Given below are two statements - one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Between organophosphorus pesticides malathion and parathion, the former is more toxic than the latter.
Reason (R): Malathion is hydrolyzed by enzymes possessed by mammals to produce relatively non-toxic products.

Correct option is D

Explanation:
Assertion (A) is false; malathion is actually considered less toxic than parathion. Parathion is known for its higher toxicity to both humans and mammals. Therefore, the assertion that malathion is more toxic is incorrect. On the other hand, Reason (R) is true. Malathion does undergo hydrolysis by certain enzymes in mammals, resulting in the formation of less harmful or non-toxic products, which contributes to its lower overall toxicity profile.
Information Booster:
· Organophosphorus Pesticides: These compounds, including malathion and parathion, work by disrupting the nervous system of pests, but they vary greatly in their toxicity levels.
· Toxicity Comparison: Parathion is significantly more toxic than malathion, making it a riskier choice in pest control applications.
· Hydrolysis Process: The enzymatic hydrolysis of malathion helps convert it into safer products, allowing for its use in agricultural practices with reduced risk to mammals.
· Environmental Considerations: The relatively non-toxic breakdown products of malathion contribute to its acceptance in integrated pest management strategies, as it poses less risk to non-target organisms.
· Regulatory Status: Due to the higher toxicity of parathion, its use is heavily restricted or banned in many countries, whereas malathion is still commonly used under regulated conditions.
· Public Health Implications: Understanding the differences in toxicity is crucial for assessing the risks associated with pesticide use, particularly for vulnerable populations.
Additional Information:
· Mechanism of Action: Both malathion and parathion inhibit acetylcholinesterase, leading to the accumulation of acetylcholine, which can result in neurological effects.
· Safety Practices: When handling these pesticides, appropriate safety measures must be taken to minimize exposure risks, especially with parathion.
· Monitoring Residues: Food products are regularly monitored for pesticide residues to ensure consumer safety and adherence to safety standards.
· Public Awareness: Knowledge about pesticide toxicity levels and their effects on health is essential for making informed choices in agricultural practices and pest management.