Question

Which of the following statements about air pollution effects is/are correct?

1. Carbon monoxide binds with haemoglobin, preventing oxygen transport.

2. Ethylene accelerates fruit ripening and causes premature leaf fall.

3. Nitrogen oxides cause acid rain and respiratory issues.

• A. 1 and 2 only
• B. 2 and 3 only
• C. All are correct
• D. 1 and 3 only

Answer 1

Answer:

C. All are correct

• Correct Answer: Option C - All are correct

• Carbon monoxide binds with hemoglobin, preventing oxygen transport:m: This statement is correct. Carbon monoxide (CO) has a much higher affinity (approximately 210-250 times) for hemoglobin than oxygen does. When CO enters the bloodstream, it binds to hemoglobin, forming carboxyhemoglobin (COHb), which prevents the normal transport of oxygen to tissues and organs. This reduces the oxygen-carrying capacity of blood, potentially leading to hypoxia (oxygen deprivation) in tissues.

• Ethylene accelerates fruit ripening and causes premature leaf fall: This statement is also correct. Ethylene (C₂H₄) is a gaseous plant hormone that naturally regulates various aspects of plant growth, development, and senescence. However, when present in excess due to pollution, ethylene can accelerate fruit ripening (which is why it's commercially used to ripen fruits) and cause premature abscission (leaf fall), leading to reduced plant productivity and lifespan.

• Nitrogen oxides cause acid rain and respiratory issues: This statement is correct as well. Nitrogen oxides (NOₓ), primarily NO and NO₂, react with water, oxygen, and other chemicals in the atmosphere to form nitric acid, which contributes to acid rain. Acid rain damages buildings, monuments, aquatic ecosystems, and vegetation. Additionally, when inhaled, nitrogen oxides can irritate the respiratory system, causing inflammation of the airways, reduced lung function, and increased susceptibility to respiratory infections.