Question

Student to attempt either option (A) or (B): (A) Biotechnology has helped farmers to get pest-resistant cotton plants. Explain the technique adopted along with its mode of action.
OR
(B) Explain any two molecular diagnostic techniques that help to detect pathogens from suspected patient.

Hint:

Bt cotton contains bacterial genes for pest resistance. PCR and ELISA are reliable tools for molecular diagnostics.

Answer 1

(A) Step 1: The technique involves the use of Bt cotton, a genetically modified crop.
Step 2: It contains genes from Bacillus thuringiensis that produce Cry proteins. 
Step 3: When ingested by insect larvae, Cry proteins form pores in their midgut epithelium, causing cell lysis and death. 
Conclusion: This makes the cotton plant pest-resistant and reduces pesticide use. 
OR 
(B) Two molecular diagnostic techniques:

• PCR (Polymerase Chain Reaction): Detects the presence of pathogen DNA by amplifying it from minute quantities.
• ELISA (Enzyme-Linked Immunosorbent Assay): Detects antigens or antibodies using antigen-antibody interaction and enzyme-linked indicators.