Savannas are .....

In lower organisms,the formation of thick-walled spores helps them to survive in unfavorable conditions. What is this process called?

Many freshwater animals cannot live for long in sea water and vice-versa mainly because of the

Community is:
$I.$ Group of independent,interacting populations of same species
$II.$ Group of independent and interacting populations of same species in specific area
$III.$ Group of independent interacting populations of different species in a specific area
$IV.$ Group of independent and interacting populations of different species in different area
Select the correct option.

Animals which live at the bottom of the sea are known as:

Choose the incorrect sentence.