Ch 22: Praxis Biology & General Science: Evolution

About This Chapter

Let us teach you about the theory of evolution. The video lessons and self-assessment quizzes in this chapter can help you correctly answer questions about evolution and classical genetics on the Praxis II Biology and General Science test.

Evolution - Chapter Summary

Get an overview of the Hardy-Weinberg equilibrium, along with lessons specific to the equation and evolutionary agents, in this chapter on genetics. We've designed this series of brief video lessons to help you prepare for the Praxis II: Biology and General Science test, which you might need to pass to earn your teacher certification. In addition to the Hardy-Weinberg principle, this chapter addresses natural selection and adaptation, as well as the difference between endangered and threatened species. Additional topics include the following:

  • Types of natural selection
  • Gene pool isolation
  • Prezygotic barriers
  • Postzygotic isolation
  • Adaptive radiation and co-evolution
  • Evidence for evolution
  • Gradualism vs. punctuated equilibrium
  • What is extinction?

Evolution Objectives

Depending on the state where you plan to teach, you might have to take the Praxis II: Biology and General Science test to earn certification to work in a public high school. This test consists of 120 multiple-choice questions, which you'll have two hours to complete. Evolution and classical genetics is one of the eight content categories covered by the Praxis II; this category comprises approximately 15% of the test.

Our team of professional educators designed this online chapter on evolution to be both comprehensive and engaging. The videos can typically be viewed in less than 10 minutes, or you can read the accompanying transcripts. To test your mastery of the presented material, you can take the self-assessment quizzes in this chapter. These short, multiple-choice tests are modeled after the Praxis II, which can give you a leg up on test day.

11 Lessons in Chapter 22: Praxis Biology & General Science: Evolution
Test your knowledge with a 30-question chapter practice test
Theories of Evolution: Lamarck vs. Darwin

1. Theories of Evolution: Lamarck vs. Darwin

We'll look at the interplay between population genetics and environment. Are traits individually acquired or do entire populations evolve? The flying hamsters and a few other notable experiments will provide the answers.

Hardy-Weinberg Equilibrium I: Overview

2. Hardy-Weinberg Equilibrium I: Overview

In this lesson, we'll examine population genetics in greater detail. We'll also explore notions of Hardy-Weinberg equilibrium for large, stable populations. Is the genetic makeup of our flying hamster population changing? The Hardy-Weinberg equilibrium can serve as a reference point as we try to answer population genetics questions.

Hardy-Weinberg Equilibrium II: The Equation

3. Hardy-Weinberg Equilibrium II: The Equation

The Hardy-Weinberg equilibrium equation is represented by a polynomial, so we'll have to do some calculations. Don't be intimidated; a few coin tosses can help us make sense of allelic frequencies in a given gene pool.

Hardy-Weinberg Equilibrium III: Evolutionary Agents

4. Hardy-Weinberg Equilibrium III: Evolutionary Agents

In this lesson, you'll learn how the Hardy-Weinberg equation relates to different evolutionary agents and population changes. Discover how the equation may be used to discover populations that are not in equilibrium.

Natural Selection & Adaptation: Definition, Theory & Examples

5. Natural Selection & Adaptation: Definition, Theory & Examples

How does natural selection help shape the amazing types of animals we witness around us? In this lesson, we'll explore adaptations and what they can tell us about a species' past evolution.

Natural Selection: Definition, Types & Examples

6. Natural Selection: Definition, Types & Examples

We'll take a look at the types of natural selection that can occur. From flying hamsters to moths, you'll start to grasp the different paths organisms can take as they respond to their changing environments over time.

Speciation: Allopatric and Sympatric Speciation

7. Speciation: Allopatric and Sympatric Speciation

Discover the definition of a species and learn more about how species split. Find out common terms related to the splitting of species and study what role polyploidy plays in the development of a species.

Prezygotic Reproductive Barriers & Speciation: Definition & Examples

8. Prezygotic Reproductive Barriers & Speciation: Definition & Examples

We may take for granted why animals choose to mate with other animals of similar appearance, but it's not that simple. There are actually biological barriers to reproduction that can prevent even seemingly closely related species from reproducing. This lesson looks at one such category of hindrances, prezygotic barriers, which make fertilization impossible.

Postzygotic Reproductive Barriers: Definition & Examples

9. Postzygotic Reproductive Barriers: Definition & Examples

Do flying hamsters represent a separate species from your run-of-the-mill hamsters? We'll get to the bottom of this by performing crosses between the two hamster types. You'll explore postzygotic reproductive barriers and their possibly tragic consequences.

What Is Extinction? - Defining Background and Mass Extinction

10. What Is Extinction? - Defining Background and Mass Extinction

In this lesson you'll discover what the term 'extinction' means as well as learn the two different types of extinction: mass extinction and background extinction. You will also discover how humans contribute to extinction events.

Differences Between Endangered Species and Threatened Species

11. Differences Between Endangered Species and Threatened Species

In this lesson you'll learn about two terms that describe species with very low population numbers: threatened and endangered. You'll discover why species numbers decline and how we can keep the species that are threatened or endangered from going extinct.

Chapter Practice Exam
Test your knowledge of this chapter with a 30 question practice chapter exam.
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Practice Final Exam
Test your knowledge of the entire course with a 50 question practice final exam.
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