Skip to main content
Super TutorResources
Chapter 4 of 15
QuestionsNotesFlashcardsSummaryFormulasQuizConceptsSyllabusPlan
Revision Notes

Molecular Basis of Inheritance

Maharashtra Board · Class 12 · Biology

Quick revision notes for Molecular Basis of Inheritance — Maharashtra Board Class 12 Biology. Key concepts, formulas, and definitions for last-minute revision.

42 questions28 flashcards5 concepts

Interactive on Super Tutor

Studying Molecular Basis of Inheritance? Get the full interactive chapter.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan — built for revision notes and more.

Try Super Tutor — Free

1,000+ Class 12 students started this chapter today

Key Topics to Revise

1

Discovery and Structure of DNA

  • Friedrich Miescher (1869) first isolated 'nuclein' from white blood cells in pus, which was later identified as DNA
  • DNA is composed of nucleotides containing deoxyribose sugar, phosphate group, and nitrogenous bases (A, T, G, C)
  • Watson-Crick double helix model: antiparallel strands held together by hydrogen bonds (A=T, G≡C)
2

DNA as Genetic Material - Experimental Proofs

  • Griffith's experiment (1928): Transformation principle in Streptococcus pneumoniae (R-strain to S-strain)
  • Avery, McCarty, and MacLeod (1944): Proved DNA is the transforming principle using enzyme treatments
  • Hershey-Chase experiment (1952): Used radioactive ³²P (DNA) and ³⁵S (protein) to prove DNA is genetic material
3

DNA Packaging

  • Prokaryotic packaging: Circular DNA forms loops and supercoils with help of HU proteins and DNA gyrase
  • Eukaryotic packaging: DNA wraps around histone octamers to form nucleosomes (beads-on-string)
  • Histone octamer contains 2 each of H2A, H2B, H3, and H4; H1 acts as linker
4

DNA Replication

  • Semiconservative replication: Each new DNA molecule has one old and one new strand
  • Meselson-Stahl experiment (1958) proved semiconservative nature using ¹⁵N and ¹⁴N isotopes
  • Process steps: Initiation at origin → Unwinding by helicase → Primer synthesis → DNA synthesis

Get complete notes with diagrams and examples

Full Notes

Key Concepts

Friedrich Miescher first discovered nuclein (DNA)DNA must be compacted to fitSemiconservative replication occurs in SProcess of copying genetic information fromThe genetic code is a triplet

Frequently Asked Questions

What are the important topics in Molecular Basis of Inheritance for Maharashtra Board Class 12 Biology?
Molecular Basis of Inheritance covers several key topics that are frequently asked in Maharashtra Board Class 12 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.
How to score full marks in Molecular Basis of Inheritance — Maharashtra Board Class 12 Biology?
Understand the core concepts first, then work through the 42 practice questions available for this chapter. Revise formulas and definitions regularly, and use flashcards for quick recall before the exam.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.

More resources for Molecular Basis of Inheritance

All 15 chapters — Maharashtra Board Class 12 Biology Revision Notes

For serious students

Get the full Molecular Basis of Inheritance chapter — for free.

Quizzes, flashcards, AI doubt-solver and a step-by-step study plan for Maharashtra Board Class 12 Biology.

Try Super Tutor Free
Try the full chapter — Free