Structure of DNA and RNA — Prelims Strategy

Prelims Strategy

To excel in NEET questions on DNA and RNA structure, a multi-pronged strategy is essential. Firstly, master the basic components: clearly differentiate between nucleotides and nucleosides, and know the three parts of a nucleotide (sugar, phosphate, base).

Crucially, memorize the specific sugars (deoxyribose vs. ribose) and bases (T in DNA, U in RNA). Secondly, understand the bonding: know that phosphodiester bonds form the backbone, and hydrogen bonds link complementary bases.

Remember the exact number of hydrogen bonds (A=T with two, G≡C with three) as this is a common trap. Thirdly, grasp the DNA double helix features: antiparallel strands, major/minor grooves, and the dimensions (3.

4 nm per turn, 10 bp per turn). Fourthly, apply Chargaff's rules flawlessly for numerical problems; practice calculating base percentages. Finally, know the functions of different RNA types (mRNA, tRNA, rRNA) and how their structure relates to their role.

For conceptual questions, read each option carefully, looking for subtle inaccuracies. For numerical problems, write down the given values and apply the rules systematically. Avoid rushing, as small errors in counting or recalling specific details can lead to incorrect answers.