289. The sea horse is an example of:
      (a) fishes class
      (b) mammals class
      (c) reptiles class
      (d) mollusc class
Ans: (a)
290. Which of the following is a real fish? [UPPCS (Pre) 2004]
      (a) cray fish
      (b) flying fish
      (c) cuttle fish
      (d) silver fish
Ans: (b)
291. An artificial kidney works on the principle of:
     (a) diffusion
     (b) osmosis
     (c) dialysis
     (d) active transportation
Ans: (c)
292. Which one among the following nontoxic gases helps in formation of enzymes which ripen fruit?
      (a) Acetylene
      (b) Ethane
      (c) Methane
      (d) Carbon dioxide
Ans: (a)
293. The terrestrial species of Echinodermata are :
      (a) brittle - star
      (b) starfish
      (c) sea-lily
      (d) None of these
Ans: (d)
294. The most significant stimulant in the tea leaves is :
     (a) brucine
     (b) caffeine
     (c) phenylalanine
     (d) theine
Ans: (b)
295. The fishes are assumed to be healthy and more nourishable with comparison to another flesh animals because in
     the fish: [IAS (pre) 1999]
      (a) there exists multi unsaturated acid
      (b) there exists saturated fatty acid
      (c) there exists necessary vitamins
      (d) there exists more carbohydrate and protein
Ans: (a)
296. All living organisms are single eelled in their earliest history of life. Which of the following is an example of such a
     cell ?
      (a) Ovum
      (b) Sperm
      (c) Spermatocyte
      (d) Zygote