About This Chapter
Transmission/Mendelian Genetics - Chapter Summary and Learning Objectives
Gregor Mendel provided us with a basic understanding of the role of genetics in inheritance. In this chapter, you'll watch video lessons that discuss Mendel's laws, along with some other basic information about genetics. Our instructors will take you through lessons that cover:
- The application of Mendel's laws
- The chi-square test
- Genotypes and phenotypes
- Homozygous and heterozygous
- Polygenic traits
- Nature vs. nurture
|Overview of Genetics||Study the basics of genetics, including traits, genotypes, phenotypes, chromosomes, genes and alleles.|
|Properties of Alleles||Take a look at alleles and how they pair up.|
|Mendel's First Law: The Law of Segregation||See how allele separation forms the basis for this law.|
|Application of Mendel's First Law||Discover how Mendel's first law is confirmed and what it proves.|
|Mendel's Second Law: The Law of Independent Assortment||Explore what happens with the segregation of two genes as you study Mendel's second law.|
|Application of Mendel's Second Law||Analyze how Mendel's second law works.|
|Complementation Tests||Learn what a complementation test is and what it is used for.|
|Chi-Square Test||Examine what a chi-square test is and how it works.|
|Exceptions to Simple Dominance: Codominance and Incomplete Dominance||Study codominance and incomplete dominance.|
|Polygenic Traits||Explore inheritance patterns and how they exhibit as traits in individuals.|
|Epistasis||Analyze the work of modifier genes.|
|Imprinting||See how imprinting changes the normal pattern of inheriting genes from the mother and father.|
|Exceptions to Independent Assortment: Sex-Linked and Sex-Limited Traits||See why some traits only affect a certain gender as you explore exceptions to independent assortment.|
|Chromosomal Linkage and Crossing Over||Discover an exception to Mendel's second law.|
|Genetic Contribution - Assigning Percentages to Nature and Nurture||Explore the concept of nature vs. nurture.|
|Genotype-Environment Interactions||Discover why some organisms are genetically predisposed to respond to environmental conditions differently than others.|
1. Genetics: Heredity, Traits & Chromosomes
We view manipulation of genes in our crops and livestock as a recent development. Yet, man has been manipulating the genetic makeup of his food for thousands of years through cultivation and breeding. This lesson will begin to help you understand how genetics works.
2. Properties of Alleles
What is a dominant phenotype and how will it affect Adrian's flying hamster research? Tune in as he studies homozygous and heterozygous genotypes and the phenotypes they produce.
3. Mendel's First Law: The Law of Segregation
Breaking up is a hard thing to do, but homologous chromosomes always go their separate way. What effect does chromosome segregation have on genetics? We look once more to Adrian's flying hamsters for answers.
4. Application of Mendel's First Law
Hollywood Squares? No, it's Punnett Squares! Those wacky diagrams are a geneticist's best friend. See how they turn geneticists into soothsayers, predicting the genotypic and phenotypic future.
5. Mendel's Second Law: The Law of Independent Assortment
Understanding how Mendel's law of independent assortment describes inheritance of genes is as easy as flipping a coin. Grab a few coins, cue up the video and see how.
6. Mendel's Dihybrid Cross Example: Practice & Ratio
Oh no! Twice the genes and sixteen genotypes - a dihybrid cross seems overwhelming to understand. Never fear though, Punnett squares will save the day!
7. Exceptions to Simple Dominance: Codominance and Incomplete Dominance
Have you ever wondered what it means if someone is a universal donor or acceptor of blood? See how genetic interactions play a key role in this trait.
8. Exceptions to Independent Assortment: Sex-Linked and Sex-Limited Traits
More men are color blind compared women. But often, not every brother, cousin or uncle in a family tree is color blind. Why not? How can genetics explain this seemingly complex inheritance pattern?
9. Crossing Over & Gene Linkage: Definition, Importance & Results
During this latest development of his flying hamster experiments, Adrian must learn about linked genes and recombinant chromosomes to unlock the mystery of the fire-breathing hamster. In this lesson, you'll look at another exception to Mendel's law of independent assortment.
10. Complementation Tests: Alleles, Crosses & Loci
Don't judge an organism by its phenotype; sometimes, two organisms will have the same phenotype but completely different genotypes. In this lesson, we'll learn how a complementation test can identify if mutations occurred within the same gene or different genes.
11. Epistasis: Definition & Examples
Labradors come in three different colors due to two different genes. In this lesson, find out how epistasis works as one phenotype is controlled by the products from two or more genes.
12. Lethal Alleles: Definition & Examples
Some alleles are recessive, some are dominant, and some are just plain bad. In this lesson, we'll learn about how rare lethal alleles can affect the survival of an organism. Specifically, we'll talk about how something like coat color can be lethal in agouti mice.
13. The Chi-Square Test
What if you expect one thing, but get another? The chi-square test is a method of statistical analysis that can help us identify if the results from a genetic cross are simply due to chance, or if something else is happening. Learn about the chi-square test in this lesson.
14. Polygenic Traits: Definition & Examples
If variety is the spice of life, polygenic inheritance is one genetic mechanism giving us a continuous range of possibilities. In this lesson, learn how a polygenic trait, like height, can be controlled by multiple genes.
15. Genotype-Environment Interaction and Phenotypic Plasticity
It's not just what's in your genes. In this lesson, we'll begin to explore how some phenotypes are influenced by the interaction between a genotype and the environment. Further, some organisms rely on phenotypic plasticity to change in response to the environmental changes.
16. The Broad-Sense Heritability Equation
Heritability describes how a phenotype is affected by genetic variation. Who you are is more than just your DNA - it's somewhat influenced by things, like what you eat and where you live. In this lesson, find out how geneticists account for variations using the broad-sense heritability equation.
17. Using Twin Studies to Determine Heritability
A twin can be more than a built-in buddy for life. Scientists can use monozygotic and dizygotic twin pairs to study the heritability of just about anything, from cancer to behavior.
18. Genomic Imprinting: Definition and Examples
Your parents may have 'imprinted' many things on you, such as how to act at the dinner table and how to spend your money. Your parents also 'imprinted' some of your genes. In this lesson, we'll learn about how genomic imprinting is a form of transcription regulation that is a type of epigenetic inheritance.
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