Last seen: Jan 25, 2021
(i) Intensive cropping; (ii) planting grasses and xerophytes; (iii) Terrace farming; (iv) Proper drainage canals around the fields.
The removal of top fertile layer of soil by the action of air, wind, water etc. is called soil erosion.
Soil is formed by breaking down of rocks at or near the surface of earth through various physical, chemical and biological processes by various factor...
Discharge of sewage, industrial wastes, hospital wastes, chemical fertilisers etc. into the rivers and streams pollutes these fresh water sources.
Major sources of fresh water in the city/town/village are ground water, rivers, streams, lakes, etc.
Plants require water for photosynthesis. All cellular processes occur in a water medium. Transportation of substances in our body takes place in dis...
1. Harmful gases released from various industries. 2. Burning of fossil fuels like coal and petroleum. 3. Burning of diesel and petrol in vehicles...
During day time water from different sources like river, sea etc. rises in the form of water vapour and goes into the air. At a particular height the ...
The uneven heating of the atmosphere in different regions of the earth causes wind. The air above the land gets heated faster and starts rising. As th...
The presence of ozone in the upper layer of atmosphere protects life from harmful ultraviolet radiations. Atmosphere maintains the temperature on the ...
Atmosphere on Venus and Mars have high percentage (approx. 95%) of CO2 which does not support life, while atmosphere of our earth consists of various ...
(a) Virus causes chickenpox. (b) One precaution of avoiding spread of chickenpox is to stay away from public places when one is suffering from it. ...
(a) Malaria is caused due to the protozoa named Plasmodium. (b) Two ways to prevent malaria are (i) Clear all breeding grounds of mosquitoes i.e.,...
(a) Fever is not a disease it is a symptom. (b) Antibiotics are medicines advised to be taken only when the immune system of a patient is unable to ...
(a) Balanced diet provides all the nutrients to our body in appropriate amount and keeps our body healthy. (b) Heart diseases and obesity. (c) The...
(a) HIV virus. (b) Two preventive measures of AIDS are use of disposable injections, scanning of blood before transfusion for HIV. (c) Students sh...
Bacteria - Tuberculosis, typhoid, diarrhoea, cholera Virus - Polio, AIDS, chickenpox Protozoa - Malaria, amoebiasis, kala-azar, sleeping sickness ...
1. Malaria - Mosquito bite (female Anopheles mosquito carries protozoa) 2. AIDS - Infected blood, semen, mother’s milk, from mother to foetus. 3. ...
Principles of treatment for diseases are: (1) To reduce the effect of the diseases. (2) To kill the cause of the disease i.e., to kill the microbe...
Disease can be defined as the state of human health which is not at ease is not comfortable. During disease, the functioning or appearance of one or m...