It is thought that the concentration of CO2 in the year 1890 was around:

Related Mcqs:

1. It is thought that the concentration of CO2 by the year 2040 shall reach:

   A. 400 ppm
   B. 500 ppm
   C. 475 ppm
   D. 450 ppm

2. The maximum amount of CO2 fixed by green plants by way of photosynthesis in a year is:

   A. 9 x 1013 kg
   B. 8 x 1012 kg
   C. 9 x 1011 kg
   D. 8 x 1010 kg

3. If there were no CO2 in the earth’s atmosphere, the temperature of earth’s surface would have been:

   A. same as present
   B. Less than the present
   C. Higher than the present
   D. Dependent on the amount of O2 in the atmosphere

4. Checking of re-radiating heat by atmospheric dust water vapour, ozone, CO2 is known as:

   A. Green house effect
   B. Radioactive effect
   C. Ozone layer effect
   D. Solar effect

5. In submerged hydrophytes entry of CO2 is through:

   A. Epidermis as dissolved CO2
   B. Epidermis as carbonates only
   C. Epidermis as carbonates only
   D. Both (b) and (c)

6. The average amount of CO2 in atmosphere is:

   A. 0.30%
   B. 0.00%
   C. 3.00%
   D. 0.03%

7. The concentration of SO2 in the atmosphere is around:

   A. 0.01 ppm
   B. 0.001 ppm
   C. 0.5 ppm
   D. 0.75 ppm

8. Today, concentration of green house gases is high because of:

   A. Use of refrigerator
   B. Increased combustion of oil and coal
   C. Deforestation
   D. All the above

9. Exposure of plants to high fluoride concentration results in necrosis or chlorosis characteristics in:

   A. Petiole but not in lamina
   B. Only mid rib of lamina
   C. Leaf tip and leaf margin
   D. Stems tips only

10. Acid rain is mainly caused by increased concentration (in atmosphere) of:

    A. Ozone and dust
    B. NH3 and SO3
    C. CO and SO3
    D. NO2 and SO2