Lecture on Molecular Basis of Inheritance

Introduction

• Topic: Molecular Basis of Inheritance
• Part of Genetics
• Two main chapters in Genetics: Principles of Inheritance & Variation, Molecular Basis of Inheritance
• Focus on the largest molecule in the body: DNA

Importance of the Chapter

• Highly significant unit in the syllabus
• Can have 9-10 questions from this chapter
• Study of large molecules: DNA -> RNA conversion, DNA Fingerprinting, Human Genome Project
• Begins with the basic structure of DNA

Structure of DNA

• Revisiting the structure of DNA learned in biomolecules
• Today's Targets:
  • Structure of DNA
  • Packaging of DNA
  • Search for Genetic Material
• Following classes will cover replication and transcription

DNA and RNA Basics

• DNA: Deoxyribonucleic Acid, largest molecule
• DNA -> Polymer, made of nucleotides
• Nucleotides: Consists of three components
  • Phosphoric Acid
  • Deoxyribose Sugar
  • Nitrogenous Base
• Two types of Nitrogenous Bases
  • Purines: Adenine (A) and Guanine (G)
  • Pyrimidines: Thymine (T) and Cytosine (C)
• RNA: Ribonucleic Acid
  • Has Ribose Sugar instead of Deoxyribose
  • Contains Uracil (U) instead of Thymine

Genetic Material Properties

• Stability (Chemically and Structurally)
• Ability to replicate
• Scope for slow mutations
• Ability to express itself

DNA Extraction and History

• First extracted from owl nucleus
• Named