Micro-Organisms: Friends and Foe — Science STD 8 — Question

On what factor does the loudness of a sound depend?

State whether the following statements are True or False:
Egg laid after fertilization is made up of a single cell.

During electrolysis of water what is formed at anode?

Give two natural resources. Why these are called natural resources ?

Fill in the following blanks with suitable words: The two common methods of asexual reproduction in animals are ______________ and ______________.

Name the disease caused by the insufficient production of insulin hormone by pancreas.

Pahell and Boojho realised that sudden increase in height and hairy line above the lips in boys were signs of adolescence. They wanted to know about other changes at puberty.

Name one metal which does not react with dilute hydrochloric acid.

Name the quantity whose unit is 'hertz'.

Is it possible to extract petroleum from under the sea ?