chapter: ecology table of contents section 3: energy through theenergy through the ecosystem section...

Chapter: Ecology

Table of ContentsTable of Contents

Section 3: Energy Through the Ecosystem

Section 1: What is an ecosystem?

Section 2: Relationships Among Living Things

A. Organizing Ecosystems

1. When ecologists study living things, they usually start by studying the small groups in biosphere.

2. To separate the biosphere into smaller systems that are easier to study, ecologists find it helpful to organize living things into groups.

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B. Groups of Organisms1. A population is a group of the same type of

organisms living in the same place at the same time.

2. Some populations that you might find in a coral reef ecosystem are sponges, algae, sharks, and coral.

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B. Groups of Populations3. All of the

populations that live in an area make up a community (kuh MYEW nuh tee).

4. The members of a community depend on each other for food, shelter, and other needs.

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C. Characteristics and density

of Populations

1. Ecologists study the characteristics of populations.

They study the size of the population, where its members live, and how the population is able to stay alive.

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C. Characteristics and density

of Populations

2. Population density is the size of the population compared to its area.

3. For instance, if 100 dandelions are growing in a field that is one square kilometer in size, then the population density is 100 dandelions per square kilometer.

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D. Studying Populations1. Monarch butterflies travel to warm climates

for the winter. They return to the same place year after year. This seasonal travel is called migration.

2. To study migrating monarch butterflies, an ecologist catches a butterfly and attaches a tag to one of its wings.

3. Later, someone else who catches the same butterfly can use the tag to figure out how far the butterfly has flown.

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D. Studying Populations4. Information from many butterflies can be combined to build a picture of the monarch's migration.

5. Similar techniques are used to study populations of birds, wolves, and other animals that travel long distances.

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E. Limits to Populations

1. Populations cannot grow larger and larger forever. Resources such as food, water, and living space would eventually run out.

2. The things that limit the size of a population, such as the amount of rainfall or food, are called limiting factors.

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E. Limits to Populations3. In a stream ecosystem, an abiotic limiting

factor might be a lack of rain.

4. If the stream dries up because of lack of rain, the population of mosquitoes might not have place to breed. The mosquitoes are a biotic factor.

5. If the population of mosquitoes goes down, then the frog population might not have enough food. This would limit the size of the frog population.

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F. Interactions in Communities

1. One of the most common ways organisms interact in a community is by being food for another organism, as shown in the picture.

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2. Organisms will compete for any resource that is in limited supply.

F. Interactions in Communities

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4. Space, water, sunlight, and shelter are all resources that may be limited in a particular ecosystem.

3.The greater the population size of an area, the greater the competition for resources such as food.

G. Eat or Be Eaten1. A falcon is a predator (PRE duh tur), which

means it captures and eats other animals. The animals the falcon catches and eats are its prey.

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2. The act of one organism feeding on another is called predation (pre DAY shun).

H. Organisms That Live Together

1. There are other types of relationships among organisms.

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2. In one type of interaction, both organisms in the relationship benefit. For example, an african tickbird gets its food by eating insects off the skin of zebras.

H. Organisms That Live Together

3. The tick birds gets foods, and the zebra gets rid of harmful insects.

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http://www.youtube.com/watch?v=2D1mu9WYBNw

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4. In another type of relationship, only one organism benefits. For example, a bird builds a nest in a tree.

5. The bird gets shelter from the tree, but the tree is not harmed.

H. Organisms That Live Together

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6. In still another relationship, one organism is helped while the other is harmed. Have you ever been bitten by a mosquito? That's a firsthand experience of this type of relationship.

I. Where and How Organisms Live

1. The role of an organism in an ecosystem is called the organism's niche (NICH). For example, an aquarium may contain fish, snails, algae, and bacteria.

2. Each of these organisms has a role in the aquarium. The snails eat algae to help keep the glass clear for light to get in.

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I. Where and How Organisms Live

3. The algae provide food for the snails and fish, and provide oxygen for the system

4. The niche of the fish is to provide nutrients to the ecosystem through its waste products.

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I. Where and How Organisms Live

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5. The place where an organisms lives is called its habitat (HA buh tat).

The habitat of a catfish is the muddybottom of a lake or pond.The habitat of penguinIs the icy waters of theAntartic.

I. Where and How Organisms Live

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6. Different species of organisms often live in the same habitat. Resources, such as food, living space, and shelter, are shared among all the species living in a habitat.

I. Where and How Organisms Live

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7. For example, Spiders feed on beetles and other insects. Caterpillars eat leaves. Fruit flies feed on apples. Birds eat spiders. Caterpillars or flies. Each species has a different niche within the same habitat.

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A. flock of birds that includes pigeons, sparrows, and doves B. forest of trees and all the birds that live in themC. group of elephants in Africa and another group in IndiaD. group of gray squirrels that live in a park together

Which represents a population?

Question 1

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Question 2What type of information would you need to collect concerning the monarch butterflypopulation in order to prepare a map like this one showing the migration of monarchs?

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A. How long butterflies liveB. what foods butterflies eatC. when butterflies fly through certain areas D. when butterflies lay their eggs

Section CheckSection Check

Question 3

What is the difference between an organism’s niche and its habitat?

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