पादप जैव प्रौद्योगिकी एवं आणविक जीवविज्ञान

Classification of DNA molecular markers into hybridization-based vs PCR-based:

• Restriction Fragment Length Polymorphism (RFLP) is a non-PCR, hybridization-based marker system utilizing restriction digestion and Southern blotting.
• Amplified Fragment Length Polymorphism (AFLP), Simple Sequence Repeats (SSR / Microsatellites), and Random Amplified Polymorphic DNA (RAPD) are all PCR-dependent markers requiring in vitro enzymatic DNA amplification.
  Because Options 1, 2, and 4 all contain the non-PCR marker RFLP, Option 3 (AFLP, SSR and RAPD) is the only combination where all three markers are PCR-based.

Technical characteristics of Random Amplified Polymorphic DNA (RAPD):

• True: RAPDs are dominant markers (scored as presence vs absence of a band, unable to distinguish homozygotes from heterozygotes).
• True: RAPD utilizes a single short arbitrary oligonucleotide primer (typically a 10-mer decamer) that primes in both directions on complementary inverted sites across the genome.
• False: RAPD amplifies random, non-specific loci across the genome rather than predefined specific target loci.
• True: Because 10-nucleotide primers have low melting temperatures ($T_m$), PCR annealing is conducted at low stringency ($34^\circ\text{C} - 37^\circ\text{C}$).

History and establishment of NCBI:

• The National Center for Biotechnology Information (NCBI) was formally established on November 4, 1988, as a division of the National Library of Medicine (NLM) at the National Institutes of Health (NIH) in Bethesda, Maryland, USA.
• It was established through legislation sponsored by US Congressman Claude Pepper to advance computerized information processing for molecular biology and biotechnology.