Ch 6: Biology: Genetics

About This Chapter

The short and engaging lessons in this chapter make it easy for you to fully understand genetics in biology. Boost your comprehension by reviewing topics like Mendel's first and second laws, complete and incomplete dominance and meiosis.

Biology: Genetics - Chapter Summary

Enjoy this in-depth look at genetics in biology, which is offered in the form of fun video lessons. Get a quality overview of genetics, and review chromosomal linkage, polygenic traits and much more. Once you've completed this chapter, you will be prepared to:

  • List properties of alleles
  • Describe Mendel's first law and the application of his first and second laws
  • Share details about exceptions to simple dominance and independent assortment
  • Define polygenic traits, complete and incomplete dominance and heterozygous
  • Provide the formula and calculate relative risk for disease
  • Explain chromosomal linkage and crossing over
  • Discuss model organisms and pedigree analysis in human genetics
  • Detail how sex is determined in drosophilia

Review the lessons in any sequence you desire from your computer or mobile devices. Lessons are accessible any time, day or night. Beneath each video lesson is a full transcript with easily identifiable vocabulary words that can deepen your understanding of genetics in biology. When ready, test your knowledge of the lessons by taking short quizzes. A chapter exam is also available to reinforce lesson concepts.

17 Lessons in Chapter 6: Biology: Genetics
Test your knowledge with a 30-question chapter practice test
Genetics: Heredity, Traits & Chromosomes

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.

Properties of Alleles

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.

Mendel's First Law: The Law of Segregation

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.

Application of Mendel's First Law

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.

Mendel's Dihybrid Cross Example: Practice & Ratio

5. 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!

Exceptions to Simple Dominance: Codominance and Incomplete Dominance

6. 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.

Exceptions to Independent Assortment: Sex-Linked and Sex-Limited Traits

7. 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?

Polygenic Traits: Definition & Examples

8. 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.

Relative Risk for Diseases: Formula & Calculation

9. Relative Risk for Diseases: Formula & Calculation

The relative risk is important to determine risk factors for particular diseases. In this lesson we will define the relative risk and learn how to calculate it.

Crossing Over & Gene Linkage: Definition, Importance & Results

10. 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.

Human Genetics: Multifactorial Traits & Model Organisms

11. Human Genetics: Multifactorial Traits & Model Organisms

How do we study human genetics when most traits arise from multiple genes? It's certainly more complicated that drawing a simple Punnett square. Never fear, for model organisms are here!

Pedigree Analysis in Human Genetics: Tutorial

12. Pedigree Analysis in Human Genetics: Tutorial

One of the oldest genetic techniques is pedigree analysis, and yet it is still used every day all around the world by doctors, geneticists, and genetic counselors. Building and reading a pedigree is actually fairly easy if you know what the symbols mean. In fact, it's so easy that you can learn how to do it in less than ten minutes if you watch this video!

Complete Dominance: Definition & Examples

13. Complete Dominance: Definition & Examples

This lesson examines complete dominance, which is one of the ways the genes you get from your parents can show up. It also covers the vocabulary needed to understand complete dominance as well as examples.

Incomplete Dominance: Definition & Example

14. Incomplete Dominance: Definition & Example

Dominant/recessive inheritance is a common topic in genetics. Incomplete dominance is a naturally occurring phenomenon that may be present during the expression of this type of inheritance. This article describes incomplete dominance and goes over examples found in nature.

How Sex is Determined in Drosophila

15. How Sex is Determined in Drosophila

In humans, the Y chromosome denotes a male. In the model organism Drosophila, it is the number of X chromosomes and autosome sets that determine sex rather than the presence of a Y chromosome. In this lesson, we'll learn about what makes normal male and female flies, as well as the super-normal!

What is Heterozygous? - Definition, Traits & Example

16. What is Heterozygous? - Definition, Traits & Example

We all have two copies of each of our genes. If your two copies are slightly different than each other, congratulations, you're heterozygous! Learn how heterozygosity occurs, and why it can be a good thing to be slightly mismatched.

Meiosis: Comparison to Mitosis, Crossing Over & Process

17. Meiosis: Comparison to Mitosis, Crossing Over & Process

Welcome to meiosis, a realm of division doubled for reproduction untroubled. You'll get a preview of both divisions of meiosis and see what it takes to go from a diploid cell to a haploid gamete.

Chapter Practice Exam
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