Principles of Genetics BIOLOGY 310

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Principles of GeneticsBIOLOGY 310

• Professor Dr. Jennifer Dever
• www.usfca.edu/fac-staff/dever

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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

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I. What is Genetics?

• Overview of the history of genetics
• Aristotle, Hippocrates Pangenesis
• Spermists vs. Ovists
• Charles Darwin
• Gregor Mendel
• Thomas Hunt Morgan

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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

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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

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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)

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What do geneticists do?

• Utilize the scientific method
• Basic genetics research
• Applied genetics research

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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

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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

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B. Physical basis of heredity fundamental units

• DNA the genetic material
• Genome an organisms 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

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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.

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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

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Relationship between genes traits
Molecular level Cellular level Organismal
level Populational level