RPSC Agriculture Research Officer (Entomology) - 2022

Properties 2 and 3 are correct physical attributes of lac (fusible on heat, excellent natural adhesive); statements 1, 4, 5, and 6 are incorrect because: lac is completely insoluble in water but soluble in alcohol (1 is wrong); possesses strong binding properties with alcohol (4 is wrong); is a poor conductor / excellent insulator of heat and electricity (5 is wrong); and dissolves readily in weak alkalies like aqueous ammonia or sodium carbonate (6 is wrong).

• 1, 4, 5 and 6 only: Correct code identifying all four false statements.
• 2, 4 and 5 only: Incorrect because statement 2 is true.
• 1, 2, 5 and 6 only: Incorrect because statement 2 is true.
• All of the above statements: Incorrect because 2 and 3 are true.

Steinernema glaseri is a famous entomopathogenic nematode (EPN) of the family Steinernematidae that parasitizes and kills subterranean insect grubs, famously applied against the Japanese beetle (Popillia japonica) with symbiotic bacteria Xenorhabdus.

• parasitic nematode: Exact biological classification of Steinernema glaseri.
• parasitic insect: Includes wasps like Tiphia vernalis.
• parasitic bacteria: Milky spore disease is caused by Paenibacillus popilliae.
• parasitic fungi: Includes Metarhizium and Beauveria.

MRL stands for Maximum Residue Limit, defined by the Codex Alimentarius Commission and national food authorities as the maximum concentration of a pesticide residue legally permitted in or on food commodities or animal feeds.

• Maximum Resistance Level: Erroneous term.
• Minimum Residue Limit: Incorrect terminology.
• Maximum Residue Limit: Official statutory expansion of MRL adopted in pesticide regulations and food safety standards.
• Maximum Residue Level: Informal usage, but 'Limit' is the official standard statutory term.