... chemical is added to make bacterial cells permeable to... | Agrigyan

• Father of Indian DNA Fingerprinting:
• Dr. Lalji Singh (1947–2017), former Director of the Centre for Cellular and Molecular Biology (CCMB, Hyderabad) and Vice-Chancellor of Banaras Hindu University (BHU):
• Isolated the Banded Krait Minor (Bkm) satellite DNA and developed the indigenous Bkm-derived probe for DNA fingerprinting in 1988.
• This breakthrough established forensic DNA analysis in India, accepted in legal courts for paternity disputes and murder investigations.
• nalysis:
• (Dr. Lalji Singh): Correct.

Correct option: (3) Dr. Lalji Singh

• Enzymatic Activities:
• Restriction Endonucleases (Type II):
• EcoRI recognizes and cleaves: $5'\text{-G}^\downarrow\text{AATTC-}3'$
• BamHI recognizes and cleaves: $5'\text{-G}^\downarrow\text{GATCC-}3'$
• HindIII recognizes and cleaves: $5'\text{-A}^\downarrow\text{AGCTT-}3'$
• DNA Polymerase I (Pol I):
• multi-functional enzyme with $5'\rightarrow 3'$ polymerase activity, $3'\rightarrow 5'$ proofreading exonuclease activity, and $5'\rightarrow 3'$ nick translation exonuclease activity.
• It does NOT recognize palindromic restriction target sites and does not perform sequence-specific internal cleavage.
• nalysis:
• (Pol I): Correct.

Correct option: (4) Poll

• Properties and Action of TdT:
• Terminal Deoxynucleotidyl Transferase (TdT) is a template-independent DNA polymerase.
• It catalyzes the repetitive addition of deoxynucleoside triphosphates (dNTPs) onto the $3'\text{-OH}$ terminus of single-stranded or double-stranded DNA molecules without requiring a template strand.
• Biotechnological Applications:
• Used in homopolymer tailing (e.g., adding poly-dG or poly-dC tails to vectors and cDNAs for blunt-end cloning).
• Labeling $3'$ ends of DNA with radioactive nucleotides or digoxigenin for non-radioactive probes.
• TUNEL assay for detecting apoptotic DNA fragmentation.
• nalysis:
• (Terminal Deoxynucleotidyl Transferase): Correct.

Correct option: (4) Terminal Deoxynucleotidyl Transferase