MCAER PG CET 2026 AGRIL ENTOMOLOGY

 

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MCAER PG CET 2026

Subject: Agricultural Entomology (Hard Level)

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1. The 'Pleuropodium' in insect embryos is a modification of which embryonic segment?

A) Mandibular segment

B) Maxillary segment

C) Prothoracic segment

D) First abdominal segment

Answer: D. The pleuropodia are glandular organs on the first abdominal segment of the embryo, often involved in secreting enzymes to dissolve the eggshell during hatching.

2. [PYQ 2021] Which of the following is a 'Reverse Genetics' tool used to silence specific genes in insects?

A) PCR

B) RNA interference (RNAi)

C) ELISA

D) Northern Blotting

Answer: B. RNAi is a powerful reverse genetics tool that allows researchers to study gene function by degrading the target mRNA, effectively "silencing" the gene.

3. In the Malpighian tubules of most terrestrial insects, the primary nitrogenous waste is actively transported as:

A) Ammonium nitrate

B) Potassium acid urate

C) Urea

D) Glutamine

Answer: B. Insects convert ammonia into uric acid, which is secreted into the tubules as potassium acid urate to conserve water.

4. Which type of haemocyte is primarily responsible for 'Encapsulation' of large foreign bodies like parasitoid eggs?

A) Prohaemocytes

B) Plasmatocytes & Lamellocytes

C) Oenocytoids

D) Spherule cells

Answer: B. Plasmatocytes and Lamellocytes (in Diptera) flatten and layer around large invaders to form a capsule.

5. [PYQ 2023] The 'Economic Injury Level' (EIL) is mathematically expressed as (where C=Cost, V=Value, I=Injury, D=Damage):

A) EIL = C / (V × I × D)

B) EIL = (V × I) / C

C) EIL = C × V × I

D) EIL = D / C

Answer: A. Pedigo’s formula states EIL = C / (V × I × D × K), where K is the efficiency of control.

6. The 'Filter Chamber' is a characteristic modification of the alimentary canal in which insect group?

A) Orthoptera

B) Hymenoptera

C) Hemiptera (Homoptera)

D) Coleoptera

Answer: C. Fluid-feeding insects (sap-suckers) use a filter chamber to bypass excess water and sugar directly from the foregut to the hindgut.

7. 'Dyar's Law' relates to which aspect of insect growth?

A) Increase in body weight

B) Increase in head capsule width

C) Number of eggs laid

D) Speed of nerve impulse

Answer: B. Dyar's Law states that the head capsule of caterpillars grows in a geometric progression (usually 1.4 ratio) at each molt.

8. The synthetic pyrethroid 'Deltamethrin' acts primarily on which part of the nervous system?

A) Acetylcholinesterase enzyme

B) GABA receptors

C) Sodium channels (keeps them open)

D) Octopamine receptors

Answer: C. Pyrethroids are axonic poisons that prevent the closure of voltage-gated sodium channels, leading to repetitive firing.

9. Which pheromone is known as the 'Queen Mandibular Pheromone' (QMP) in Honeybees?

A) 9-ODA

B) Bombykol

C) Geraniol

D) Civetone

Answer: A. 9-oxo-2-decenoic acid (9-ODA) is the primary component of QMP that suppresses worker reproduction.

10. The phenomenon where an unfertilized egg develops into a male insect is called:

A) Thelytoky

B) Arrhenotoky

C) Amphitoky

D) Polyembryony

Answer: B. Arrhenotoky is a form of parthenogenesis where males are produced from unfertilized eggs (common in Hymenoptera).

Check the detailed explanations provided under each question above.