Principle of genetics

1. Lesson 1.1
Fundamental Concepts of Genetics

2. LEARNING OUTCOMES
• Discuss genetics as a body of knowledge and a process;
• Trace the origin and historical perspective of genetics;
• Identify the different sciences related to the study of genetics;
• Enumerate tools being used in studying genetics;
• Reflect on the importance of genetics on our lives.

3. • The world of genetics- evolving from evolution focuses to what
is now known as the heredity and variation. It touches related
disciplines such as biology, cytology, histology, embryology,
etc. and the connections that linked between them. Before the
flourishing time of Genetics, some scientist underwent series
and careful studies towards its concepts. Some of them that
makes the world of Genetics beautiful is Gregor Mendel with
his experiment on the garden peas.

4. • Genetics is simply defined as a science that deals on the
study of heredity and variation. Heredity deals on the
natural process of passing of traits from parents to
offspring. Variation is the divergence in the structural or
functional characteristics of an organism.
• Genes are bits of biochemical instructions. The complete
set of genetic instructions for any organism is called a
genome. It is either RNA or DNA. And coding system for
genomic information very similar among organisms.

5. • There are three main divisions of genetics
namely transmission, molecular, and
population genetics.
• Transmission genetics focuses on how the
traits are being passed from one parent to the
offspring.
• Molecular genetics deals on the actions of the
genetic molecule and the processes they
exhibit.

6. • Population genetics focuses on the characteristics that a population
possess. These three divisions are inseparable with the other. Model
genetic organisms are organisms with characteristics that make them
useful for genetic analysis. Six have been the most intensively studied
genetically. These are Drosophila melanogaster, Escherichia coli,
Caenorhabditis elegans, Arabidopsis thaliana, Mus musculus,
Saccharomyces cerevisiae.
• There are common characteristics of model organisms; it must have short
generation time, production of numerous progeny, have the ability to
carry out controlled genetic crosses, has the ability to be reared in the
laboratory environment, has the availability of genetic variants, and have
an accumulated body of knowledge about their genetic system.

7. Drosophila
melanogaster
Escherichia
coli
Caenorhabditis
elegans
Arabidopsis
Mus
musculus

8. HISTORICAL PERSPECTIVE
Early views of heredity concepts
• Ancient people breed domestics animals and crops without knowing
that they already know that is genetics already. For example; they apply
selective breeding techniques in producing a new variety of corn and
wheat that had never in the rainforest.
• Late the 4th century BC, Aristotle suggested that acquired characteristics
such as a scar that is dominant during childhood could be passed to the
offspring. The Pangenesis theory arises from that concept. It is believed
that, according to the theory, the particles inside the body-called
gemmules- which resides in the organ and limbs and then it moves to
the reproductive organs so then transferred to the child carrying that
traits.

9. HISTORICAL PERSPECTIVE
Year after, Jean Baptiste Lamarck formalized the theory of “use and dis-
use” or the theory of acquired characteristics. He proposed that, when
there is a change in the environment that organism will adopt. Thus,
acquiring the required characteristics to be passed.

10. HISTORICAL PERSPECTIVE
Mendel and Darwin’s Influences traced
• Before Mendel’s work was taken into account, Charles Darwin pinned down
the theory of evolution. According to this theory, that certain organism
evolves from the same ancestor but due to time it drastically changes its
structure and characteristics. When he published the book On the Origin of
Species by means of Natural Selection, scientist reinvent themselves and
started to consider why and how organism changes. on the other hand,
• Gregor Mendel was known as the father of genetics for his detailed
experiments about the garden peas. He uses the seed shape and flower
color just to mention a few about his experiments.

11. HISTORICAL PERSPECTIVE
Science of Genetics emerge
• Several decades, William Bateson-coined the term genetics in 1905.
While in 1909, the term gene and genome were coined by Wilhelm
Johannsen. Development of the said discipline immediately arises.
Thomas Hunt Morgan research on the characteristics of the white-eyed
fly, Drosophila melanogaster, about their eye color. Then Alfred
Sturtevant proposed the concepts of crossing over. Later on, Barbara
McClintock developed the ideas on the jumping genes.

12. HISTORICAL PERSPECTIVE
Outbreak of DNA studies
• Frederick Griffith discovered the transforming factor with his mice
experiment. After a series of time, Rosalind Franklin and Maurice
Wilkins use X-ray diffraction to have a clear image of the DNA.
• But the 3-D model of the DNA was solved by James Watson and
Francis Crick. On the other hand, Har Gobind Khorana help unravel the
dictionary of codons. 12 years after that, the structure of DNA was
deduced and the problem was solved.

13. HISTORICAL PERSPECTIVE
DNA manipulation
• Between 1960s and 1970s after the breakthrough of the discipline, many scientists try to
manipulate the DNA. Werner Arber deals on the restriction of enzymes that could cut
DNA. In the next decade, Hamilton Smith determined the specific nucleotide sequence.
While Herb Boyer, focuses on the study of recombinant DNA.
• Consequently, Stanley Cohen- coined and idealized the concepts of cloning. While
Kary Mullis developed the PCR-polymerase Chain Reaction in order to make many
copies of DNA. Advances continues to 1980, when Frederick Sanger developed DNA
sequencing techniques known as dideoxy nucleotides. Today, all are part of the human
genome project.

14. RELATED DISCIPLINES OF GENETICS
• Although Genetics is a branch of biology, it has many related disciplines to
deal with. We all know that biology is the study of life while genetics is the
study of heredity and variation. In a broad sense, genetics touches other
field of sciences such as cytology, histology, organology, embryology, cell
biology, and evolution. Cytology focuses on the study of cells. Histology
focuses on the study of tissues. Organology focuses on the study of organs.
Embryology focuses on the study of embryonic development as in cell
biology. Evolution focuses on the study of genetic changes.

15. IMPORTANCE OF GENETICS
• In the field of agriculture, BT corn plantation is being practiced due to its
various benefits and productive yield. Some rice, corn, wheat, apple, and other
plants have been genetically modified in order to withstand the attack of pest.
In the population, certain DNA tracing and fingerprinting are used to convict
criminals with the traces of hair, nails, skin tissues that could be found in the
crime scene.

16. TOOLS USED TO STUDY GENETICS
• Some of the tools geneticist used are DNA fingerprinting, altering
bacteria, gene therapy, and genetically engineered vaccine. Each of
these has specific fields and importance to deal with. The Human
Genome Project help maintain the balance between the forces
whether what genetics could do in the near future.