How is our quality of life affected if, say instead of 20,000 we have only 15,000 species of ants on earth ?

How many of the following statements are CORRECT ? I. India is one of the 12 megadiversity countries of the world. II. India has only 8.1 percent of the worl's land area. III. Nearly 45,000 species of animals and twice as many as plants have been recorded from lndia. IV. According to May's global estimates , only 22 percent of the total species have been recorded so far. v. Nature's biological the library is burning even before we catalogued the titles of all books stocked there.

Water is a universal solvent. But alcohol also dissolves most of the substances soluble in water. Boiling point of water is 100^(@)C and that of alcohol is 80^(@)C . The specific heat of water is much higher than the specific heat of alcohol. (a) List out three possible differences if instead of water as the liquid in our body we had alcohol. (b) What value can you derive from this special property of water and its innumerable uses in sustaining life on earth?

Ram was a daily wage worker in a factory. He was suffering from Cancer. On hearing this, most of his co-workers, started avoiding him under the impression that it was a contagious disease. When Prof. Srivastava came to know about this, case, he took him to a leading radiologist, who examined him and told that it was at the beginning stage. He advised that it could be easily cured and also certified that it was not a communicable disease. After this, Ram was given proper treatment by the doctor and got cured completely. (1) How is mean life of a radioactive element related to its half life? (2) A radioactive sample has activity of 10,000 disintegrations per second after 20 hours . After next 10 hours, its activity reduces to 5,000 dps. Find out its half - life and initial activity.