Acid rain is due to increase in atmospheric concentration of :

• Ozone

• CO₂ and CO

• SO₃ and CO

• SO₂ and nitrogen oxide

Which of the following factor is biotic

• Photoperiod

• CO₂ content to the soil

• Texture and porosity of soil

• Rainfall

The pyramid of energy-in a forest ecosystem is

• always upright

• always inverted

• both (a) and (b)

• none of the above

Identify which one of the following is an example, of incomplete ecosystem?

• Grassland

• Cave

• River

• Wetland

Which of the following is an example of man-made ecosystem

• Herbarium

• Aquarium

• Tissue culture

• Forest

Identify the correct type of food chain

Dead animal > Blow fly maggots > Common frog > Snake

• Grazing food chain

• Detrital food chain

• Decomposer food chain

• Predator food chain

197.

Acid rain is caused by

• NO₂

• SO₂ and NO₂

• SO₃

• CO₂

When the two ecosystems overlap each other, the area is called

• habitat

• niche

• ecotone

• ecotype

Pyramid of energy in ecosystems is

• always upright

• always inverted

• mostly upright

• mostly inverted

Trophic levels in ecosystem is formed by

• only bacteria

• only plants

• only herbivores

• organisms linked in food chain