether the following statements are True or False: A new human individual develops from a cell called gametes.

Paheli has heard that some of the endemic species may vanish. Is it true ?

Give one example where force changes the direction of a moving object.

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 the function of male sex hormone ‘testerone’.

Which produces sound of a higher pitch: a drum or a whistle?

Fill in the blanks. During the processing of coal to get coke, coal tar and ________ are also obtained.

Why is the use of diesel and petrol as fuels in automobiles being replaced by Compressed Natural Gas (CNG) in big cities ?

Name two food materials which are preserved by sun-drying method in our homes.

Name the largest planet of the solar system.