Chapter 18 of 41
Revision Notes
Molecular Inheritance and Gene Expression — Revision Notes
Telangana Open School (TOSS) · Class 12 · Biology
Molecular Inheritance and Gene Expression revision notes for Telangana Open School (TOSS) Class 12 Biology: 4 topics in quick points.
42 questions28 flashcards5 concepts
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Key Topics to Revise
1
Discovery of DNA as Genetic Material
- Griffith's experiment (1928) showed bacterial transformation: non-virulent R-strain became virulent when mixed with heat-killed S-strain.
- Avery, MacLeod & McCarty (1944) proved DNA is the 'transforming principle' by showing only DNA can cause transformation.
- Hershey-Chase experiment (1952) used radioactive labeling: DNA (labeled with P-32) entered bacteria, not protein (labeled with S-35), proving DNA is genetic material.
2
Structure of DNA
- DNA is a double helix made of two antiparallel strands.
- Each nucleotide has deoxyribose sugar, phosphate group, and nitrogenous base (A, T, G, C).
- A pairs with T via 2 hydrogen bonds; G pairs with C via 3 hydrogen bonds.
3
RNA and Its Types
- RNA is single-stranded, contains ribose sugar and uracil instead of thymine.
- Three main types: mRNA, tRNA, rRNA.
- mRNA carries genetic code from DNA to ribosome.
4
Central Dogma and Gene Expression
- Central Dogma: DNA → RNA → Protein.
- Replication: DNA makes a copy of itself.
- Transcription: DNA to mRNA in nucleus.
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Full NotesKey Concepts
Experiments by GriffithDNA is a double helix madeGenetic information flows from DNA →Not all genes are active atThe genetic code is a set
Frequently Asked Questions
What are the important topics in Molecular Inheritance and Gene Expression for Telangana Open School (TOSS) Class 12 Biology?
Key topics in Molecular Inheritance and Gene Expression include Discovery of DNA as Genetic Material, Structure of DNA, RNA and Its Types, Central Dogma and Gene Expression. Study these first, then practise questions on each for the Telangana Open School (TOSS) Class 12 board exam.
How should I revise Molecular Inheritance and Gene Expression for the Telangana Open School (TOSS) Class 12 board exam?
Learn the core ideas first, then work through the 42 practice questions on Molecular Inheritance and Gene Expression. Revise 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.
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