Login

Ch 18: Principles of Ecology: Help and Review

About This Chapter

The Principles of Ecology chapter of this College Biology Help and Review course is the simplest way to master ecology principles. This chapter uses simple and fun videos that are about five minutes long, plus lesson quizzes and a chapter exam to ensure students learn the essentials of ecology.

Who's it for?

Anyone who needs help learning or mastering college biology material will benefit from taking this course. There is no faster or easier way to learn college biology. Among those who would benefit are:

  • Students who have fallen behind in understanding factors affecting ecosystem health
  • Students who struggle with learning disabilities or learning differences, including autism and ADHD
  • Students who prefer multiple ways of learning science (visual or auditory)
  • Students who have missed class time and need to catch up
  • Students who need an efficient way to learn about the principles of ecology
  • Students who struggle to understand their teachers
  • Students who attend schools without extra science learning resources

How it works:

  • Find videos in our course that cover what you need to learn or review.
  • Press play and watch the video lesson.
  • Refer to the video transcripts to reinforce your learning.
  • Test your understanding of each lesson with short quizzes.
  • Verify you're ready by completing the Principles of Ecology chapter exam.

Why it works:

  • Study Efficiently: Skip what you know, review what you don't.
  • Retain What You Learn: Engaging animations and real-life examples make topics easy to grasp.
  • Be Ready on Test Day: Use the Principles of Ecology chapter exam to be prepared.
  • Get Extra Support: Ask our subject-matter experts any ecology question. They're here to help!
  • Study With Flexibility: Watch videos on any web-ready device.

Students will review:

In this chapter, you'll learn the answers to questions including:

  • What are ecological niches, ecosystems and habitats?
  • How do food chains and food webs work?
  • What occurs during predator/prey interactions?
  • How are symbiotic relationships classified?
  • What does carrying capacity mean?
  • How do animals and plants colonize new areas?
  • What is the effect of introduced and invasive species on ecological balance?
  • How do the carbon and nitrogen cycles work?
  • What are the different types of biomes?
  • How do fossil fuels and greenhouse gases contribute to global warming?

62 Lessons in Chapter 18: Principles of Ecology: Help and Review
The Environment, Levels of Ecology and Ecosystems

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.

Ecosystems, Habitats and Ecological Niches

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.

Food Chains, Trophic Levels and Energy Flow in an Ecosystem

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.

Interspecific Competition, Competitive Exclusion & Niche Differentiation

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.

Predator/Prey Interactions, Camouflage, Mimicry & Warning Coloration

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.

Symbiotic Relationships: Mutualism, Commensalism & Parasitism

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.

Populations: Density, Survivorship and Life Histories

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.

Carrying Capacity, Migration & Dispersion

8. 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.

Dispersal, Colonization, and Island Biogeography

9. 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.

Conservation Biology, Habitat Fragmentation, and Metapopulations

10. 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.

Ecological Succession: From Pioneer to Climax Communities

11. 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.

How Introduced and Invasive Species Alter Ecological Balance

12. 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?

Biomes: Desert, Tropical Rainforest, Savanna, Coral Reefs & More

13. Biomes: Desert, Tropical Rainforest, Savanna, Coral Reefs & More

Take a trip around the world and learn all about different biomes. Why can you only find certain plants and animals in specific places? What are the most fertile climates on Earth? Watch on to answer these and other questions.

Biomes: Tundra, Taiga, Temperate Grassland, and Coastlines

14. Biomes: Tundra, Taiga, Temperate Grassland, and Coastlines

Take a trip with us in this lesson, starting in the Pacific Ocean, traveling across California through the Central Valley and up to the peaks of the Sierra Nevada mountains. We'll learn how oceans, elevation, and people can determine which types of biomes are found in different areas and check out the Earth's most massive and oldest organisms.

Biogeochemical Cycling and the Phosphorus Cycle

15. Biogeochemical Cycling and the Phosphorus Cycle

In this video lesson, we'll take a look at how elements large and small use other elements to grow. This is achieved through cycles. We'll look at macronutrients, trace elements and the biogeochemical and phosphorous cycles.

The Nitrogen Cycle, Acid Rain and Fossil Fuels

16. The Nitrogen Cycle, Acid Rain and Fossil Fuels

Do you know the difference between nitrite and nitrate? Do you have any clue how all the nitrogen in the atmosphere becomes usable? If you can't answer these questions, then you need to watch this lesson on the nitrogen cycle.

The Carbon Cycle and Long-Term Carbon Storage

17. The Carbon Cycle and Long-Term Carbon Storage

All living organisms have a role in the carbon cycle. Do you know you understand how humans, animals and plants use carbon? This lesson will introduce you to the carbon cycle and explain how it functions on a global scale.

Fossil Fuels, Greenhouse Gases, and Global Warming

18. Fossil Fuels, Greenhouse Gases, and Global Warming

In this video lesson, you'll learn what roles fossil fuels and greenhouse gases play in global warming, as well as what life on Earth can expect due to rising carbon dioxide levels within Earth's atmosphere.

Symbiotic Relationship: Definition & Examples

19. Symbiotic Relationship: Definition & Examples

Symbiotic relationships are a special type of interaction between species. Sometimes beneficial, sometimes harmful, these relationships are essential to many organisms and ecosystems, and they provide a balance that can only be achieved by working together.

Army Ants: Facts, Types & Life Cycle

20. Army Ants: Facts, Types & Life Cycle

In this lesson, you will explore the warring world of the army ant. We'll discuss where they are found, what makes these ants different than other ants, and how their life cycle results in sedentary, roaming and active phases of their life.

Estuary: Definition, Facts, Characteristics & Examples

21. Estuary: Definition, Facts, Characteristics & Examples

Have you ever gone swimming, kayaking, or exploring in a marshy coastal area? If so, you were enjoying the natural beauty of an estuary, a place where rivers meet large bodies of water. These unique ecosystems are important, but also under threat.

What is the Biogeochemical Cycle? - Definition & Explanation

22. What is the Biogeochemical Cycle? - Definition & Explanation

Did you know that all elements are recycled over and over again on Earth? In this lesson, we'll learn about the biogeochemical cycle and explore the cycle of phosphorus as an example. Test your new knowledge at the end with a quiz.

Manganese: Facts, Uses & Benefits

23. Manganese: Facts, Uses & Benefits

From soda cans to trace amounts in your body, manganese has a number of uses and health benefits. In this lesson, you will learn about where manganese is located on the periodic table, when it was discovered, and some of its most common uses and benefits.

Acid Rain: Effects & Causes

24. Acid Rain: Effects & Causes

This lesson will focus on the environmental problem known as acid rain. It will also explore the causes and effects of acid rain, how it is measured, and what is being done to reduce it.

Batesian Mimicry: Examples & Definition

25. Batesian Mimicry: Examples & Definition

Batesian mimicry describes a relationship between two organisms - where one that is harmless looks almost exactly like one that is harmful. In this lesson, you'll learn about who discovered this relationship. We'll also explore examples of Batesian mimicry.

Chaparral Biome: Definition & Locations

26. Chaparral Biome: Definition & Locations

Our world is composed of numerous biomes. In this lesson, we will take a closer look at the chaparral biome to gain an understanding of what makes up this dynamic and unique part of our planet.

Climax Community: Definition & Example

27. Climax Community: Definition & Example

In this lesson, you will learn about ecological communities that have reached a point of equilibrium. Though rare in nature, these communities are unique because they are so well established that they exhibit very little change.

Clumped Dispersion Pattern: Definition & Explanation

28. Clumped Dispersion Pattern: Definition & Explanation

This lesson differentiates among three types of dispersion patterns, focusing specifically on clumped dispersion. You'll learn what causes clumped dispersion and explore some examples.

Denitrification: Definition & Explanation

29. Denitrification: Definition & Explanation

In this lesson, you'll learn about denitrification, its relationship to the nitrogen cycle, what's responsible for it, why it happens and what it means for humans and the environment.

Intraspecific Competition: Example & Definition

30. Intraspecific Competition: Example & Definition

How do members of the same species share resources? There's an ongoing struggle among individuals of the same species called intraspecific competition, and this competition is one way that nature controls how large a population gets.

Island Biogeography: Theory, Definition & Graph

31. Island Biogeography: Theory, Definition & Graph

In this lesson, you will learn about island biogeography, which is the species composition on an island. Because island habitats are so isolated and unique, the theory of island biogeography explains how many species can live there and why.

Metapopulation: Definition, Theory & Examples

32. Metapopulation: Definition, Theory & Examples

A metapopulation is a group of populations that are separated by space but consist of the same species. These spatially separated populations interact as individual members move from one population to another.

Trophic Levels in a Food Chain: Definition & Explanation

33. Trophic Levels in a Food Chain: Definition & Explanation

This lesson will explore the feeding relationships of organisms in an ecosystem, including food chains and food webs. The lesson will also investigate the different trophic levels of a food chain and give examples of species found at each level.

What Are Coral Reefs? - Facts & Types

34. What Are Coral Reefs? - Facts & Types

Coral reefs are some of the most complex biological communities on earth. Teeming with life, these economically and environmentally important ecosystems provide a home for many unique marine organisms.

What Is Ecology? - Definition & Explanation

35. What Is Ecology? - Definition & Explanation

From the largest animals to bacteria invisible to the human eye, the survival of any organism depends on its interaction with the environment. In this lesson you will learn the basics about ecology, the scientific study of these interactions.

What is Prey? - Definition & Examples

36. What is Prey? - Definition & Examples

What makes an organism a prey item? Can prey become predator? Prey come in all shapes and sizes, and many have special adaptations to help them survive.

Wildlife Corridors: Definition & Explanation

37. Wildlife Corridors: Definition & Explanation

The road you take to work every day is a corridor - it allows you to get from one place to another. Wildlife corridors are like roads for animals, helping them travel between the places they need to go.

Arctic Food Chain

38. Arctic Food Chain

In this lesson, we'll cover what a food chain is and what plants and animals are involved in the Arctic food chain. We'll end with the important of preserving the Arctic wildlife in the food chain.

Food Chain of a Cheetah

39. Food Chain of a Cheetah

This lesson is on the food chain of a cheetah. We'll explore how food and energy is transmitted between different species in the cheetah's home, the African Savanna.

The Food Chain of a Deciduous Forest

40. The Food Chain of a Deciduous Forest

Can you describe how the organisms of a deciduous forest interact? This lesson will show you some of their interactions, as well as offer a visual representation of how these organisms relate to one another.

The Desert Energy Pyramid

41. The Desert Energy Pyramid

This lesson is on the desert energy pyramid. In this lesson we'll cover what an energy pyramid is and how energy flows through an ecosystem, particularly the desert.

The  Food Chain of a Dolphin

42. The Food Chain of a Dolphin

This lesson explains the food chain of a dolphin. Here, we'll learn about what a food chain is and about different dolphin species. We will also study examples of food chains for different species of dolphins.

Freshwater Food Chain

43. Freshwater Food Chain

Usually when people think of aquatic animals, they think of fish, but there's so much more than just fish living in your closest river or lake! Read this lesson to learn who eats who in a freshwater food chain.

Grassland Food Chain

44. Grassland Food Chain

A grassland is a unique ecosystem with surprising diversity; there are many different types of both plants and animals. In this lesson, you'll learn about grasslands, how food chains work, and who eats who in a grassland ecosystem.

Human Food Chain: Definition & Examples

45. Human Food Chain: Definition & Examples

In this lesson, you will learn what a food chain is and what composes one. You will also learn about different food chains that humans fit into, seeing many different examples.

Industrial Food Chain

46. Industrial Food Chain

In this lesson, we'll learn what a traditional food chain is and then apply it to the human food industry. We'll also go over some criticism of the current industrial food chain.

The Food Chain of a Lion

47. The Food Chain of a Lion

This lesson is about the food chain of a lion. Here, we'll examine where lions live and some facts about these animals. We will also review what food chains are and learn what the specific food chain for a lion looks like.

Ocean Energy Pyramid

48. Ocean Energy Pyramid

What do you know about energy pyramids and how they relate to the the ocean ecosystem? In this lesson, you will learn what an energy pyramid is as well as what the energy pyramid of the ocean looks like.

Ocean Food Chain

49. Ocean Food Chain

This lesson is on ocean food chains. In this lesson, we'll go over what a food chain is and what the different oceans are. Then, we'll get into two specific food chains in the Arctic and Pacific Ocean.

Owl Food Chain

50. Owl Food Chain

This lesson is on the owl food chain. In this lesson, we'll go over what a food chain is and different types of owls. We'll also dig into specific food chains for a few different species of owls.

Polar Bear Food Chain

51. Polar Bear Food Chain

This lesson is on the food chain of a polar bear. In this lesson, we will cover some facts about polar bears and the ecosystem they live in, as well as what a food chain is and what the polar bear's food chain looks like.

The Pond Food Chain

52. The Pond Food Chain

What eats what in a pond? All ponds are unique and may have different organisms living in them. This lesson describes the basic structure of a pond food chain and how that structure applies to any pond you may encounter.

Prairie Food Chains & Webs

53. Prairie Food Chains & Webs

Do you know how organisms of the prairie interact with one another? In this lesson, you will learn about these interactions. You will also get to view a visual representation of these interactions via a food web.

Quaternary Consumers: Definition & Types

54. Quaternary Consumers: Definition & Types

This lesson introduces and explains the ecological concept of a quaternary consumer. It discusses which organisms act as quaternary consumers and how this role can change within the environment. A lesson summary and brief quiz are included.

Rainforest Food Chains

55. Rainforest Food Chains

This lesson is on rainforest food chains. In this lesson, we'll go over what a rainforest is and where they are, as well as some food chain basics. Then, we'll get into two specific food chains in the Amazon Rainforest.

Respiration in the Water Cycle

56. Respiration in the Water Cycle

This lesson introduces how the process of cellular respiration fits in the water cycle by using explanations of the water cycle, respiration, and photosynthesis. The quiz following the lesson will test how well you understand the place of respiration within the water cycle.

The Food Chain of a Tiger

57. The Food Chain of a Tiger

This lesson explores the food chain of a tiger. We'll learn what a food chain is and what different types of tigers live in the world. Then, we'll cover two specific food chains for different species of tigers.

Wetland Food Chains

58. Wetland Food Chains

In this lesson, we'll cover what a wetland is and where you can find them. We'll also look at food chains and go over two specific examples of wetland food chains and why they are important.

Wolf Food Chain

59. Wolf Food Chain

You might know that the wolf is a top predator. But do you know exactly what a wolf eats? In this lesson, we'll review the definition of 'food chain' and describe specifically the specific food chains for two species of wolves.

Chordata Germ Layers

60. Chordata Germ Layers

Members of the phylum Chordata have three main germ cell layers, each with its own unique role in development. In this lesson, we'll discuss the structure, function, and derivation of the germ cell layers of chordates.

Abiotic Synthesis & the Origin of Life

61. Abiotic Synthesis & the Origin of Life

Abiotic synthesis means making compounds using non-living molecules. It's possible that organic molecules formed before life began and built up to make the first cells. Let's explore this theory and its hallmark experiment.

Pink River Dolphins: Facts & Habitat

62. Pink River Dolphins: Facts & Habitat

The pink river dolphin is a freshwater dolphin species found in South America. Their vivid pink color is only one of many cool things about them. Keep reading to learn what makes this species so unique.

Earning College Credit

Did you know… We have over 95 college courses that prepare you to earn credit by exam that is accepted by over 2,000 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.

Support