Section 45 of The Protection of Plant Varieties and Farmers... | Agrigyan

• Base Editing: A precision genome editing technology developed by David Liu and colleagues (Komor et al., 2016; Gaudelli et al., 2017).
• Mechanism: Fuses a catalytically impaired Cas9 nickase (nCas9) or dead Cas9 (dCas9) to a nucleotide deaminase enzyme:
• Cytosine Base Editors (CBEs): Employ cytidine deaminases (e.g., APOBEC) to convert $C \rightarrow T$ ($G \rightarrow A$).
• Adenine Base Editors (ABEs): Employ engineered adenosine deaminases (TadA) to convert $A \rightarrow G$ ($T \rightarrow C$).
• Distinction: Directly creates single nucleotide substitutions without double-stranded DNA breaks (DSBs) or donor repair templates. (Correct answer: Option 4)

• Microcenters of Genetic Diversity:
• Small, geographically localized pockets (identified by N.I. Vavilov and Jack Harlan) that harbor exceptionally intense, concentrated genetic diversity and high rates of endemism within major centers of origin.
• Because they represent biodiversity hotspots facing rapid genetic erosion, microcenters are prioritized as the most critical and urgent locations for germplasm exploration and rescue missions. (Correct answer: Option 3)

• Centres of Origin of Agricultural Crop Species (Vavilovian Centres):
• China (Chinese Centre): Primary center of origin for Buckwheat (Fagopyrum esculentum) and Soybean $\rightarrow$ (IV)
• Hindustan (Indian Centre): Primary center of origin for Old World diploid cotton (Gossypium arboreum) and Pigeonpea $\rightarrow$ (I)
• South America (South American Centre): Center of origin for New World tetraploid cotton (Gossypium barbadense) and Potato $\rightarrow$ (V)
• Mediterranean Centre: Primary center of origin for Peppermint (Mentha piperita), durum wheat, and cabbage $\rightarrow$ (II)
• Asia Minor (Near Eastern Centre): Center of origin for Sweet chestnut, cultivated einkorn, and emmer wheat $\rightarrow$ (III)
• Systematic Match: (A)-(IV), (B)-(I), (C)-(V), (D)-(II), (E)-(III) corresponds to Option 3.

Correct option: (3) (A) - (IV), (B) - (1), (C) - (V), (DB) - (ID, (E) - (Ill)