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The given graph shows changes in various...

The given graph shows changes in various factors (L, Mand N) present in a water body after the sewage is discharged at a point X.

Refer to the given graph and select the incorrect statement regarding L, Mand N.

A

L could be bacteria which increase tremendously in number due to addition of sewage waste.

B

M corresponds to biological oxygen demand which decreases due to the accumulation of sewage in water.

C

N could be aquatic animals like fish, which die on account of non-availability of dissolved oxygen.

D

Both A and C

Text Solution

Verified by Experts

The correct Answer is:
B
BOD or biological oxygen demand is a measure of dissolved oxygen required by aerobic decomposers for the biochemical degradation of the organic meterials present in water body. Discharge of sewage into the water body will result in rise of BOD because decomposer organisms consume a lot of oxygen.
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