Biology M.C.Q (1 Marks)

Global warming is a direct result of the increased imbalance of gases in the atmosphere.

Suspended solids can be removed by sedimentation and decantation. Dissolved solids can be removed by evaporation of water which is an energy intensive process. Removal of colloids needs centrifugation. Removal of bacteria involves use of bactericidal agents.

Styro foam prevents reflection of sound waves instead it absorbs them after their collision.

The greenhouse effect is caused by the greenhouse gases. The gases methane, carbon dioxide, and water vapour trap the solar radiations which need to be reflected back to the atmosphere and increase the temperature of the earth.
The greenhouse is considered as the direct cause of global warming.

Animals living in the forest include herbivores and carnivores. The dung of these animals are decomposed by insects living in the soil.
This contributes to the fertility of the soil by adding organic matter and nutrients, such as nitrogen, that is trapped by bacteria in the soil. This provides nutrients to the seedlings to grow in forests.

With the advent of progressing trade, commerce and industry the means and the usage of transport has also increased. Be any trade or industry, transport is the final step for its execution

Use of insecticides, pesticides and fertilizers in agricultural activities has grown quite a lot hazardous ammonia gases in the atmosphere.

Proper balance of all the abiotic and biotic components is the only way to preserve an ecosystem.

Pesticides when sprinkled on crops and plants also get mixed by water in the field and leads to water pollution.

Explanation: d. Tectona - Temperate forest
Tectona is commonly called teak tree. it is common in tropical deciduous forests along with Butea, Bombax, Shorea (Sal), Acacia (khair) etc.
In India, tropical deciduous forests occur in both plains and low hilly areas of North as well as South India.

Carbon Monoxide is formed by improper or incomplete combustion and is generally emitted from vehicles.

Reforestation is restocking the destroyed forest by planting new trees. We should plant at least as many trees as we cut.

Burning of coal produces lot of carbon dioxide because solid fuel does not burn as efficiently as liquid or gaseous fuels.

The green scum seen in the fresh water bodies is due to blue green algae and green algae.

This is the reason, bones of humans and animals have been found from prehistoric period.

Eichhornia is commonly known as water hyacinth and has been the most notorious aquatic weed found all over the world.

Sewage discharge in water bodies leads to organic loading or occurrence of excess organic matter inside water body.
Its putrefaction decreases dissolved oxygen leading to competition for oxygen among fishes. Also blue green algae bloom and increase in number and release toxins. Both toxicity and decreased oxygen level kill aquatic animals, like fishes.