Paul Andersen explains how biogeochemical cycling is used to move nutrients from the environment into living material and back again. He explains the water cycle, the carbon cycle, the nitrogen cycle and the phosphorus cycle. He also explains the CHNOPS mnemonic device. He also explains why organisms need carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur.
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 the central dogma of biology. He explains how genes in the DNA are converted to mRNA through the process of transcription. He then explains how ribosomes use this message to convert the mRNA to a functioning protein. He also shows you how to decode a gene by converting the DNA to complementary mRNA and then to the specific amino acids in a protein.
Paul Andersen surveys organisms in the protists. He reviews the diversity found within the domain Eukarya and explains that the Kindgom Protista is simple a junk drawer for organisms that don't fit elsewhere.
Paul Andersen surveys the Kingdom Fungi. He starts with a brief description of the fungi phylogeny. He describes some of the major characteristics of fungi; heterotrophy, cell walls of chitin, hyphae, sessile. He describes the characteristics of five major phyla of fungi, ascomycota, basidiomycota, chytridiomycota, glomeromycota and zygomycota.
Paul surveys the Kingdom Plantae. He begins with a brief description of the phylogeny of land plants. He then describes the defining characteristics of plants, including cell walls, embryophytes, alternation of generation and photosynthesis. He briefly describes the sporophyte and the gametophyte. He finishes with brief discussion of plant evolution and includes major divisions, like bryophytes, ferns, gymnosperms, and angiosperms.
Paul Andersen briefly surveys members of the Domain Animalia. He begins with brief description of the phylogeny of animals. He then describes the characteristics of all animals, heterotrophy, multicellularity, motility and blastula. He describes eight invertebrates and vertebrates.
Paul Andersen describes the process of mitosis. He begins by discussing the importance of the cell cycle in development, regeneration, asexual reproduction and wound healing. He differentiates between haploid and diploid cells and describes the structure of the chromosome. He then moves through all the phases of mitosis; interphase, prophase, metaphase, anaphase, telophase and cytokinesis.
Paul Andersen explains the major plants structures. He starts with a brief discussion of monocot and dicot plants. He then describes the three main tissues in plants; dermal, ground and vascular. He also describes the plant cells within each of these tissues; epidermis, parenchyma, collenchyma, sclerencyma, xylem and phloem. He describes both primary and secondary growth in plants. He finishes the podcast with a discussion of double fertilization in plants.
Paul Andersen explains how nutrients and water are transported in plants. He begins with a brief discussion of what nutrients are required by plants and where they get them. He shows you dermal, vascular and ground tissue in monocot and dicot roots, stems and leaves. He then explains how water is pulled up a tree in xylem and how sugar is pushed in a plant through phloem.
Paul Andersen explains how plants use hormones to respond to their environment. The following hormones are detailed; auxin, cytokinins, gibberelins, abscisic acid and ethylene.
Paul Andersen reviews the concepts discovered by Gregor Mendel.
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 the process of meiosis produces variable gametes. He starts with a brief discussion of haploid and diploid cells. He compares and contrasts spermatogenesis and oogenesis. He explains how each person is different due to independent assortment, crossing over and random fertilization.
Paul Andersen shows you how to find stomata in a dicot and monocot leaf using finger nail polish and transparent tape. A microscope is required to actually see the stomata.
Paul Andersen explains the importance of blood types in blood transfusions. He starts with a brief discussion of blood antigens and antibodies. He describes how the ABO differs from the Rh blood type. He shows you how to solve simple genetic problems using Punnett squares. He then talks about the percentage distribution of the different types and the problems that may result during pregnancy.
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 steps you through eight types of animal behavior. He starts by defining ethology and explaining that behavior varies from innate to learned. He discusses each of the following with examples; instinct, fixed action pattern, imprinting, associative learning, trial and error learning, habituation, observational learning and insight.
Paul Andersen describes the process of ecological succession. During this process life reestablished itself after a disturbance. During primary success all of the material is removed including the soil. For example during a volcanic eruption all traces of life are removed. However during secondary success the soil remains intact. An example of secondary success is wildfires.
Paul Andersen explains the niche. He gives three different pronunciations and two different definitions. He then discusses the competitive exclusion principle and the idea that a niche cannot be shared by two species.
