1. Principles of Genetics BIOLOGY 310
Professor: Dr. Jennifer Dever

2. Intro Lecture outline:
What is Genetics?
Overview of the history of genetics
Principles to understanding heredity
Field of Genetics divided into three branches
What are the fundamental units of Genetics?
Elements of heredity
Physical basis of heredity = fundamental units
Levels of biological organization in genetics

3. I. What is Genetics? Overview of the history of genetics
Aristotle, Hippocrates – Pangenesis
Spermists vs. Ovists
Charles Darwin
Gregor Mendel
Thomas Hunt Morgan

4. Genetics – understanding heredity
Heredity = “a : the sum of the qualities and potentialities genetically derived from one's ancestors b : the transmission of such qualities from ancestor to descendant through the genes”
Geneticists investigate all forms of inherited variation, as well as the molecular basis underlying such characteristics

5. Principles to understanding heredity
All humans are united by a common set of traits, or observable characteristics
All of these characteristics are inherited
Variation exists among individuals
The environment can have an effect on characteristics

6. C. Field of Genetics: divided into 3 branches
Transmission genetics
Transmission of genes from generation to generation (Mendel)
Molecular genetics
Structure and function of genes at the molecular level (Watson & Crick; Avery)
Population genetics
Distribution and behavior of genes in populations (Hardy and Weinberg)

7. What do geneticists do? Utilize the scientific method
Basic genetics research
Applied genetics research

8. We are in the “Age of Genetics”
Alzheimer's Gene Identified
Dual Gene Therapy Suppresses Lung Cancer In Preclinical Test
Potential 'Off-Switch' For HIV Virus Found By Scientists
Genetic Mutation Alters Response To Heart Failure Drugs
Biotechnology
Bioinformatics
Genomics, Proteomics
Gene Therapy

9. II. What are the fundamental units of Genetics?
Elements of heredity:
Inherited traits are determined by the elements of heredity that are transmitted from parents to offspring in reproduction
Genes and chromosomes are the fundamental units of genetics

11. B. Physical basis of heredity = fundamental units
DNA = the genetic material
Genome = an organism’s basic complement of DNA
Haploid (n)
Diploid (2n)
Genes = segment of DNA that “codes” for a particular protein
Genes are expressed
Step one - transcription
Step two - translation

12. The molecular expression of genes within cells leads to an organisms’ outwardly visible traits.
The expression of a gene is a two step process.
One strand of DNA is transcribed into an RNA strand.
And the RNA strand is used to specify the sequence of amino acids within a polypeptide.
The polypeptide then functions within the cell, thereby influencing an organisms traits.

13. C. Levels of biological organization in genetics:
Genes are expressed at the molecular level
Proteins function at the cellular level
Traits are observed at the organismal level
The occurrence of a trait within a species is an observation at the population level

14. Relationship between genes & traits
Molecular level
Cellular level
Organismal level
Populational level