12th Standard CBSE - Biology - Biodiversity and Conservation

Buy 12th Biology MCQ Online Test CBSE Practice test pack

Question - 1

In 1984, the Bhopal gas tragedy took place because methyl isocyanate

  • A Reacted with ammonia
  • B Reacted with CO2
  • C Reacted with water
  • D Reacted with DDT

Question - 2

Lead conc. in blood is considered alarming if it is

  • A 30 \(\mu \)g/100 ml
  • B 4 - 6 \(\mu \)g/100 ml
  • C 10 \(\mu \)g/100 ml
  • D 20 \(\mu \)g/100 ml

Question - 3

Blood analysis of a patient reveals an usually high quantity of carboxyhaemoglobin content. Which of the following conclusions is most likely to be correct? The patient has been inhaling polluted air containing unusually high content of

  • A Chloroform
  • B Carbondioxide
  • C Carbon monoxide
  • D Carbon disulphide

Question - 4

Common indicator organism of water pollution is

  • A Eichhornia crassipes
  • B Escherchia coli
  • C Entamoeba histolytica
  • D Lemna pancicostata

Question - 5

The noise produced in office is normally at the level of

  • A 20 db
  • B 30 db
  • C 40 db
  • D 60 db

Question - 6

Nitrogen oxides produced from the emission of automobiles and power plants, are the source of fine air born particles which lead to

  • A Photochemical ring
  • B Dry acid deposition
  • C Industrial smog
  • D Wet acid deposition

Question - 7

A lake with an inflow of domestic sewage rich in organic waste may result in

  • A Drying of the lake very soon due to algal bloom
  • B An increased production of fish due to lot of nutrients
  • C Death of fish due to lack of oxygen
  • D Increased population of aquatic food web organisms.

Question - 8

Minamata disease was caused due to the consumption of

  • A Sea food containing lot of cadmium
  • B Fish contaminated with mercury
  • C Oysters with lots of pesticide
  • D Sea food contaminated with selenium

Question - 9

The world environment day is celebrated on

  • A 6th of June
  • B 5th of June
  • C 6th of August
  • D 5th of May

Question - 10

Bhopal gas tragedy 1984 was caused by the leakage of gas__

  • A Hydrogen cyanide
  • B Ammonia
  • C 2, 4-Dichlorophenoxy acetic acid
  • D Methyl isocyanate
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