Paul Andersen describes mechanisms that increase the genetic variation within a population. He begins by discussing how horizontal transfer can move genetic material between bacteria. Transformation, transduction, and conjugation in bacteria are all included. He also explains how crossing over, random assortment, and random fertilization can maintain genetic variation in eukaryotes. He also explains how inbreeding can decrease the fitness of an individual.

Paul Andersen explains how changes in the genotype of an individual can affect the phenotype. He begins with genotype:phenotype::letters:story analogy. He explains how mutations can be neutral, beneficial or harmful. He also explains how mistakes in the cell cycle can lead to disorder, sterility or new species.

 

Paul Andersen explains how signal transmission is used to alter both cellular function and gene expression. He uses the example of epinephrine release in humans and how it is used in the fight or flight response. Epinephrine causes liver cells to release glucose that is normally stored as glycogen when they receive the signal of epinephrine. They are also able to create different enzymes when receiving this signal. The signal transduction pathway and the importance of CyclicAMP is included.

Paul Andersen explains how genes are regulated in both prokaryotes and eukaryotes. He begins with a description of the lac and trp operon and how they are used by bacteria in both positive and negative response. He also explains the importance of transcription factors in eukaryotic gene expression.

Paul Andersen explains important concepts that can not be explained by simple Mendelian genetics. He begins with a discussion of polygenic inheritance and uses a simulation on height to show how a bell shape curve of phenotypes is produced. He then discusses the importance of linked genes and those that are found on the sex chromosome. A simple punnett square showing the inheritance of the color blind gene is included.

Paul Andersen explains simple Mendelian genetics. He begins with a brief introduction of Gregor Mendel and his laws of segregation and independent assortment. He then presents a number of simple genetics problems along with their answers. He also explains how advances in genetic knowledge may lead to ethical and privacy concerns.

 

Paul Andersen continues his description of DNA and RNA. He begins with the structure of DNA and RNA and moves into the process of DNA Replication. He also describes the central dogma of biology explaining how DNA is transcribed to mRNA and is finally translated into proteins. He also introduces genetic engineering and explains how transformation is used to create insulin.

Paul Andersen introduces the nucleic acids of life; RNA and DNA. He details the history of DNA from Griffith, to Avery, to Hershey and finally to Watson and Crick. He also details the difference between prokaryotic and eukaryotic chromosomes.

Regulation of Timing and Coordination in Development - Paul Andersen explains how genes control the timing and coordination of embryo development. Seed germination initiates the discussion of cell differentiation. The SRY gene and genetic transplantation shows the importance of embryonic discussion. Cell deat is also an important part of development that is regulated by microRNA. HOX genes (a form of homeotic genes) is also discussed.