JEE Main · 2021 · 20 Jul 2021 · Shift 2 · Environmental Chemistry

Which one of the following gases is reported to retard photosynthesis ?

(A) $CO_{2}$
(B)CFCs
(C)CO
(D) $NO_{2}$ ✓ Correct

Answer: (D)

Solution

Carbon dioxide is the raw material of photosynthesis, chlorofluorocarbons act on stratospheric ozone rather than on leaves, and carbon monoxide is poisonous because it binds to haemoglobin in animals. Nitrogen dioxide enters a leaf through the stomata and dissolves in the cell sap to give nitrous and nitric acid, which bleach the chlorophyll and injure the leaf tissue, and the rate of photosynthesis falls. The gas reported to retard photosynthesis is nitrogen dioxide.

JEE Main · 2021 · 20 Jul 2021 · Shift 2 · Single correct option

Practise more: all JEE Main PYQs on Environmental Chemistry →

More JEE Main questions on Environmental Chemistry

The possibility of photochemical smog formation is more at
JEE Main 2023View solution →
Which of these reactions is not a part of breakdown of ozone in stratosphere?
JEE Main 2023View solution →
The delicate balance of $CO_{2}$ and $O_{2}$ is NOT disturbed by:
JEE Main 2023View solution →
Match List-I with List-II

List-I (Industry):
(A) Steel plants
(B) Thermal power plants
(C) Fertilizer industries
(D) Paper mills

List-II (Waste Generated):
(I) Gypsum
(II) Fly ash
(III) Slag
(IV) Bio-degradable Wastes

Choose the correct answer from the options given below:
JEE Main 2023View solution →
Given below are two statements :

Statement I : If BOD is 4 ppm and dissolved oxygen is 8 ppm , then it is a good quality water.
Statement II : If the concentration of zinc and nitrate salts are 5 ppm each, then it can be a good quality water.
In the light of the above statements …
JEE Main 2023View solution →
Match List I with List II

LIST I | LIST II
A. Nitrogen oxides in air | I. Eutrophication
B. Methane in air | II. pH of rain water becomes 5.6
C. Carbon dioxide | III. Global warming
D. Phosphate fertilisers in water | IV. Acid rain

Choose the correct answer from the options giv …
JEE Main 2023View solution →