About This Chapter
Praxis Biology: Population Ecology - Chapter Summary
This chapter is designed to enhance your understanding of how inhabitants relate to their environment while preparing for the Praxis Biology exam. In order to help you answer the test questions correctly, the lessons cover a wide variety of topics, including:
- Energy flow, food chains and trophic levels in ecosystems
- Competition and predator/prey relationships, including camouflage, mimicry and warning coloration
- Symbiotic relationships, such as commensalism, mutualism and parasitism
- Populations and population changes, including density, survivorship and life histories
- Carrying capacity, dispersion and migration
- Ecological succession and changes in diversity
- Extinction, including background, environmental factors, genetic diversity and mass extinction
- Endangered, introduced, invasive and threatened species
Taught by professional instructors, the lessons are composed of brief videos and lesson summaries, which cover definitions, models and theories of populations, including factors and growth. These easy-to-understand presentations can provide you with the organized guidance and informational support you need to prepare for the Praxis Biology test.
Objectives of the Praxis Biology Test: Population Ecology Course
The Praxis Biology exam is a multiple-choice assessment available in either computer-based or paper format. The test is used to determine how ready a prospective teacher might be to teach secondary school biology. Approximately 15% of the questions on the test pertain to ecology.
The test covers topics normally found in college-level, introductory biology courses and address biological concepts, data analysis, definitions and methods, among other areas. As secondary school biology teachers must have an advanced-level understanding of the subject, the exam also includes some questions that are more complex in nature. To help you prepare, these biology lessons include online self-assessment quizzes that are similar in content and format to those found on the actual test.
1. The Environment, Levels of Ecology and Ecosystems
Do you know the difference between an environment and an ecosystem? In this lesson, you'll find out what makes an environment, and what makes an ecosystem. You'll also learn what ecology is and some of the ways that scientists study ecology using organisms, populations, communities, ecosystems and even the entire biosphere.
2. Ecosystems, Habitats and Ecological Niches
Check out this video lesson to understand the many complex aspects of an ecosystem. See how animals live in habitats and survive amongst their surroundings.
3. Food Chains, Trophic Levels and Energy Flow in an Ecosystem
In this lesson, you'll learn about food chains, food webs, and the different roles that organisms play in an ecosystem. You'll also learn about how energy flows through an ecosystem.
4. Interspecific Competition, Competitive Exclusion & Niche Differentiation
What happens when two similar species that consume the same resources occupy the same space? Interspecific competition, that's what! Watch our video lesson to learn about the outcomes of this ecological battle.
5. Predator/Prey Interactions, Camouflage, Mimicry & Warning Coloration
You probably know that skunks can be quite stinky, bees sting and monarch butterflies are pretty, but do you know why? This lesson will introduce you to the reasons why some animals look or act the way they do and how these things relate to the predator/prey relationship.
6. Symbiotic Relationships: Mutualism, Commensalism & Parasitism
If your cat or dog has ever had fleas, you've witnessed symbiosis in action. In this lesson, learn the many types of symbiosis in biology, and how these relationships can have a positive, negative, or neutral effect on the individual species.
7. Populations: Density, Survivorship and Life Histories
Have you ever wondered how biologists determine the populations of animals in a particular geographic area? Watch this video lesson to find out, and discover how scientists look at the survivorship and life histories of many different species.
8. Population Change from Aging, Death, and Migration
Fertility, mortality and migration are principal determinants of how a population can change, and they are at the very core of demographic studies. In this lesson, we will discuss how a population can change from fertility (birth), mortality (death), and migration.
9. Carrying Capacity, Migration & Dispersion
Have you ever wondered why some types of birds fly south in the winter or why some animals form territories? Watch this video to learn about a species' maximum growth capabilities, the way its members group themselves and why they might migrate to new locations every year.
10. Dispersal, Colonization, and Island Biogeography
Have you ever gone in your backyard and discovered a wild raspberry bush that has never been there before? How did it get there? Why is there only one bush year after year? In this lesson, you'll study how plant and animal species colonize in new areas through dispersal and immigration and how some species thrive in a new area while others fail.
11. Conservation Biology, Habitat Fragmentation, and Metapopulations
It's becoming harder to conserve large, unbroken tracts of wilderness. Is there another way for conservation biologists to ensure the survival of a species? In this lesson, you'll learn about habitat fragmentation and metapopulations.
12. Ecological Succession: From Pioneer to Climax Communities
Just as people grow and change so, too, do ecosystems. Watch this lesson to learn about ecological succession from the beginning stages of development to a community's ultimate destination, or climax.
13. How Introduced and Invasive Species Alter Ecological Balance
What happens to your block when a new neighbor moves in? Something changes, right? Now think about that on an ecological scale: what happens to an environment when a new SPECIES moves in?
14. 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.
15. 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.
16. Pollution and Habitat Destruction: The Human Factors Contributing To Endangerment & Extinction
In this lesson you will learn about two ways humans contribute to species extinction. We break up habitats by building roads and clearing land, and we pollute both land and water. You will also learn about the specific terms used to describe the processes, habitat fragmentation and anthropogenic pollution.
17. What Is an Invasive Species? - Definition, List & Effects
This lesson focuses on a group of organisms called invasive species. You'll learn what makes a species invasive and see some examples of invasive species. You'll also discover why invasive species are considered a problem and explore the impacts they have on the environment, the economy and on humans.
18. Over-Exploitation: How Humans Affect Ecosystems By Decreasing Species Populations
In this lesson, you'll learn how humans overexploit or overharvest species. You will discover the primary way in which humans are responsible for overfishing. You will also learn about how this negatively impacts ecosystems.
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Other chapters within the Praxis Biology (5235): Practice & Study Guide course
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- Praxis Biology: Laboratory Equipment & Measurements
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- Praxis Biology: Chemical Reactions
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- Praxis Biology: Cellular Energy Flow
- Praxis Biology: Cell Structures and Functions
- Praxis Biology: Cellular Division
- Praxis Biology: DNA and Replication
- Praxis Biology: RNA and Gene Expression
- Praxis Biology: Mutations and Other Genetic Changes
- Praxis Biology: Biology Lab Techniques
- Praxis Biology: DNA Technology
- Praxis Biology: Genetics and Inheritance
- Praxis Biology: Human Genetics
- Praxis Biology: Species, Populations and Evolution
- Praxis Biology: Origin of Life on Earth
- Praxis Biology: Classification of Organisms
- Praxis Biology: Human Anatomy and Physiology
- Praxis Biology: Immunology
- Praxis Biology: Animal Reproduction and Development
- Praxis Biology: Plant Biology
- Praxis Biology: Plant Reproduction & Growth
- Praxis Biology: Ecosystem Ecology
- Praxis Biology: Human Impacts on the Environment
- Praxis Biology: Environment and Society
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