Ans: (d)
299. Late blight of potato is caused by
     (a) Puccinia
     (b) Pennisetum
     (c) Phytophthora
     (d) Erysiphe
Ans: (c)
300. Aphids are
     (a) insect pests
     (b) fungal pests
     (c) bacterial pests
     (d) viral pests
Ans: (a)
301. Biological control is to check growth of
     (a) plants
     (b) animals
     (c) weeds
     (d) one pest by another
Ans: (d)
302. Nephantis is popularly called
     (a) coconut caterpillar
     (b) brown plant hopper
     (c) tobacco caterpillar
     (d) pulse beetle
Ans: (a)
303. The science dealing with diseases of plants is called
     (a) Plant anatomy
     (b) Plant ecology
     (c) Plant pathology
     (d) Plant morphology
Ans: (c)
304. The small pox vaccine was discovered by
     (a) Louis Pasteur
     (b) Edward Jenner
     (c) John
     (d) Harvey
Ans: (b)
305. The influenza vaccine was discovered by
     (a) Salk
     (b) Khorana
     (c) Mittel
     (d) None of the above
Ans: (a)
306. The latest drug for cancer is obtained from
     (a) Strychnos nuxvomica
     (b) Vinca rosea
     (c) Atropa belladona
     (d) Phyllanthus niruri
Ans: (b)
307. AIDS is caused by the organisms which are
     (a) bacteria
     (b) fungi
     (c) viruses (HTLV III)
     (d) Protozoa
Ans: (c)
308. The germ theory of diseases was put forward by
     (a) Louis Pasteur
     (b) Luister
     (c) Leuwenhoek
     (d) Flemming
Ans: (a)