Science and Geo 6 std Unit 0 -...

Ecosystems and the Environment

1● Copy and complete the table.

name American Crocodile

vertebrateskin co veringreproduction

sense organsmovement

eating habitshabitat

arthropod – reptilescales – fur

oviparous – viviparouseyes – tentacles

wings – legscarnivore – omnivoreaquatic – terrestrial

Observing and Recording

4

Science and Geo 6 std Unit 1.qxd 2/11/09 3:27 PM Page 4

Reporting● Talk about the reading.

– What type of text is this: biograph y,advertisement orinformative?

– What is the land lik e?– What type of animals

are there?– Would you lik e to visit

the Park? Why / Wh ynot?

● Convince your friendsabout the importance ofpreserving nature.

Learn about the UnitEvery living species lives in a par ticular habitat.Ducks live near w ater; camels live in deser ts.There are links betw een living things. For example, deer eat grass; wolves eat deer .People are also living things. Their actions impact onother living things and cause global changes.

In this unit, we are going to study:● Ecosystems and their components● Links betw een living things● The environment● Environmental problems and solutions

Key SkillsExpressing facts:Trees provide food...; ...the parasite harms the host;living things interact with...

Talking about possibility:Two species may need...; fishing may cause...; others may disappear...

Describing a condition:If one species becomes extinct...; What will happen if the mice...?; If we use lesselectricity...

Everglades National ParkEverglades National Park is a national park in the USA that contains 25%of the original Everglades marshlands of southwestern Florida. The park was created toprotect this fragile, subtropicalecosystem of slow-moving rivers.

Thirty-six threatened or endangered species can be found inthe Everglades, including the Floridapanther, the American crocodile and the West Indian manatee. The park is one of themost important breeding grounds for wading birds in NorthAmerica.

In spite of conservation efforts the ecosystems in EvergladesNational Park have suffered significantly from human activity.

5


1. What is an ecosystem?

An ecosystem consists of living things in a specific environment and the relationshipsbetween them and their habitat.

For example, a lake is an ecosystem. It is madeup of the: ● water ● lake bottom ● shores ● plants ● animals ● algae An ecosystem can be as small as a pond or as large as the Amazon rainforest.

2. The components of an ecosystem

Ecosystems ha ve two components:● Living things: all the plant life

in an ecosystem is called the vegetation. All the animal life in an ecosystem is calledthe fauna. Fungi, bacteria and algae are alsopresent.

● Environment: everything that affects livingthings. Soil, climate, water and light are par tof the en vironment.

1

Ecosystems

Components of an ecosystem1

Plants modify the environment. Plant roots gradually breakdown rocks.

2

3. Relationships within an ecosystem

Living things interact with each other and with their en vironment. The characteristics of the en vironment deter mine what living thingsexist in an ecosystem. F or example, deser tsare dry, so only plants and animals that don’ tneed much w ater grow there. Only plants withsmall roots grow in rock y areas.

Living things can modify the en vironment. For example, plants can break down rocks,and change them into fer tile soil. 2

ecosystem

living things

physical environment

roots

rock

6


Complete the definitions. Match.

a. An ecosystem is made up of...

b. The environment consists of...

1. light, water, climate, soil.

2. living things and their en vironment.

Match to create examples.

a. Living things change their en vironment,for example,...

b. The environment deter mines whatliving things exist there, for example,...

1. plants break down rocks.

2. trees only grow in areas with w ater.

What type of ecosystem is this?3

2

1

Ecosystems are made up of a community of living things and their physical environment.The environment affects living things, and livingthings can change their environment.

Forests and climates. A Forest B Grassland C Desert3

4. Ecosystems

There are man y different ecosystems on Ear th.Ecosystems can be ter restrial or aquatic.Typical ter restrial ecosystems are:● Forests. Trees are the most impor tant living

things in a forest. T rees pro vide food andshelter for man y animals.

● Grasslands. Tall grass is the mostcharacteristic feature. Large animals,such as zebras, gazelles or antelopes,graze here; that is, they eat the grass.

● Deserts. Precipitation is ver y scarce here,so vegetation and fauna are also scarce.

Aquatic ecosystems can be classified into two groups:● Freshwater ecosystems are found in river s

and lakes.● Saltwater ecosystems are found in the

ocean: for example, a coral reef.

3

B CA

Summary

7

1

A C T I V I T I E S


Secondary consumers. Cheetahs feed on gazelles and other animals that eat grass.

1

Example of a food chain. The arrows link the food to theliving thing that eats it.

2

Relationships between Living Things

Secondary consumerladder snake

Primary consumerfield mouse

Producerwheat

▼▼

▼

▼

▼

1. Living things and food

The relationships betw een the living things in an ecosystem var y. One of the mostimportant relationships in volves food. Living things can be classified according to how the y obtain food:● Producers make their own food. Plants and

algae that need sunlight for photosynthesisare the most common producer s.

● Primary consumers are animals that feed onproducers. For example, herbivores,like deer or zebras, eat plants and algae.

● Secondary consumers are animals that feedon primar y consumer s. For example,predators like eagles, lions or wolves belongto this group.

Decomposers are living things that feed on theremains of other living things:

– feces – animal cor pses – leaves and branches

Most decomposer s are fungi and bacteria.

1

2. Food chains

Food chains show how food passes throughdifferent living things in an ecosystem.

Food chains usually consist of a producer ,a primary consumer and a secondar yconsumer.

Food chains are longer when one secondar yconsumer becomes food for another secondar y consumer. This secondar y consumeris also called a ter tiary consumer.

Food chains are not the only w ays in which living things relate to each other .

2

8


Mutualism. These birds eat parasites, so both the waterbuffalo and the bird benefit.

3. Parasitism, mutualism and competition

Parasitism, mutualism and competition arethree other w ays living things relate to eachother.● Parasitism. This relationship is har mful

for the host. One living thing , a parasite, livesoff another, its host. As the parasite feeds,it harms the host. F or example, the mistletoethat grows on trees feeds on sap.

● Mutualism. This relationship is beneficial for two living things. F or example, somesmall African birds feed on parasitic insects.These insects feed on herbivores. When thebirds feed on the insects, they free theherbivores from the parasites.

● Competition. This relationship is har mful for all species. F or example, several speciesmay need the same resource: food, refuge,or light. T rees in forests compete forsunlight. Some receive more light and growtall. Other s receive less light and die.

4

3

Parasitism. Mistletoe takes nutrients from trees.3

Complete: If a living thing..., it is a...

a. makes its own food b. feeds on the remains of living things c. feeds on a producer

1. producer 2. primary consumer 3. decomposer

Describe this food chain with a diagram. Use diagram as a model.

Define the relationship betw een mosquitoes and human beings with one word.3

lizardgrasshoppergrass

22

1

Living things can be divided into producers,consumers and decomposers. Relationshipsamong living things can be represented by foodchains. Other relationships are parasitism,mutualism and competition.

Summary

4

9

1

A C T I V I T I E S


1. What is the environment?

The environment is all the circumstances, living thingsand habitats with which a living thing interacts.

Human beings live almost e verywhere on Ear th, andeverything in their en vironment affects them.Environment refer s to:● living things● physical features ● soil● water● air ● climate

In other words, nature and all the ecosystems on Ear thmake up the en vironment.

Human beings affect and are affected b y theenvironment. Agriculture, construction, hunting and other activities can change the en vironment.

Human impact on the en vironment has been great. For example, the population of the wor ld has increasedsignificantly since the nineteenth centur y. Fossil fuels,mainly coal and oil, are used more and more. As a result, many harmful changes ha ve occurred.

1

2. Pollution

The contamination of air , soil or w ater with har mfulsubstances is called pollution.● Air is polluted when the combustion of oil or coal

produces smok e.● Soil is polluted when har mful substances are dumped

on it. F or example, the insecticides used in agriculture remain in the soil and pollute it.

● Rivers and oceans are polluted when urban and industrial w astes are dumped in them.

Rainwater can also pollute river s and oceans. Rain carries polluted soil and air , and deposits harmful substances into river s and oceans.

Pollution changes the ph ysical en vironment and affectsliving things. Consequently , when people pollute,they change the ecosystems.

2

Environmental Problems

Soil pollution. Planes spray insecticides over large areas.

2

● insecticide: chemical substance used to kill insects.It can be harmful to crops.

Vocabulary

Rabbit environment. It consists of everythingthat affects the rabbit: physical environmentand other living things.

1

10


3. Global warming

Carbon dioxide in the atmosphere acts lik e a blank et andmaintains heat on the Ear th. Thanks to this heat, life onEarth is possible. How ever, the amount of carbon dioxidein the atmosphere has increased in recent decadesbecause more fossil fuels, such as coal and oil, are used.

Scientists belie ve that the Ear th’s temperature isincreasing because the atmosphere contains too man yof these gases. The atmosphere does not let heatescape.

The gradual increase in global temperatures is calledglobal warming. The atmosphere, like the glass in a greenhouse, lets light in, but does not let heat out.This is called the greenhouse effect. Global w armingaffects man y ecosystems. 3

4. Extinction

Pollution, global warming, deforestation, illegal huntingand fishing ma y cause a species to become extinct.In fact, many animal and plant species ha ve disappearedforever.

Nowadays many species are endangered, and some ma yalso become extinct. All species are par t of a food chain:they are dependent on each other . Consequently , if onespecies becomes extinct, others may also disappear . 4

Endangered animals. A panda bearB gray whale

4

A

B

The greenhouse effect. Carbon dioxide and gases trap heat in the atmosphere.

3

Complete: The environment consists of...

True or false: If one species disappears, others may also disappear.

Describe diagram . Complete the sentences.a. Carbon dioxide and... b. These gases k eep heat... c. The atmosphere gets...

33

2

1

The environment of a living thing consists of its physicalenvironment and all the living things it interacts with.Pollution, global warming and the extinction of somespecies are environmental problems.

Summary

Sunlight, solar energy

Heat from the Earth

The Earth

Atmosphere,carbon dioxide and other gases

11

1

A C T I V I T I E S


1. Environmental awareness

Around sixty year s ago, environmentalistsbegan to realize that the en vironment was in danger. There w ere fewer wildlife areas and many more endangered species.

Today many people belong to en vironmentalorganizations. The y try to protect the environment. In some countries,environmental political par ties ha ve also appeared. 1

2. Wildlife preserves

Wildlife preserves are areas where laws protectthe environment. The vegetation and fauna in these preserves are protected.

Preserves can be established b y different levels of go vernment, for example, national or state.

Governments can protect the en vironment in several ways. For example, they can protect an area.

Building, cutting down trees or other activitiesthat harm the en vironment can be prohibited. 2

3. Endangered species

Endangered animals need special protection to sur vive. Laws can protect animal habitatsfrom destr uction or prohibit hunting duringbreeding season.

Some species are already so endangered that more drastic measures are necessar y. Wild animals ma y also be k ept in zoos or special places so the y can reproduce in captivity. 3

Environmental Protection

Yellowstone National Park is home to a large variety of wildlife.

2

Ecologists from WWF/Adena use seeds from wild plants to provide vegetation in areas with few plants.

1

Protected species. American lynx can reproduce incaptivity. This may help them survive.

3

12


Environmental awareness grew in the mid-twentieth century. Governments createdwildlife preserves, protected endangeredspecies and controlled pollution.

4. Fighting pollution

Pollution can be fought at se veral levels:● Individual. We can reduce pollution if w e use

less electricity because the pow er stationwill use less fuel to produce it.Everyone should recycle trash. F or example,classify trash for recycling , like glass,packaging or paper . Then deposit each typein the appropriate dumpster .

● National. Countries can pass la ws to limitindustrial pollution. F or example: – create water treatment plants for se wage

and industrial w aste – limit and monitor smok e produced

by industries and home heating units

Governments should also encourage the useof nonpolluting sources of energ y, such assolar or wind pow er.

● International. Treaties can reduce globalwarming. The countries that signed the Kyoto Protocol are reducing the amount of carbon dioxide the y release into theatmosphere.

4

Wind is a nonpolluting source of energy. Wind energy canproduce electricity.

4

● international treaty: an agreement between two or more countries

Vocabulary

What environmental organizations do you know?

Which actions can protect endangered animal species?a. Put animals in zoos. b. Prohibit hunting . c. Protect animal habitats. d. All of these.

If we save electricity, how will we reduce pollution?

How are the signer s of the K yoto Protocol fighting pollution?4

3

2

1

Summary

13

1

A C T I V I T I E S


A C T I V I T I E S

04. Identify the relationship: mutualism,parasitism or competition.

When... the relationship is called...

a. neither species benefits,

b. both species benefit,

c. one species benefits, and the other isharmed,

05. What may happen if one species becomes extinct?

06. How can we reduce pollution? Give threeexamples: At the...level, we should...

a. individual b. national c. international

07. Which relationship is described here?

Cuckoo birds lay their eggs in the nests of other bird species. When the cuckoochicks are born, they push other eggs orchicks out of the nest. The parent birds“adopt” the cuckoo chicks and feed them.

08. How can air and water pollution from alarge city reach the ocean? Draw a diagram.

09. Study the food chain, page 8,and answer.

a. What will happen if the mice disappear?

b. What will happen if the snak es disappear?

10. Debate: Environmentalism stops progress.Give examples for and against.

1. Match each concept with the examples.

1. ecosystem 2. aquatic ecosystem3. terrestrial ecosystem

a. freshwater, saltwater

b. forests, prairies, deser ts

c. living things + ph ysical en vironment

Example: An ecosystem is made up of...

2. Complete and describe this food chain.

3. Complete the definitions.

a. Producers are living things that

b. Primary consumer s are animals that

c. Decomposer s are living things that

blackbird

snail

grass

UNDERSTAND

APPLY

FIGURE IT OUT

14


Draw a Food Web

Procedure

Many different food chains can exist in an ecosystem.

When se veral foods are interconnected,a food web is for med. Food webs occur when the same living thing appear s in morethan one food chain.

This table shows the connections among the eating habits of living things in African grasslands.

The arrows on the food w eb below indicatethe connections among some of these livingthings.

Do it yourself

Copy and complete the food w eb. Draw the elephant, giraffe and trees, as well as ar rows torepresent the connections indicated in the table.

Living thing Feeds on... Serves as foodfor...

grass

trees

water buffalo

water buffalo,zebra, gnu, gazelle

gazelle, giraffe,elephant

lion

zebra lion, hyena

gnu lion, hyena

gazelle lion, hyena

giraffe

elephant

hyena

lion

lion

grass

grass

grass

grass, trees

trees

trees

zebra, gnu, gazelle

water buffalo,zebra, gnu,

gazelle, giraffe

hyena

waterbuffalo

zebra gnu gazelle

grass

lion

I CAN DO IT

15


Now I Know

1. Copy and complete the word map.

are made up of deteriorate because of

2. Describe this ecosystem, an aquarium.

● This ecosystem is made up of and

● The living things are divided into and .

● This ecosystem ma y deteriorate if .

● This ecosystem is protected b y and .

Ecosystems

are protected by

are divided intothe fightagainst

pollution

the environment

pollution

decomposers

Check what you know

16

3. Complete the chart.

ECOSYSTEMSTerrestrial ecosystems

FreshwaterGrasslandThey are found

in the ocean, like coral reefs


Butterfly GardeningButterfly gardening has become one of the most popular hobbies today. A butterfly garden is an easy way to see more butterflies and contribute to their conservation.

A butterfly garden is easy to make. First, choose plants thatcaterpillars eat and adult butterflies feed on. Plant your garden in a sunny location sheltered from the wind.

Remember that butterflies drink water, too. They like todrink from mud puddles to obtain salts and minerals. Finally, don't use pesticides in your garden!

Where should you plant your garden?

Why do butterflies like to drink from mud puddles?

A Report: A Wildlife Preserve

Write about a national par k, wildlife preser ve or other protected areathat you know. Imagine that someone will use your repor t to find out the most impor tant features of the area.

1. Find information.

● Use books, encyclopedias, Internet, tourist literature,...

2. Select and organize the information. Include these sections:● Essential facts: name, location and type of preser ve● How to get there● Description of the landscape● Typical vegetation and fauna● Points of interest or itineraries

3. Write and illustrate the report.

● Clearly identify each point in section 2 with a title.● Write clear, shor t sentences.● Include photos, newspaper ar ticles or brochures.

4. Present your report.

● Prepare a co ver and a title.

Citizenship

Find out and write

17


Science and Geo 6 std Unit 0 -...

Documents

Transcript of Science and Geo 6 std Unit 0 -...