Water plants provide ....... to water animals
$O_2$and food
Water and $CO_2$
Food and water
Shelter and shade
Which one of the following types of organisms occupy more than one trophic level in a pond ecosystem?
Which of the following food chain may not be directly dependent upon solar energy
In a lake, phytoplankton grow abundant in
In a biotic community, primary consumers are
The trophic level of lion in a forest ecosystem is