The dominant second trophic level, in a lake ecosystem is
benthos
plankton
zooplankton
phytoplankton
One of the following is not a biodegradable material. This one is:
cotton
animal bones
aluminium foil
wood
Primary or first order consumers are also known as
autotrophs
heterotrophs
herbivores
carnivores
All food chains in a community give rise to a
climax community
food web
biosphere
ecosystem
Sahara Desert was formed over a period of time due to one of the following uncontrolled activities of man:
a) excessive cutting down of forest plants and trees
excessive killing of large herbivores
excessive killing of large carnivores
excessive use of poisonous chemicals called herbicides
What percentage of sun's energy falling on the leaves of green plants is utilised by the plants in the process of photosynthesis and stored as chemical energy of food?
99 per cent
10 per cent
1 per cent
20 per cent
A balanced aquarium is best described as
a biome
an ecosystem
a community
a biosphere
Which of the following cannot be added in a composting pit to prepare compost?
sunflower plants
fruit and vegetable peels
flowers of plastic
red worms
In a food chain, the third trophic level is always occupied by:
decomposers
producers
In an ecosytem, bacteria are considered as
micro-consumers
macro-consumers
primary consumers
secondary consumers
