HUMANS IN THE BIOSPHERE

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A CHANGING LANDSCAPE

OBJECTIVES: 6.1

Describe human activities that can affect the biosphere.

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_____ is an island.

All of the organisms (including us) that live on earth share a _______ resource base and depend on it for their long-term survival.

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Among human activities that affect the biosphere are ______ and gathering, agriculture, _____, and urban development.

Hunters and gatherers4

By the end of the last ice age – about 11,000 yrs ago – humans began to practice ______ (agriculture).

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In the 19th and 20th centuries, advances in science and technology set the stage for a remarkable change in agriculture.

Ex. ________, machinery, new crops with higher ____, monoculture, chemical fertilizers.

Monoculture is where large fields are planted with a single variety year after year.

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______ revolution is the development of highly productive crop strains and the use of modern agricultural techniques to increase yields of food crops.

Human society and its impact on the biosphere were transformed by the _______ Revolution, which added machines and factories to civilization during the 1800s.

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Certain kinds of ________ processes pollute air , water, and soil.

Dense _____ communities produce wastes that must be disposed of.

________ growth consumes farmland and natural habitats, and can place additional stress on plant an animal populations and on the biosphere’s life-support systems.

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RENEWABLE AND NONRENEWABLE RESOURCES

OBJECTIVES: 6.2

Explain how environmental resources are classified.

Identify the characteristics of sustainable development.

Describe how human activities affect land, air, and water resources.

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There are two types of environmental goods and services:

1. ________ resources: can be regenerated if they are alive or can be replenished by biochemical cycles.

________ resources may not be unlimited (ex. Water can be made unusable by pollution).

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2. ________ resources: cannot be replenished by natural processes.

Ex. Coal, _____, and natural gas

_________ development is a way of using natural resources without depleting them and of providing for human needs without causing long term environmental harm.

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Human activities can affect the quality and supply of renewable resources such as land, _____, ________, air, and freshwater.

_____ _____is the wearing away of the surface soil by water and wind.

____________ in dry climates, is caused by a combination of farming, overgrazing, and drought.

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__________ is the loss of forest.

We are harvesting ____ faster than they can be replaced by reproduction.

__________ is the raising of aquatic animals for human consumption.

____ = smoke + fog

A pollutant is a _________ material that can enter the biosphere through the land, air, or water.

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____ rain – rain that has a pH level less than 7.

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BIODIVERSITY

OBJECTIVES: 6.3

Define biodiversity and explain its value.

Identify current threats to biodiversity.

Describe the goal of conservation biology.

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________ is the sum total of the genetically based variety of all organisms in the biosphere.

Ecosystem diversity includes the variety of ________, communities, and ecological processes in the living world.

______ diversity refers to the sum total of all the different forms of genetic information carried by all the organisms living on Earth today

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Biodiversity provides us with foods, industrial products, and medicines (painkillers, antibiotics, heart drugs antidepressants, and anticancer drugs).

Biodiversity can be reduced by _____ activity (altering habitats, hunting species to extinction, introducing toxic compounds into food webs, and introducing foreign species to new environments).

Snake head fish introduced into the U.S. (Africa, Asia)

Kudzu introduced in the southeast (Asia)

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Burmese python introduced to the Everglades.

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Human activities may cause species to go _____.

_______ occurs when a species disappears form all or part of it range. (when the last individual of a species dies).

An ________ species is one whose numbers are declining in a way that it places it in danger of extinction.

Habitat __________ is the process of splitting ecosystems in pieces.

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The U.S. protects endangered species.

The Convention on International Trade in Endangered Species (______) bans international trade in endangered species.

____ was a widely used pesticide.

When it was sprayed it ran off into the waters.

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DDT has two properties that makes it hazardous.

1. _________ – can not be broken down in nature (by bacteria, plants, etc).

2. when organism gets DDT it is not eliminated from the body (biological magnification).

_______ magnification increases in each trophic level, it affects the entire food chain or web.

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______ species – species that are introduced either intentionally or unintentionally.

They reproduce rapidly because they lack _______ and parasites that control their population in their native land.

Zebra mussel Leafy spurge

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_________ – the wise management of natural resources.

Today, we try to conserve the ________ as well as the species.

Protecting ecosystems will ensure that the natural _______ and the interactions of many different species are preserved at the same time

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CHARTING THE COURSE FOR THE FUTURE

OBJECTIVE: 6.4

Describe two types of global change that are of concern to biologist.

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_____ (O3) layer – is about 20 to 50 kilometers above the Earth’s surface.

Some evidence indicates that the ozone layer is being depleted (hole over Antarctica) by _____ (chlorofluorocarbons, now banned).

_______ warming – the increase in the average temperature of the biosphere (polar caps melting) caused by greenhouse gases.

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