Humans have been aware of genetics, via selective breeding, for over 10,000 years. Our current understanding of human genetics was built upon experimental knowledge and discoveries about DNA.

1.1 Introduction to Genetics: An amateur botanist Gregor Mendel published an explanation of hereditary transmission in plants in 1866. His work was independently
rediscovered in 1900 by three botanists: Carl Correns in Germany, Hugo de Vries in Holland, and Erich von Tschermak in Austria. This is how modern genetics began.

● Genetics Now and Then
● The First Century of Modern Genetics
● Frederic Griffith: Bacterial Transformation
● Avery, McCarty, and MacLeod: Identifying the Transforming Principle
● The Hershey-Chase Experiments

1.2 The Molecular Basis of Heredity Variation and Evolution: DNA is the genetic code by which information is passed from parent to offspring. Strings of code for genes make up chromosomes as strings of yarn make up a sweater. DNA and RNA have distinct differences in their composition that allow for the genetic processes that drive life. DNA is a working molecule; it must be replicated when a cell is ready to divide, and it must be “read” to produce the molecules, such as proteins, to carry out the functions of the cell.

● DNA Structure, Genes and Chromosomes, RNA Structure
● DNA Cell Arrangement and Genomic DNA
● Cell Division and DNA Replication
● The Central Dogma – Creating Proteins From DNA
● Transcription: From DNA to mRNA
● Translation: Protein Synthesis
● The Genetic Code and Translation
● Forces of Evolution: Mutations, Natural Selection, Genetic Drift,
Migration (Gene Flow), Nonrandom Mating
● Genetic Variance
● Determining Evolutionary Relationships
● Building a Phylogenetic Tree Using Multiple Characteristics
● Building a Phylogenetic Tree Using Molecular Data

Learn how the properties of organisms pass from parents to offspring in a way that sustains evolution by natural selection. Transmission genetics deals with the manner in which genetic differences among individuals are passed from generation to generation. How does a cell go about dividing? Learn about the important processes of mitosis and meiosis.

2.1 Transmission Genetics: How do rules for adding and multiplying genetic equations work? Probability is a mathematical tool used to study randomness. When calculating a probability, there are two rules to consider when determining if two events are independent or dependent and if they are mutually exclusive or not. Many types of probability problems have two outcomes or can be reduced to two: success and failure.

● Probability Rules: Addition and Product Rules
● Conditional Probability and Genetics
● Binomial Distribution
● Independent Events and the Multiplicative Rule of Probability
● Mendel’s Crosses – Studying Inheritance
● Basics of Heredity – Dominant and Recessive Traits
● Phenotypes and Genotypes
● Mendel’s Law of Segregation
● Mendel’s Law of Independent Assortment
● Monohybrid Cross and the Punnett Square
● The Test Cross
● Calculation of Phenotype Ratios
● Autosomal Dominant Inheritance
● Autosomal Recessive Inheritance
● Calculating Probabilities in Pedigrees

2.2 Cell Division and Chromosome Heredity: The cell cycle is an ordered series of events involving cell growth and cell division that produces two new daughter cells. Cells on the path to cell division proceed through a series of precisely timed and carefully regulated stages of growth, DNA replication, and division that produces two identical (clone) cells. Body cells divide during mitosis. Through this process, two identical copies of the parent cell are created

Meiosis is a specialized type of cell division that reduces the chromosome number by half. This process occurs in all sexually reproducing single-celled and multi-cellular Eukaryotes, including
animals, plants, and fungi. The nuclei resulting from meiosis are never genetically identical. Mammalian sex is determined genetically by the combination of X and Y chromosomes. Individuals homozygous for X (XX) are female and heterozygous individuals (XY) are male.

● Cell Division by Mitosis
● The Cell Cycle
● Mitosis and Cytokinesis
● Comparing Meiosis and Mitosis
● Sex-linkage and Role of Chromosomes in Sex Determination
● X-linked Dominant or Recessive Inheritance
● Expression of X-linked Recessive Traits
● X-linked Dominant Transmission

Gene expression can be affected by interactions with other genes. These differences are observable on a molecular basis. When there are multiple alleles present on one gene, how does it affect gene interaction? Gene mutations prevent proteins from working properly. Whether or not genes are linked, the strength of the genes, and therefore their distance from each other help us to map genomes. And how do you piece these fragments together to deduce our evolutionary history?

3.1 Gene Interaction: The recessive phenotype is only observed in homozygous recessive individuals. The phenotype of a fully dominant mutation is seen in both heterozygous and homozygous individuals. A variation on incomplete dominance is codominance, in which both alleles for the same characteristic are simultaneously expressed in the heterozygote.
In incomplete dominance there is an “intermediate” phenotype that is a blend between the dominant/recessive allele. Observing the ratios expressed in a cross can help you determine how genes are interacting.

● The Molecular Basis of Genetic Dominance
● Recessive Mutations
● Fully Dominant Mutations
● Codominance and Incomplete Dominance
● The Allelic Series of the C Gene
● Complementation Tests
● Complementary Gene Interaction (9:7 Ratio)
● Duplicate Gene Interaction (15:1 Ratio)
● Dominant Gene Interaction (9:6:1 Ratio)
● Recessive Epistasis (9:3:4 Ratio)
● Dominant Epistasis (12:3:1 Ratio)
● Dominant Suppression (13:3 Ratio)
● Strategies for Studying Gene Interactions
● Lethality
● Pleiotropy

3.2 Genetic Linkage and Mapping in Eukaryotes: Information about genetic linkage and how specific genes interact can help us map where certain genes are. Linked genes are always
syntenic and near one another, genetic linkage leads to more gametes with parental allele combinations than nonparental ones, and crossing over is less likely to occur between closely linked genes.

The three step-process for studying gene interactions includes finding two mutants affecting the same phenotype, doing a complementation test, and performing a dihybrid cross. Genetic mapping can offer firm evidence that a disease transmitted from parent to child is linked to
one or more genes or provide clues about which chromosome contains the gene.

● Chromosomal Theory of Inheritance
● Homologous Recombination
● Genetic Linkage and Mapping
● Strategies for Studying Gene Interactions
● Mapping Genetic Synteny and Comparative Genomics
● Linked Genes vs. The Law of Independent Assortment
● Complete vs. Incomplete Genetic Linkage
● Linkage Analysis
● Recombination Frequency
● Genetic Distance and Genetic Maps
● Calculating Recombination Frequency
● Recombination Results from Crossing Over
● Three-Point Test-Cross Analysis
● Double Crossover Probability
● Interference
● Correction of Genetic Distances

Why do organisms resemble their parents? How are these traits passed along between generations? How has our planet been populated by such diverse life forms? Learn how the properties of organisms pass from parents to offspring. Learn how populations evolve by natural selection, genetic drift, and random mutation— processes that can even generate new species.

4.1 Population Genetics: A null hypothesis is the default position, meaning there is no
association between two phenomena. Chi-square analysis is performed using the chi-square table. The interpretation of the chi- square values is done by means of the probability value (P-value). The forces of evolution can create or destroy allele diversity. By applying knowledge on allelic frequencies and the Hardy-Weinburg equilibrium, we can predict proportion of carriers and offspring. Identical by descent (IBD) describes a matching piece of DNA shared by people
who have a common ancestor.

● Null and Alternative Hypotheses
● Dihybrid Test Cross and the Null Hypothesis
● Pearson’s Chi-Squared Test
● P Value, Degrees of Freedom and Chi-Square Analysis
● Genetic Polymorphism
● Evolutionary Forces and Estimation of Genotype Frequencies
● The Hardy-Weinberg Equilibrium: Assumptions and Predictions
● The Hardy-Weinberg Equilibrium for More than Two Alleles
● The Wahlund Effect
● Non-Random Mating: Assortative Mating and Inbreeding
● Calculating Identical by Descent (IBD) on Pedigrees

4.2 Evolutionary Genetics: Evolution will occur by natural selection if variation in reproductive success has a heritable basis. Selection can also be designed as the variation in average reproductive success among phenotypes. Fitness differences are measured by the selection coefficient. Selection works against certain alleles in the gene pool. Heterozygote advantage preserves genetic diversity. Individuals with the most favorable genotype have higher success at producing offspring, meaning their genotypes are more widely spread in the population.

Genetic drift is the random chance that influences genotypic frequency, seen most strongly in small populations because of little to no difference in fitness. A mechanism that increases the level of genetic drift in small populations is the genetic bottleneck, in which a relatively large population is reduced due to a catastrophic event independent of natural selection. The frequency of an allele depends on the population size instead of fitness.

● Selection and Fitness
● Differential Reproduction and Relative Fitness
● Modeling Directional Selection
● Modeling Heterozygote Advantage
● Equilibria
● Genetic Drift and Changes in Allele Frequency
● The Founder Effect
● Genetic Bottlenecks
● Genetic Drift and Population Size
● Balance Between Mutation and Drift
● Balance Between Mutation and Selection

4.3 Quantitative Genetics: Discrete traits can only take certain fixed values while continuous traits can take a conceivable value within an observed range. The more phenotypes that are present in a limited scale of measurement, the narrower is the slice of the distribution each category occupies and the less obvious the demarcation between categories may become. The segregation of alleles of multiple genes and environmental factors can affect quantitative traits.

Mathematical models can be applied to any quantitative traits to measure phenotypic variation. Deviations from the mean due to genetic and environmental factors are also accounted for. The amount of phenotypic variation that is due to genetic variation is called Broad- Sense Heritability. Genetic variance can further be organized into three categories: additive, dominance, and interactive variance. Narrow-sense heritability measures the proportion of total phenotypic variation that is due to additive genetic variation.

● Discontinuous vs. Continuous Variation
● Genetic Potential
● Major Genes and Additive Gene Effects
● Continuous Phenotypic Variation from Multiple Additive Genes
● Allele Segregation in Quantitative Trait Production
● Genetic and Environmental Deviations
● Measuring Quantitative Variation
● Genetic and Environmental Variance
● Broad-Sense Heritability
● Partitioning Genetic Variance
● Narrow-Sense Heritability

Proteins are synthesized from code in DNA through a process that is explained by the central dogma. Learn about the flow of genetic information: from DNA to RNA to proteins and beyond. How is our genetic information stored, retrieved, and ultimately expressed in the molecular machines (proteins) that make us who we are?

5.1 DNA Structure and Replication: How is hereditary information stored in our cells? Learn about DNA, its structure, function, and replication. DNA is the means through which
genetic information is passed on, and it has specific qualities that make it capable of doing this job. Antiparallel orientation of the two halves of the double helix bring the partial charges of complementary nucleotides into alignment. Chargaff’s rule states that DNA from any cell of all organisms should have a 1:1 ratio, meaning that the amount of adenine:thymine and
cytosine:guanine is the same. Eukaryotic genomes are much more complex and larger in size than prokaryotic genomes. The loss of DNA at telomeres is what causes aging.

● DNA as Hereditary Material
● DNA Strand Elongation
● Complementary DNA Nucleotide Pairing
● Pyrimidines, Purines, and Hydrogen Bond Potential
● Base Pairing and Hydrogen Bond Potential
● The Twisting Double Helix
● Chargaff’s Rules
● Replication Initiation in Bacteria
● Prokaryotic DNA Replication Enzymes
● Simultaneous Synthesis of Leading and Lagging Strands
● DNA Replication in Eukaryotes
● DNA Proofreading and Finishing Replication
● Telomere Replication
● Telomerase and Aging

5.2: Gene Mutations, Proofreading and Repair: Find out about different types of mutations and the mechanisms of repair. Mutations are rare, random, and usually deleterious. By changing a gene’s instructions for making a protein, a mutation can cause the protein to malfunction or to be missing entirely. When a mutation alters a protein that plays a critical role in the body, it can disrupt normal development or cause a medical condition.

The three types of base-pair mutations are silent, missense, and nonsense mutations. Some point mutations alter the amount of protein product produced by a gene. Because errors in DNA replication can cause such drastic changes, the process of replication includes a proofreading step. Factors like physical trauma, chemical exposure, or biological agents can generate mutations. These are called mutagens.

● Tautomeric Shift-Induced Mismatches
● Types of Base-Pair Substitution Mutations
● Point Mutations: Frameshift Mutations and
● Regulatory Mutations
● DNA Proofreading
● Causes of Mutations
● Video: Mutations induced by chemical or ionizing radiation
● Causes of Mutations: Chemical Mutagens – Nucleoside Analogs and
● Intercalating Agents
● Causes of Mutations: Radiation
● The Ames Test
● Direct Repair of DNA Damage: Mismatch Repair
● Repair of Thymine Dimers

5.3 Transcription and RNA Processing: How does the information of genes come to be expressed as proteins? Learn about the first step of this process – the transcribing of DNA in
messenger RNA. Both prokaryotes and eukaryotes perform fundamentally the same process of transcription, with the important difference of the membrane-bound nucleus in eukaryotes.
Transcription in prokaryotes has three phases: initiation, elongation, and termination. Eukaryotes use three different polymerases, RNA polymerases I, II, and III, all structurally distinct from the bacterial RNA polymerase. Unlike the prokaryotic polymerase that can bind to a DNA template on its own, eukaryotes require several other proteins, called transcription factors, to first bind to the promoter region and then help recruit the appropriate polymerase.

● Transcription in Prokaryotes
● Elongation and Termination in Prokaryotes
● Prokaryotic Termination Signals
● Genome Wide Association Studies and SNPs
● Transcription in Eukaryotes
● Structure of an RNA Polymerase II Promoter
● Transcription Factors for RNA Polymerase II
● Elongation and Termination in Eukaryotes
● mRNA Processing in Eukaryotes
● Processing of tRNA and rRNAs

5.4 Translation: How does the information of genes come to be expressed as proteins? Learn about the final step of this process – the translating of messenger RNA into chains of amino acids, the building blocks of proteins.

Genes contain the information necessary for living cells to survive and reproduce. Translation is the last step of the central dogma. With gene expression RNA is turned into amino acids, the monomers that make up proteins. The synthesis of proteins consumes more of a cell’s energy than any other metabolic process. The molecules which carry out translation are mRNA, ribosomes, and tRNA/tRNA charging enzymes.

● Gene Structure
● Gene Expression
● The Genetic Code
● Amino Acids and Protein Synthesis
● Protein Synthesis Machinery: Ribosomes and Transfer RNAs (tRNAs)
● Initiation of Translation
● Elongation and Termination
● Protein Folding, Modification, and Targeting
● Translation in Prokaryotes vs. Eukaryotes

5.5 Transcription Control of Gene Expression: How do organisms like you and me control the expression of our genes? It turns out that we can learn a lot from how bacteria regulate the expression of their genes to break down simple sugars.

Complementation analysis can help us understand structural gene mutations. Bacteria typically have the ability to use a variety of substrates as carbon sources. Eukaryotic gene expression is much more complex; multiple processes affect which genes are expressed.

● Gene Regulation
● Prokaryotic Gene Regulation
● Control of Gene Expression in Prokaryotes
● The lac Operon: An Inducible Operon
● Analysis of Structural Gene Mutations
● The lac Operon: Activation by Catabolite Activator Protein
● The trp Operon: A Repressible Operon
● Control of Gene Expression in Eukaryotes
● Eukaryotic Epigenetic Gene Regulation
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Modern Molecular Genetics: Molecular genetic analytical methods are based on the natural steps of DNA replication. These methods can help us visualize and interpret larger-scale meanings of small, genetic details for application in the real world.

6.1 Recombinant DNA Technology: Gel electrophoresis is largely dependent upon the fact that nucleic acids are negatively charged. This process separates molecules on the
basis of size, allowing us to visualize similarities/differences between samples of DNA.

Since 2005, automated sequencing techniques used by laboratories fall under the umbrella of next generation sequencing. Nucleic acid samples, such as fragmented genomic DNA and RNA extracts, can be probed for the presence of certain sequences.

Genetic engineering revolves around recombinant DNA technology. Molecular cloning utilizes a set of methods to construct recombinant DNA to incorporate it into a host organism. The most commonly used mechanism for introducing engineered plasmids into a bacterial cell is transformation, a process in which bacteria take up free DNA from their surroundings.

● Polymerase Chain Reaction (PCR)
● Agarose Gel Electrophoresis
● Dideoxynucleotide DNA Sequencing
● Next Generation Sequencing
● Hybridization, Southern Blotting, and Northern Blotting
● Recombinant DNA Technology
● Restriction Enzymes and Ligases
● Plasmids as Vectors
● Molecular Cloning using Transformation
● Reproductive Cloning
● Genetic Engineering

6.2 Personal Genomics: Your genome is your entire genetic makeup and is highly sensitive data. The genetic factors can contribute to human disease. Carrier testing determines whether parents may be carriers of certain diseases, informing their choices in having children.

Though genetic tests have been used for decades through forensics, newborn screening, diagnostic testing, and prenatal testing, it is only recently that these services have been commercialized. Though it may not seem immediately obvious, your genetic information could easily be used against you. This is called genetic discrimination.

● Types of Genetic Test
● History of Personal Genomics
● Modernization of Genome Mapping
● Commercialization of Personal Genomics
● Controversy Surrounding Personal Genomics
● Genetic Discrimination: Genomes and the Law
● Genome Wide Association Studies and SNPs

6.3 Epigenetic Inheritance: The word “epigenetic” literally means “in addition to changes in genetic sequence.” The term has evolved to include any process that alters gene activity without changing the DNA sequence and leads to modifications that can be transmitted to daughter cells. Epigenetic processes are natural and essential to many organism functions, but if they occur improperly, there can be major adverse health and behavioral effects.

● Discovery of Epigenetics
● Molecular Epigenetics: How Changes Occur
● Effects of Epigenetics
● Epigenetic Insights from Twins
● Spanning Generations