Introduction to Genetics

Science of Heredity

A. J. S. McMillan

• Publisher: Pergamon
• Year: 2014
• Print ISBN: 9781483229140
• eBook ISBN: 9781483282510
• Topic: Biological Sciences
• Subtopic: Biophysics
• Index: Biological Sciences

Introduction to Genetics: Science of Heredity presents a linear programmed text about hereditary and genetics. This book discusses a variety of topics related to heredity and genetics, including chromosomes, genes, Mendelism, mitosis, and meiosis. Organized into six chapters, this book begins with an overview of some of the experiments that first provide an understanding of heredity and laid the foundation of the science of genetics. This text then provides detailed information about the cell and explains how the essential parts of it reproduce and divide. Other chapters consider how the chromosome theory can explain not only the facts of Mendelism, but also the many complications that arise in genetics. This book discusses as well the problems that can happen during the process of mitosis and meiosis. The final chapter deals with the practical problems that confront the plant breeder. This book is a valuable resource for teachers and students of biology.

CHAPTER ONE

Gregor Mendel and the Laws of Heredity

Publisher Summary

This chapter describes some of the experiments that first gave an understanding of heredity and laid the foundation of the modern science of genetics. The importance of Mendel’s work was recognized, and his discovery was accepted as one of the most fundamental and important that has been made in biology. Mendel liked growing plants in the monastery gardens, and he was interested in how they grew. He planned some experiments to see if he could discover laws governing the appearance of these different characters. The pollen is usually carried from one plant to another by bees or butterflies. This is known as cross-fertilization. A plant in which the female organs are fertilized by the male organs of the same flower is said to be self-fertilizing. A plant in which the female organs are fertilized by the male organs of another plant is said to be cross fertilizing.

IN THIS chapter we are going to describe some of the experiments that first gave an understanding of heredity, and laid the foundation of the modern science of genetics.

To get some idea of what is involved in genetics we cannot do better than look at some of the work of the man who first did experiments in heredity that showed clear and simply related results.

This man was Gregor Johann Mendel who taught physics in the school of the Augustinian monastery at Brünn in Austria (now Brno in Czechoslovakia). His main work was done between 1857 and 1865, and he published the results in a local journal in 1869.

After he was promoted to be head of his house, he did not have time to do any more experiments.

Mendel’s work, published in 1869, was not discovered until 1900 when a search of the literature for anything that might throw some light on the problems of heredity was made by Correns, Tschermak and de Vries.

The importance of his work was recognised at once, and his discovery was accepted as one of the most fundamental and important that has been made in biology.

The first man to do experiments that gave a clear answer to some of the problems of heredity was named …

Mendel

Mendel liked growing plants in the monastery gardens, and he was interested in how they grew. He studied his pea plants and wondered why some were tall and some dwarf, why some had red flowers and some white, why some seeds in a pod were wrinkled and some smooth.

He wanted to find out how these variations happened, and how they were inherited, or passed from parent to offspring when one generation followed another. He planned some experiments to see if he could discover laws governing the appearance of these different characters.

Mendel wanted to find out how … were inherited.

variations

Mendel’s basic work was with one plant, the garden pea (the scientific name is Pisum sativum), and was successful because he introduced some new principles into his work which had not been used before (also, he was fortunate in picking the garden pea to work with, as we shall see later).

Mendel’s work was successful because he introduced …

new principles

The first of Mendel’s new principles was that he worked with pure lines. That is, plants that had been inbred for long enough to m...

Table of contents

• Cover image
• Title page
• Table of Contents
• THE COMMONWEALTH AND INTERNATIONAL LIBRARY
• CERTIFICATE OF VALIDATION
• Copyright
• VALIDATION CERTIFICATE
• Author’s Preface
• Editor’s Preface
• This is not an ordinary book
• Introduction
• Chapter One: Gregor Mendel and the Laws of Heredity
• Chapter Two: Chromosomes and Genes
• Chapter Three: The Chromosome Theory and Mendelism
• Chapter Four: Accidents in Mitosis and Meiosis
• Chapter Five: What Genes Are, How They Work and Change
• Chapter Six: Some Practical Aspects of Plant Breeding
• Suggestions for Further Reading
• Glossary
• Additional Questions
• Index