CSIR-NET Unit 3 Revision & Study Plan – Top 10 Tips & Tricks

A new initiative by Biotecnika where we are on a mission to help you conquer the CSIR NET Exam like a warrior. We are already done with Unit 1 & Unit 2 and now we move on to CSIR-NET Unit 3 Revision & Study Plan For CSIR NET Life Sciences and hope to progress to Unit 13 and help you all achieve your dreams!

Unit 3 deals with the fundamental processes of life itself. It’s a complete concept based and hence you can score well. The books mentioned below are the ones that will help you score well.

Books you may refer to! 

  • Molecular Biology of the Gene by James D. Watson
  • Molecular Biology of the Cell, B. Alberts
  • Lehninger’s Principles of Biochemistry by David L. Nelson and Michael M. Cox
  • Cell and Molecular Biology: Concepts and Experiments by Gerald Karp
  • Molecular Cell Biology by Harvey Lodish, Arnold Berk, Chris A. Kaiser

Why you should NOT SKIP Unit 3?

  • Essential since includes all fundamental processes,  comparatively simple, interesting and scoring unit.
  • On average, 10 – 12 questions are asked including part B and Part C
  • Concepts are merged with units 1, 2, 4, 8 and 13 to frame questions

Important topics to be covered

Prokaryotic and eukaryotic DNA replication

  • 3 Models of replication
  • Meselson & Stahl  Experiment
  • Prokaryotic & eukaryotic origins
  • DNA polymerases
  • Other enzymes involved in replication
  • Telomerase

DNA Repair pathways –

  • Types of mutations and other DNA damages
  • DNA damage repair mechanisms
  • Enzymes involved
  • SOS repair

RNA transcription –

  • Types of RNA
  • RNA polymerases
  • Transcription factors
  • Role of –
  • Promoters
  • Enhancers
  • Activators
  • Repressors
  • Mediators

Post-transcriptional processing-  

  • Capping
  • Polyadenylation
  • RNA splicing
  • RNA Editing

Genetic code – 

  • Start codons
  • Stop codons

Translational inhibitors- 

  • The action of different antibiotics

Operon model – 

  • Lac operon –
  • Catabolite repression
  • Trp operon –
  • Attenuation Regulation in Trp operon
  • Mutation effects on operon

Eukaryotic gene regulation – 

  • Chromatin structure
  • Role of Methylation & Acetylation in gene expression
  • Gene regulation during development- can be merged with Unit- 5

Semi-conservative model of DNA replication & Meselson Stahl Experiment

  • Both Numerical and statement-based questions including hypothetical ones are often asked in Part C
  • Cover all the three models of DNA replication- Conservative, Semi- conservative and Dispersive
  • Results of caesium chloride density gradient centrifugation method as evidence of semi-conservative model

Types of DNA polymerases (NOT TO BE SKIPPED)

  • Make comparison tables to remember the names and functions of different DNA polymerases in prokaryotes & eukaryotes respectively.
  • Fidelity of DNA polymerases

Enzymes at Replisome 

  • Make & Keep a colorful diagram of replication fork depicting bidirectional mode of replication
  • Both Numerical and statement questions are asked based on bidirectional replication model and Okazaki fragments.
  • Enlist all the enzymes working at replication fork.
  • Match the following type questions are asked on the basis of functions of different enzymes

PROKARYOTIC & Eukaryotic replication mechanisms

  • Replication events should be learned through flow charts or simple diagrams
  • The sequence of replication events is combined with the cell cycle from Unit- 2 forming the graphical-based questions in Part- C

DNA repair pathways 

  • Remember three main categories for DNA repair Pathways

DNA damage and DNA repair pathways 

  • Use Comparison tables for differentiating between-
  • Repair mechanisms
  • Translesion polymerases and SOS repair mechanism
  • Don’t miss types of mutations and mutagenic agents
  • Questions are usually framed merging DNA repair mechanisms with the mutations


  • Prokaryotic and eukaryotic transcription mechanisms

Quick Tips during UNIT-3 REVISION

Make descriptive and colourful charts of various factors involved in –

  • Replication
  • Transcription
  • Translation
  • Proteins which are part of –
  • Regulatory mechanisms
  • Inhibitory mechanisms
  • Don’t miss any subtopic because the combination of statement-based questions sourced from different subunits are asked
  • Ensure to learn & master –
  • Recombinant DNA technology techniques from unit 13
  • Mutational concepts from Unit 8
  • Practice numerical type questions from –
  • Lac operon
  • Meselson & Stahl experiment

Whatever you do

Don’t skip ⇒ Revise Smart ⇒ Create Memory Milestones ⇒ Achieve Success

Sample Question Paper – Download link

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