Paul Andersen describes the major mutations found in the living world. He starts with an analogy comparing the information in DNA with the information in a recipe. Changes in the DNA can result in changes to the protein, like changes in the recipe can result in changes in the food. He describes the three major point mutations; substitutions, deletions and insertions. He also describes several chromosomal mutations.
Paul Andersen explains how the Meselson-Stahl experiment was used to prove that DNA copied itself through a semi-conservative process. They grew E. coli in a medium containing heavy nitrogen (N-15). They then added the E. coli to a medium containing regular nitrogen (N-14) and observed it over several generation.
Paul Andersen describes the process of DNA fingerprinting and DNA profiling. He explains how variability in STRs can be used to identify individuals. He explains the importance of DNA fingerprinting in forensics and paternity cases.
Paul Andersen explains how DNA replication ensures that each cell formed during the cell cycle has an exact copy of the DNA. He describes the Meselson-Stahl experiment and how it showed that DNA copies itself through a semi-conservative process. He then explains how multiple enzymes, like DNA polymerase, helicase, primase, ligase, and single strand binding proteins copy DNA. He also differentiates between the leading and the lagging strand. He explains how DNA is anti-parallel in nature and how eukaryotic cells have multiple origins of replication.
Paul Andersen explains aspects of genetics that were not covered by Gregor Mendel. He begins with the following topics; incomplete dominance, codominance, epistasis, multiple alleles, and multiple genes. He then explains how linked genes were discovered by Thomas Hunt Morgan and Alfred Sturtevant. He also discusses sex-linked traits.
Paul Andersen explains how X inactivation works in mammals. This process was first described by Mary Lyon. Each cell in a female will have on activated and one inactivated X chromosome. This explains why almost all calico cats are female.
Paul Andersen explains the two major portions of the molecular biology lab in AP Biology. He starts by discussing the process of transformation. He explains how you can use the pGLO plasmid to produce glowing E. coli bacteria. He then describes how you can use restriction enzymes and the process of gel electrophoresis to cut and separate DNA.
Mr. Andersen explains the Central Dogma of biology. He shows how DNA is transcribed to form mRNA and how mRNA is translated into a protein.
