1. Unit I
Introduction to
the Science of Genetics
Agripa, Vanessa Abigail M.
Seda, Sarah Jane P.

2. A brief History
Of Genetics

3. A brief History of Genetics
• The genetics started with the work
of the Augustinian friar Gregor
Johann Mendel. His work on pea
plants, published in 1866, described
what came to be known
as Mendelian Inheritance.
• 1900 marked the "rediscovery of
Mendel" by Hugo de Vries, Carl
Correns and Erich von Tschermak,
and by 1915 the basic principles of
Mendelian genetics had been
applied to a wide variety of
organisms—most notably the fruit fly
Drosophila melanogaster.

4. • Led by Thomas Hunt Morgan and his
fellow "drosophilists", geneticists
developed theMendelian, which was
widely accepted by 1925. Alongside
experimental work, mathematicians
developed the statistical framework
of population genetics, bringing
genetic explanations into the study
of evolution.
• With the basic patterns of genetic
inheritance established, many
biologists turned to investigations of
the physical nature of the gene. In the
1940s and early 1950s, experiments
pointed to DNA as the portion of
chromosomes (and perhaps other
nucleoproteins) that held genes.

5. Genetics Today
• Genetics Today objectives are oriented to the following aspects:
• To provide the required genetic information associated with human
disease
• To integrate related disciplines such as biology, chemistry, molecular
biology and epidemiology with modern genetics, in particular with
genomics and epigenomics
• To promote clinical application of innovative new genetic
approaches
• To offer an interdisciplinary forum for the discussion of new
developments based on genetics knowledge
• To apply genetics as an important tool for the development of new
therapeutic alternatives for the treatment of human disease
conditions
• To improve the knowledge and practice of medical genetics
Genetics Today will publish original articles, short communications,
comments, letters to the Editor, and review articles upon invitation.

6. Branches of Genetics

7. Branches of Genetics
• Cytogenetics
The heredity units or genes are formed of
DNA. These are integral part of
chromosomes. The chromosomes are
contained in the nucleus. The nuclei of germ
cells are the only bridge between successive
generations. The study of genes in the cell is
called Cytogenetics.
• Biochemical Genetics
The chemistry of chromosomes, genes and
nucleic acids and the chemistry of various
processes related to them are studied with
the help biochemistry. The branches of
science which is considered with the
biochemical study of genetic material are
named as 'Biochemical Genetics.'

8. Branches of Genetics
• Physiological Genetics
Genetics helps in explaining
some very important
physiological characteristics
like blood groups, Rh factor,
alkaptoneuria, sex
differentiation and sex
determination. Some
physiological abnormalities like
sickle cell anemia etc can be
explained with the aid of
genetic knowledge.

9. Branches of Genetics
• Clinical Genetics
Genetics has also helping in finding
out the root cause of certain diseases
like hemophilia, diabetes etc. All
these diseases are caused on
account of defective genotype.
Moreover serology and blood
transfusion are two most important
fields, where genetics has directly
assisted physiology and helped in
saving life.
• Radiation Genetics
The study of effects of radiations on
genes and the changes in their
expression is being studied widely in
the field of Radiation Genetics

10. Importance of Genetics
• Genetic knowledge allowed vast improvement in
productivity of domesticated plant species used for food
(rice, wheat, corn). Genetic knowledge has also been a
key component of the revolution in health and medical
care in this century.
• Bioengineering - directly altering the genetic material
of an organism
Developed by: Herbert W. Boyer and Stanley N. Cohen
Allows segments of DNA to be moved to different
locations or removed from the DNA molecule, thus
acquiring new genes and new genetic traits
• Health - About 3-5% of the world population (200 million
people) are estimated to be afflicted by serious genetic
disease
Genetic knowledge has already allowed for treatment
and genetic counseling (to prevent recurrence) of
Down’s Syndrome and PKU
Production of antibiotic resistant organisms
Bioengineering offers the hope of creating more
effective antibiotics
Human Growth Hormone-treatment for dwarfism

11. Genetic Engineering
• Alteration of an
individual's genotype with the aim of
choosing the phenotype of a
newborn or changing the existing
phenotype of a child or adult. It holds
the promise of curing genetic
diseases like cystic fibrosis, and
increasing the immunity of people to
viruses. It is speculated that genetic
engineering could be used to
change physical appearance,
metabolism, and even improve
mental faculties like memory and
intelligence, although for now these
uses seem to be of lower priority to
researchers and are therefore
limited to science fiction.

12. Application of Genetics
• Biotechnology has commercial potential in
medicine, agriculture, chemicals and the
environment. Once concerned only with the
production of genetically engineered proteins,
the commercial biotechnology industry now
includes the discovery and development of
synthetic small-molecule chemical drugs (called
biochemotechnology), gene therapy, cell
therapy, carbohydrate engineering, DNA-coated
silicon chips, and more.
• The creation of transgenic animals and plants
has generated huge markets for many countries.
Genetically engineered fish and trees are
revolutionizing the aquaculture and lumber
industries. Transgenic crops currently on the
market include soybeans, corn, cotton and
canola. In 1999, almost half the area planted to
transgenic varieties was almost half of the United
States soybean crop and about 25 per cent of
the United States corn crop. Most of the
transgenic crop varieties are either herbicide

13. • Another area of the foods market
where genetics has tremendous
potential is nutraceuticals--foods
whose nutritional value is enhanced.
The current nutraceutical market of
$17 billion is expected to grow in
five years to be worth $250 billion
annually. While nutraceutical are
popular with consumers, so-called
genetically modified foods are as yet
controversial and the health risks
associated with their consumption,
while innocuous based on available
evidence, remains a concern.

14. • While genetically engineered foods have yet to be
widely embraced, biotechnology in the medical
industry has exploded. Genetics has made it possible
to understand how hereditary diseases and other
familial traits are transmitted between generations.
This has provided the opportunity to advise parents as
to the likelihood of future offspring developing or
transmitting certain conditions. Examination of
embryonic fluid has made it possible to forecast
whether an embryo will suffer from certain hereditary
conditions at birth. Other medical applications
dominate the biotechnology industry. In 1997, protein
drugs of regular and genetically engineered natures
had worldwide sales totaling nearly $24 billion,
involving a bulk production of nearly one billion grams.
The recombinant share comprised only 0.5 per cent of
this bulk production. However, its share of dollars
sales, about $12 billion, comprised about 50 per cent.
Elsewhere, the industry is already developing
genome-based drugs or gene therapy strategies
against cancer, Alzheimer's disease, Parkinson's
disease, heart disease, diabetes, multiple sclerosis
and AIDS.

15. References
• http://www.bookrags.com/research/industrial-applications-of-genetics-wog/
• http://www.nlm.nih.gov/medlineplus/
• http://topnews.net.nz/content/212835-stem-cell-therapy-might-be-useful-treating-many-serious-diseases
• http://www.citrusextracts.com/nutra.htm
• http://www.biology-online.org/biology-forum/about827.html
• http://www.butbn.cas.cz/ccala/index.php?page=sr&bol4=b4o&bol5=b5lo&locality=Russia
• http://www.pachs.net/dialogues-with-darwin/item/100
• http://www.biocourseware.com/iphone/ghistory/
• http://www.dartmouth.edu/~bio70/
• http://psych.colorado.edu/~carey/hgss2/pdfiles/Ch%2001%20History%20of%20Genetics.pdf
• http://naturalselection.0catch.com/Files/gregormendel.html
• ^ July 20 is his birthday; often mentioned is July 22, the date of his baptism. Biography of Mendel at the Mendel Museum
• ^ "Gregor Mendel". Encyclopædia Britannica. Retrieved 21 July 2011.
• ^ a b c Bowler, Peter J. (2003). Evolution: the history of an idea. Berkeley: University of California Press. ISBN 0-520-23693-9.
• ^ Gregor Mendel, Alain F. Corcos, Floyd V. Monaghan, Maria C. Weber "Gregor Mendel's Experiments on Plant Hybrids: A Guided
Study", Rutgers University Press, 1993.
• ^ a b c "The Mathematics of Inheritance". Online museum exhibition. The Masaryk University Mendel Museum. Retrieved Jan. 20, 2010.
• ^ a b c "Online Museum Exhibition". The Masaryk University Mendel Museum. Retrieved Jan. 20, 2010.
• ^ "The Enigma of Generation and the Rise of the Cell". The Masaryk University Mendel Museum. Retrieved Jan. 20, 2010.
• ^ "Mendel's Garden|[". The Masaryk University Mendel Museum. Retrieved Jan 20, 2010.
• ^ Randy Moore (May 2001 vol=27). "The "Rediscovery" of Mendel's Work". Bioscene.