Ch 3: ILTS Environmental Science: Principles of Heredity and Biological Evolution

About This Chapter

Let us teach you about principles of heredity and biological evolution. The video lessons and self-assessment quizzes in this chapter can prepare you to answer questions about life science on the ILTS Science: Environmental Science content area test.

ILTS Science: Environmental Science - Principles of Heredity and Biological Evolution: Chapter Summary

Do you remember Mendel's first and second laws? Can you recall the difference between prezygotic and postzygotic barriers? If not, you might want to use this chapter on principles of heredity and biological evolution as a refresher before taking the Illinois Licensure Testing System (ILTS) Science: Environmental Science content area test. In addition to learning to apply Mendel's laws of segregation and independent assortment and exploring speciation, you'll examine the following topics:

  • Regulation of gene expression
  • Gene function with an emphasis on the molecular basis of inheritance
  • Exceptions to simple dominance
  • Exceptions to independent assortment
  • Processes of change at the microscopic and macroscopic levels
  • Allopatric and sympatric speciation
  • Natural selection and adaptation
  • The Hardy-Weinberg equilibrium model
  • Theory of evolution

ILTS Science: Environmental Science - Principles of Heredity and Biological Evolution Objectives

This ILTS content area test, which is offered just six times per year, features 125 multiple-choice questions. The questions cover six subareas of environmental science, including life science; this subarea might include questions about principles of heredity and biological evolution. The ILTS environmental science content area test is one component of the certification process for aspiring environmental science teachers in Illinois. You also must meet education and practicum requirements if you want to work at a public school in this state.

The brief, online video lessons in this chapter were developed by experienced professional educators. Each video is accompanied by a self-assessment quiz, which can help you gauge the areas in which you're proficient and those in which you could use additional study time.

16 Lessons in Chapter 3: ILTS Environmental Science: Principles of Heredity and Biological Evolution
Test your knowledge with a 30-question chapter practice test
Regulation of Gene Expression: Transcriptional Repression and Induction

1. Regulation of Gene Expression: Transcriptional Repression and Induction

Do our genes work the same way all the time? How do we regulate the expression of our genes? Explore the various ways organisms control gene transcription through repression and induction of operons.

Mendel's First Law: The Law of Segregation

2. 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

3. 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 Second Law: The Law of Independent Assortment

4. 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.

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?

Postzygotic Reproductive Barriers: Definition & Examples

8. 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.

Prezygotic Reproductive Barriers & Speciation: Definition & Examples

9. 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.

Speciation: Allopatric and Sympatric Speciation

10. 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.

Natural Selection & Adaptation: Definition, Theory & Examples

11. 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

12. 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.

Hardy-Weinberg Equilibrium II: The Equation

13. 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

14. 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.

Hardy-Weinberg Equilibrium I: Overview

15. 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.

Theories of Evolution: Lamarck vs. Darwin

16. 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.

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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