263. Genetic engineering is the study of
(a) Science of cybernetics
(b) Science of human organism control
(c) Biochemical changes in DNA
(d) Heredity and law’s governing it
264. Shockley, Bardeen and Brattain are associated with the discovery of
(a) Transistor
(b) Loudspeaker
(c) Radar
(d) Television
265. Which of the following constituents pollutant exhaust is hazardous for man?
(a) Carbon dioxide
(b) Carbon monoxide
(c) Carbon particles suspended in air
(d) Lead particles
266. Which of the following can cause cancer as well as cure it depending upon its intensity and use ?
a) Chemical
(b) Tobacco
(c) Grapes
(d) Ionised Radiations
267. Greenhouse’ effect is due to the
(a) absorption of longwave radiations emitted by the earth by atmospheric carbon dioxide
(b) Depletion of ozone in the outer atmosphere
(c) Depletion of carbon dioxide in the atmosphere
(d) Excess of ozone in the outer atmosphere
268. Which of the following diseases is transmitted by sex chromosomes?
(a) Diabetes
(b) Scurvy
(c) Colour blindness
(d) Smallpox
269. The normal blood pressure of a human being must be
(a) 140/80
(b) 120/80
(c) 160/100
(d) 140/90
270. Which of the following pairs correctly recognises one of the softest and the hardest substances respectively ?
(a) Talc, diamond
(b) Talc, quartz
(c) Talc, topaz
(d) Quartz, diamond
271. Dr. Hargobind Khorana received the Nobel prize for the
(a) Discovery of famous double helix model of DNA
(b) Grouping of artificial genes
(c) Isolation of genes
(d) Discovery of the structure of RNA