About This Chapter
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.
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 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!
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.
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?
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.
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.
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.
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!
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!
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.
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.
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!
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.
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.
Earning College Credit
Did you know… We have over 160 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.
To learn more, visit our Earning Credit Page
Transferring credit to the school of your choice
Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.
Other chapters within the PCAT: Study Guide & Test Prep course
- Verbal Ability: Analogies
- Verbal Ability: Sentence Completion
- Biology: Cell Structure & Division
- Biology: Cellular Processes
- Biology: DNA & Enzymes
- Animal & Human Behavior
- Biology: Evolution & Natural Selection
- Speciation, Extinction & Taxonomy
- Biology: Intro to Nutrition
- Biology: Nutrition - Carbohydrates
- Biology: Nutrition - Lipids
- Protein in Nutrition
- Minerals & Nutrition
- Vitamins in Nutrition
- Biology: Diseases & Prevention
- Biology: Types of Diseases
- Microrganisms & Microbial Ecology
- Medical Microbiology
- Microbiology: The Immune System
- Structures of Human Anatomy & Physiology
- Human Skeletal System
- Muscular System
- The Human Nervous System
- Human Circulatory System Basics
- The Circulatory System, Blood & Blood Vessels
- Respiratory System
- Urinary Systems & Structures
- Functions of the Human Digestive System
- Overview of the Endocrine System
- Male Reproductive System
- Female Reproductive System
- Integumentary System Overview
- The Five Senses of the Human Body
- The Atom and Atomic Theory
- Chemical Bonding in Physical Chemistry
- Types of Reactions in Chemistry
- Equilibrium in Chemistry
- Overview of Stoichiometry
- Properties of Liquids & Solids
- Gas Laws
- Kinetics & Thermodynamics
- Elements, Compounds & Mixtures
- Nuclear Processes
- Organic & Inorganic Chemistry
- Reading Comprehension & Analysis
- Fractions & Percents
- Solving Algebraic Equations
- Linear Equations Overview
- Inequalities Overview
- Understanding the Basics of Functions
- Interpreting Tables & Plots
- Basic Statistics & Probability
- Linear Regression & Correlation
- Solving Exponential & Logarithmic Functions
- Complex Numbers & Vectors
- Limits of Functions
- Overview of Continuity
- Rate of Change & Calculating Derivatives
- Integrals & Antiderivatives
- PCAT Flashcards