AGB 121: Principles Of Animal Genetics And
Population Genetics (2+1)
SYLLABUS
THEORY
History of Genetics, Chromosome number and types in livestock and poultry.
Mitosis, Meiosis and Gametogenesis. Overview of Mendelian principles; Modified
Mendelian inheritance: gene interaction; multiple alleles; lethal; sex-linked, sex
limited and sex influenced traits; linkage and crossing over, Mutation;
Chromosomal aberrations; Cytogenetics, Extra-chromosomal inheritance. Gene
concept - Classical and Molecular.
Population genetics: Genetic structure of population; Gene and genotypic
frequency; Hardy – Weinberg law and its application; Forces (e.g. Mutation,
migration, selection and drift) changing gene and genotypic frequencies.
Quantitative genetics: Nature and properties; Values and means, Components
of phenotypic and genotypic variance; Concept of genotype and environment
interaction, Resemblance between relatives; heritability, repeatability, genetic
and phenotypic correlations.
PRACTICAL
Demonstration of karyotype of Farm animal species; solving problems on inheritance of Mendelian
traits, Linkage and Crossing over. Calculation of gene and genotypic frequencies, Testing a
population for Hardy- Weinberg equilibrium; Calculation of effects of various forces that change
gene frequencies; Computation of population mean; Estimation of heritability, repeatability, Most
probable producing ability (MPPA), genetic and phenotypic correlations.
MODULE-1: INTRODUCTION
Learning objectives
After completing this module, the learner should be able to:
• understand the basic principles of inheritance.
• test and deepen their mastery of genetics by applying this knowledge in a variety
of problem-solving situations.
GENETICS
• Genetics
is the scientific study of the mechanism of heredity and variation.
Hereditary characteristics are determined by elementary units transmitted
between generations in uniform predictable fashion. Each unit called a gene
must satisfy at least two essential requirements:
, 1. that it is inherited in such fashion that each descendant has a
physical copy of the material and
2. that it provides information to its carriers in respect to structure,
function and other biological attributes.
• William Bateson introduced the term "genetics" (from the Greek word genno: to
give birth) to describe the study of inheritance and the science of variation in a
personal letter to Alan Sedgwick, dated April 18, 1905. The term "genetics" first
used publicly by Bateson at the Third International Conference on Plant
Hybridization in London in 1906.
• The terms gene, phenotype and genotype were coined by the Danish botanist
Wilhelm Johannsen and first used from 1909.
• Biological inheritance is the process by which a living organism produces a new
organism with many of the same traits as itself.
• Variation in inheritance is a fundamental concept in Darwin's theory of evolution.
• Drosophila melanogaster is the convenient model for the study of genetic
principles.
GENETICS APPLICATIONS
Some of the broad uses of knowledge of genetics are following:
• Genetics and eugenics: Genetics has suggested suitable possibilities for the
betterment of human race through certain fundamental laws of heredity.
• Genetics and agriculture: A significant advance in agricultural and animal
genetics and breeding improved the food production. The so called "green
revolution" and "white revolution" of to-day's India are the principal outcomes of
application of knowledge of genetics to the agriculture and animal breeding.
• Genetics and medical science: Genetics has significant applications in the various
human heritable diseases diagnosis and treatment.
• Genetics and legality: Genetics is helpful in solving various legal problems with
ease.
• Genetics in removing false concepts about heredity: Genetics has removed
various faulty beliefs and misunderstandings concerning the heredity which
commonly prevailed among the, different human societies.
MODULE-2: HISTORY OF GENETICS
Learning objectives
After completing this module, the learner should be able to:
• aware of the history and significant discoveries that can enrich the understanding
of the genetics present.
HISTORY OF GENETICS
,• The history of genetics is generally held to have started with the work of the
Augustinian monk, Gregor Johann Mendel who is called the "Father of
Genetics" for his study on the inheritance of traits in pea plants.
• The significance of Mendel's work was not recognized until their rediscovery by
the three scientists: Hugo de Vries (Holland), Carl Correns (Germany) and
Erich von Tschermak (Austria).
• The following outline is provided as an overview of and as topical guide to the
history of genetics:
o Pre - Mendelian Ideas on Heredity
o Mendel
o Post - Mendel
PRE - MENDELIAN IDEAS ON HEREDITY
• As early as the sixth century B.C., Greek philosophers had begun to search for
explanations of how and why the world and human beings came to be formed
and organized as they were.
• The work of Socrates (470-399 B.C.), Plato (429-347 B.C.), and Aristotle (384-
322 B.C.) established the foundations of Western philosophy.
• Pythagoras (570-495 B.C.) proposed the theory that animals are born from one
another by seeds and that seed is a drop from the brain which contains in itself
a warm vapour; and that when this is applied to the womb, it transmits virtue,
and moisture, and blood from the brain, from which flesh, and sinews, and
bones, and hair, and the whole body are produced. And from the vapour is
produced the soul, and also sensation.
o Pythagoras was one of the first to elaborate a theory of generation, the
biological production of offspring.
• According to Aristotle, the female parent contributed only unorganized matter to
the new individual while the male provided the form.
• Jan Swammerdam made observations using microscopes in the late 17 th century,
and interpreted their findings to develop the preformation theory, supposing
that an egg contained all the future generations of its kind as preformed
miniatures.
• William Harvey (1578-1657), in his publication the generation of animals (1651)
argue that all living beings arose from eggs.
• Dutch microscopist Antonie van Leeuwenhoek (1932-1723) was one of the first to
observe spermatozoa.He reasoned that the movement of spermatozoa was
evidence of animal life, which presumed a complex structure and, for human
sperm, a soul.
• In 1694, Nicolas Hartsoeker produced an image of tiny men inside the sperm,
which he called " animalcule" or "homunculus ".
• Carl Linnaeus (1707-1778) Swedish naturalist and explorer was the first to frame
principles for defining natural genera and species of organisms and to create a
uniform system for naming them (binomial nomenclature).
• Lamarck (1744–1829) pioneer French biologist who is best known for his idea
that acquired characters are inheritable, an idea also known as
, Lamarckism, and which is controverted by modern genetics and
evolutionary theory.
• Lamarckism or Lamarckian evolution refers to the once widely accepted idea that
an organism can pass on characteristics that it acquired during its lifetime to
its offspring (also known as based on heritability of acquired characteristics or
"soft inheritance"). Lamarck stressed two main themes in his biological work.
o The first was that the environment gives rise to changes in animals.
o The second principle was that life was structured in an orderly manner
and that many different parts of all bodies make it possible for the
organic movements of animals. It proposed that individual efforts
during the lifetime of the organisms were the main mechanism driving
species to adaptation, as they supposedly would acquire adaptive
changes and pass them on to offspring.
• Charles Robert Darwin (1809-1882) English naturalist and founder of modern
evolutionary theory proposed and provided scientific evidence that all species
of life have evolved over time from common ancestors through the process
which he called Natural Selection.
o Darwin found that those organisms more suited to their environment
were more likely to survive. This resulted in the well known phrase
survival of the fittest.
o Pangenesis was Charles Darwin's hypothetical mechanism for heredity.
Gemmules, also called plastitudes or pangenes, were assumed to be
shed by the organs of the body and carried in the bloodstream to the
reproductive organs where they accumulated in the germ cells or
gametes.
o They thus provided a possible mechanism for the inheritance of
acquired characteristics, as proposed by Jean-Baptiste Lamarck.
• Regnier De Graaf is famous for having discovered the ovarian follicle (which is
named Graafian follicle in his honour).
• A new way of thinking about heredity, fertilization, and development was made
possible by the establishment of the Cell Theory in the 1830s.
• The establishment of cell theory is generally attributed to Matthias Jacob
Schleiden (1804-1881) and Theodor Schwann (1810-1882), who recognized the
importance of Robert Brown's (1773-1858) discover of the cell nucleus.
• Further investigations during the last quarter of the nineteenth century provided
many insights into the role played by the nucleus during cell division, and the
recognition of fundamental cytological phenomena such as mitosis,
maturation, and fertilization and important cellular organelles, such as
mitochondria, chloroplasts, and the Golgi apparatus.
• Cytological studies led to the discoveries that linked cytology to inheritance and
development.
• Based on these studies, Friedrich Leopold August Weismann (1834-1914)
proposed the theory of the continuity of the germplasm and predicted the
reduction division of the chromosomes during the formation of the germ cells.
He advocated the germ plasm theory, according to which (in a multicellular
organism) inheritance only takes place by means of the germ cells -the gametes
such as egg cells and sperm cells. -
Population Genetics (2+1)
SYLLABUS
THEORY
History of Genetics, Chromosome number and types in livestock and poultry.
Mitosis, Meiosis and Gametogenesis. Overview of Mendelian principles; Modified
Mendelian inheritance: gene interaction; multiple alleles; lethal; sex-linked, sex
limited and sex influenced traits; linkage and crossing over, Mutation;
Chromosomal aberrations; Cytogenetics, Extra-chromosomal inheritance. Gene
concept - Classical and Molecular.
Population genetics: Genetic structure of population; Gene and genotypic
frequency; Hardy – Weinberg law and its application; Forces (e.g. Mutation,
migration, selection and drift) changing gene and genotypic frequencies.
Quantitative genetics: Nature and properties; Values and means, Components
of phenotypic and genotypic variance; Concept of genotype and environment
interaction, Resemblance between relatives; heritability, repeatability, genetic
and phenotypic correlations.
PRACTICAL
Demonstration of karyotype of Farm animal species; solving problems on inheritance of Mendelian
traits, Linkage and Crossing over. Calculation of gene and genotypic frequencies, Testing a
population for Hardy- Weinberg equilibrium; Calculation of effects of various forces that change
gene frequencies; Computation of population mean; Estimation of heritability, repeatability, Most
probable producing ability (MPPA), genetic and phenotypic correlations.
MODULE-1: INTRODUCTION
Learning objectives
After completing this module, the learner should be able to:
• understand the basic principles of inheritance.
• test and deepen their mastery of genetics by applying this knowledge in a variety
of problem-solving situations.
GENETICS
• Genetics
is the scientific study of the mechanism of heredity and variation.
Hereditary characteristics are determined by elementary units transmitted
between generations in uniform predictable fashion. Each unit called a gene
must satisfy at least two essential requirements:
, 1. that it is inherited in such fashion that each descendant has a
physical copy of the material and
2. that it provides information to its carriers in respect to structure,
function and other biological attributes.
• William Bateson introduced the term "genetics" (from the Greek word genno: to
give birth) to describe the study of inheritance and the science of variation in a
personal letter to Alan Sedgwick, dated April 18, 1905. The term "genetics" first
used publicly by Bateson at the Third International Conference on Plant
Hybridization in London in 1906.
• The terms gene, phenotype and genotype were coined by the Danish botanist
Wilhelm Johannsen and first used from 1909.
• Biological inheritance is the process by which a living organism produces a new
organism with many of the same traits as itself.
• Variation in inheritance is a fundamental concept in Darwin's theory of evolution.
• Drosophila melanogaster is the convenient model for the study of genetic
principles.
GENETICS APPLICATIONS
Some of the broad uses of knowledge of genetics are following:
• Genetics and eugenics: Genetics has suggested suitable possibilities for the
betterment of human race through certain fundamental laws of heredity.
• Genetics and agriculture: A significant advance in agricultural and animal
genetics and breeding improved the food production. The so called "green
revolution" and "white revolution" of to-day's India are the principal outcomes of
application of knowledge of genetics to the agriculture and animal breeding.
• Genetics and medical science: Genetics has significant applications in the various
human heritable diseases diagnosis and treatment.
• Genetics and legality: Genetics is helpful in solving various legal problems with
ease.
• Genetics in removing false concepts about heredity: Genetics has removed
various faulty beliefs and misunderstandings concerning the heredity which
commonly prevailed among the, different human societies.
MODULE-2: HISTORY OF GENETICS
Learning objectives
After completing this module, the learner should be able to:
• aware of the history and significant discoveries that can enrich the understanding
of the genetics present.
HISTORY OF GENETICS
,• The history of genetics is generally held to have started with the work of the
Augustinian monk, Gregor Johann Mendel who is called the "Father of
Genetics" for his study on the inheritance of traits in pea plants.
• The significance of Mendel's work was not recognized until their rediscovery by
the three scientists: Hugo de Vries (Holland), Carl Correns (Germany) and
Erich von Tschermak (Austria).
• The following outline is provided as an overview of and as topical guide to the
history of genetics:
o Pre - Mendelian Ideas on Heredity
o Mendel
o Post - Mendel
PRE - MENDELIAN IDEAS ON HEREDITY
• As early as the sixth century B.C., Greek philosophers had begun to search for
explanations of how and why the world and human beings came to be formed
and organized as they were.
• The work of Socrates (470-399 B.C.), Plato (429-347 B.C.), and Aristotle (384-
322 B.C.) established the foundations of Western philosophy.
• Pythagoras (570-495 B.C.) proposed the theory that animals are born from one
another by seeds and that seed is a drop from the brain which contains in itself
a warm vapour; and that when this is applied to the womb, it transmits virtue,
and moisture, and blood from the brain, from which flesh, and sinews, and
bones, and hair, and the whole body are produced. And from the vapour is
produced the soul, and also sensation.
o Pythagoras was one of the first to elaborate a theory of generation, the
biological production of offspring.
• According to Aristotle, the female parent contributed only unorganized matter to
the new individual while the male provided the form.
• Jan Swammerdam made observations using microscopes in the late 17 th century,
and interpreted their findings to develop the preformation theory, supposing
that an egg contained all the future generations of its kind as preformed
miniatures.
• William Harvey (1578-1657), in his publication the generation of animals (1651)
argue that all living beings arose from eggs.
• Dutch microscopist Antonie van Leeuwenhoek (1932-1723) was one of the first to
observe spermatozoa.He reasoned that the movement of spermatozoa was
evidence of animal life, which presumed a complex structure and, for human
sperm, a soul.
• In 1694, Nicolas Hartsoeker produced an image of tiny men inside the sperm,
which he called " animalcule" or "homunculus ".
• Carl Linnaeus (1707-1778) Swedish naturalist and explorer was the first to frame
principles for defining natural genera and species of organisms and to create a
uniform system for naming them (binomial nomenclature).
• Lamarck (1744–1829) pioneer French biologist who is best known for his idea
that acquired characters are inheritable, an idea also known as
, Lamarckism, and which is controverted by modern genetics and
evolutionary theory.
• Lamarckism or Lamarckian evolution refers to the once widely accepted idea that
an organism can pass on characteristics that it acquired during its lifetime to
its offspring (also known as based on heritability of acquired characteristics or
"soft inheritance"). Lamarck stressed two main themes in his biological work.
o The first was that the environment gives rise to changes in animals.
o The second principle was that life was structured in an orderly manner
and that many different parts of all bodies make it possible for the
organic movements of animals. It proposed that individual efforts
during the lifetime of the organisms were the main mechanism driving
species to adaptation, as they supposedly would acquire adaptive
changes and pass them on to offspring.
• Charles Robert Darwin (1809-1882) English naturalist and founder of modern
evolutionary theory proposed and provided scientific evidence that all species
of life have evolved over time from common ancestors through the process
which he called Natural Selection.
o Darwin found that those organisms more suited to their environment
were more likely to survive. This resulted in the well known phrase
survival of the fittest.
o Pangenesis was Charles Darwin's hypothetical mechanism for heredity.
Gemmules, also called plastitudes or pangenes, were assumed to be
shed by the organs of the body and carried in the bloodstream to the
reproductive organs where they accumulated in the germ cells or
gametes.
o They thus provided a possible mechanism for the inheritance of
acquired characteristics, as proposed by Jean-Baptiste Lamarck.
• Regnier De Graaf is famous for having discovered the ovarian follicle (which is
named Graafian follicle in his honour).
• A new way of thinking about heredity, fertilization, and development was made
possible by the establishment of the Cell Theory in the 1830s.
• The establishment of cell theory is generally attributed to Matthias Jacob
Schleiden (1804-1881) and Theodor Schwann (1810-1882), who recognized the
importance of Robert Brown's (1773-1858) discover of the cell nucleus.
• Further investigations during the last quarter of the nineteenth century provided
many insights into the role played by the nucleus during cell division, and the
recognition of fundamental cytological phenomena such as mitosis,
maturation, and fertilization and important cellular organelles, such as
mitochondria, chloroplasts, and the Golgi apparatus.
• Cytological studies led to the discoveries that linked cytology to inheritance and
development.
• Based on these studies, Friedrich Leopold August Weismann (1834-1914)
proposed the theory of the continuity of the germplasm and predicted the
reduction division of the chromosomes during the formation of the germ cells.
He advocated the germ plasm theory, according to which (in a multicellular
organism) inheritance only takes place by means of the germ cells -the gametes
such as egg cells and sperm cells. -
