What will happen if −
(a) Forests, scrub and other vegetation is reduced.
(b) Sewage carrying dangerous chemicals enters rivers.
(c) Birds eat insects which have been killed by insecticides.
(d) Poisonous substances are overused to prevent insects from destroying a crop.
(e) A dam is built in a famine-prone region.
What will happen if −
(a) Forests, scrub and other vegetation is reduced.
(b) Sewage carrying dangerous chemicals enters rivers.
(c) Birds eat insects which have been killed by insecticides.
(d) Poisonous substances are overused to prevent insects from destroying a crop.
(e) A dam is built in a famine-prone region.
(a) Forests and vegetation form the base of the food chain. If the vegetation gets reduced, many organisms such as animals and humans which are dependent on vegetation will face starvation. Also the balance of the nature will be disturbed such as decrease in rainfall, an increase in soil erosion and temperature. Many birds and animals will loose their shelter and will become more susceptible to predators.
(b) If sewage carrying dangerous chemicals mixes with rivers, it will contaminate the river water. The organisms drinking contaminated water from it will suffer from various diseases. When agricultural land is watered with the contaminated river water, it will affect the fertility of the soil badly and also will kill the useful microbes present in the soil.
(c) When a bird eats the insect killed with insecticides, the insecticide will enter the body of the bird, which can cause harm to the bird. When the bird is further consumed by a predator, the insecticide is passed on to the body of that organism causing harm to it.
(d) Excessive use of poisonous substances over a long period may affect the quality of the soil and may also adversely affect the crop production.
(e) Dams are built in famine−prone areas to control floods. Some of their capacity is kept empty so that during flood conditions excess water is stored in the dams.
(a) Forests and vegetation form the base of the food chain. If the vegetation gets reduced, many organisms such as animals and humans which are dependent on vegetation will face starvation. Also the balance of the nature will be disturbed such as decrease in rainfall, an increase in soil erosion and temperature. Many birds and animals will loose their shelter and will become more susceptible to predators.
(b) If sewage carrying dangerous chemicals mixes with rivers, it will contaminate the river water. The organisms drinking contaminated water from it will suffer from various diseases. When agricultural land is watered with the contaminated river water, it will affect the fertility of the soil badly and also will kill the useful microbes present in the soil.
(c) When a bird eats the insect killed with insecticides, the insecticide will enter the body of the bird, which can cause harm to the bird. When the bird is further consumed by a predator, the insecticide is passed on to the body of that organism causing harm to it.
(d) Excessive use of poisonous substances over a long period may affect the quality of the soil and may also adversely affect the crop production.
(e) Dams are built in famine−prone areas to control floods. Some of their capacity is kept empty so that during flood conditions excess water is stored in the dams.
