INTRODUCTION TO THE SCIENCE OF GENETICS

Vitug, Jan Thea Marie O.AAPD 2E

HISTORY ON THE DEVELOPMENT OF

GENETICS AS A SCIENCE

• GREGOR MENDEL- Father of Modern Genetics- experimented on the pea plant in 1866.

• CHARLES DARWIN- Father of Evolution- Theory of Natural Selection; Origin of Species

• ARISTOTLE–PANGENESIS

There is a transmission of trait from one generation to another.

There is a hereditary factor.

*PREFORMATIONISM- “HOMONCULUS” in a

sperm and egg cell

• SUTTON- associated the behavior

of chromosomes to genes

• AVERY, MACLEOD & MACCARTHY-genetic material is DNA

• MEISCHER -gave the idea to Avery, MacLeod And MacCarthy that there is a weak

acid

• ROSALIND FRANKLIN -able to give the idea of the structure of DNA using X-Ray

• WATSON AND CRICK-gave the double structure of

DNA which is helix

• CORRENS, DE VRIES, TSCHERMAK (1900)

-duplicated the study of Mendel

BRANCHES / SCOPE / FIELDS

• CYTOGENETICS-physical basis of heredity

• MOLECULAR GENETICS-chemical basis of heredity-sub-branches:

GENOMICS – study of genes – most advanced

PROTEOMICS – study of proteins

• CLASSICAL GENETICS- tools and techniques on genetics- way how traits are transmitted

• POPULATION GENETICS

- transmission of genes in a population

- transmission of traits in large group of individuals through the passage of time

• BEHAVIORAL-influence of varying genetics on

animal behavior, effects of human disorders as well as its causes

METHODS OF GENETIC STUDY

• PEDIGREE ANALYSIS- uses pedigree to

study the transmission of traits in a family

*PEDIGREE – pictorial representation od the members of the family

• KARYOTYPING- detect chromosomal abnormalities- uses karyotype or karyogram

*KARYOTYPE – pictorial representation of chromosomes

• PLANNED EXPERIMENTAL BREEDING

- uses Punnet Square

*PUNNET SQUARE - diagram that is used to predict an outcome of a particular cross or breeding experiment

• TWIN STUDY- Fraternal (Dizygotic twin)

2 zygote = 2 fertilized egg - Identical (Monozygotic twin)

1 zygote = 1 fertilized egg

*POINT OF STUDY:- Concordance Twin

Both posses a trait or both does not posses a trait

One posses a trait and the other does not

• STATISTICAL ANALYSIS- for data that are recorded- large number- used in Population Genetics

APPLICATIONS OF GENETICS

• LEGAL APPLICATION/ FORENSIC- for solving crimes

ex. Fingerprints

• AGRICULTURE- genetically modified plants and

animals

• FIELD OF MEDICINE/ MEDICAL APPLICATION- detecting diseases that are hereditary- gene therapy

• GENETIC COUNSELING- to give counsel to prospective parents

• INDUSTRY- drugs

ex. Insulin

• GENETIC ENGINEERING- modifying a particular plant or animal

THE END