MENDELIAN THEORY OF INHERITANCE

INTRODUCTION

  • Gregor Johann Mendel – Father of Modern Genetics.
  • He studied approximately 29000 pea plants to demonstrate inheritance of traits following certain laws.
  • For seven years, Mendel bred pea plants and recorded inheritance patterns in the offspring.
  • He studied seven characteristics in the garden pea.
mendel's first law - Liberal Dictionary

WHY A PEA PLANT

  • Flower structure of pea plant ensured self pollination and also well defined male and female characteristics.
  • Single season crop.
  • Emasculation and pollination of pea plants is quiet easy.
  • Reproduces sexually
  • In varieties available , several characters has 2 contrasting forms which were easily distinguishable from each other
3d model pea pod flower

Mendel’s Plant Breeding Experiments

  • Particulate Hypothesis of Inheritance
  • Parents pass on to their offspring separate and distinct factors (today called genes) that are responsible for inherited traits
  • Understood that there was something that carried traits from one generation to the next- “FACTOR”.

To test the particulate hypothesis, Mendel crossed true breeding plants that had two distinct and contrasting traits—for example, purple or white flowers.
What is meant by “true breeding?”

Biol 1020: Genetics

Typical breeding experiment

Mendelian Genetics ppt download

Mendel’s Laws of InheritanceMendel postulated three laws, which are now called after his name as Mendel’s laws of heredity.

These are:

Law of dominance and recessive

Law of segregation

Law of independent assortment

Mendelian Genetics — Principles of Inheritance & 3 Laws - Expii