Interactions within Ecosystems Science Test

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Science Test Study Guide

Wednesday May 22g 2013

Part A-

Identify Living and Non-Living Elements in an Ecosystem & The Organization of Life Review the information sheet as well as the Matching Quiz for New Vocabulary (Multiple Choices & Short Answers)

Part B

Food Chains and Food Webs Review information sheets and questions (Short Answers)

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Part C-

Pesticides: Poisons in the Food Chain Review information and questions (Short Answers)

Part D-

Technology and our Environment (Long Answer)

Grade 7 Science and Technology Strand 1: Interactions in the Environment

Identity Living and Non-living Elements in an Ecosystem (page 8) What is an Ecozone? An ecozone is a geographic area which shares common living and non-living elements. The living elements are plants, animals and people. The non-living elements are air, water, soil and rocks. Ontario has three ecozones: Hudson Plains, Boreal Shield, Mixedwood Plains. o

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What is an Ecosystem? An ecosystem is a geographic area where plants, animals, people, air, water, soil and rocks interact as a system. Interact means the way in which plants, animals and people use living and non-living elements to survive. The Living (Biotic) Elements Plants include trees, shrubs, flowers, grasses and mosses. Living things like algae (e.g., seaweed) and fungi (e.g., mushrooms) do not belong to the plant family. Animals can be divided into two groups: vertebrates (animals with backbones) and invertebrates (animals without a backbone). All animals eat things that have been alive. People are social animals that choose to live in family groups. People have changed the environment to suit their needs.

Teacher led discussion

The Non-living (Abiotic) Elements Air is a combination of different gases like nitrogen (78%) and oxygen (21%). Animals and people breathe air to obtain oxygen to stay alive. Plants need carbon dioxide gas to stay alive. Water is a combination of hydrogen and oxygen. Water can be found in three different states: liquid, solid (ice) and gas (water vapour). The bodies of many living things are 50 to 90 percent water. Soils are a combination of biotic and abiotic material. The biotic material is living burrowing animals (e.g., earthworms) and decaying plant and animal life. The abiotic material is sand, silt, clay and minerals. Rocks are a combination of minerals and other substances like cooling lava or the skeletons of dead marine animals. A terrarium-aquarium A terrarium-aquarium is an ecosystem in a watertight container that has two distinct sections; a terrarium that consists of a small indoor garden, and an aquarium that consists of a small body of water. The terrarium-aquarium ecosystem is a place where plants, animals, air, water, soil and rocks interact as a system. A Few Human-made Features Within a Terrarium-aquarium Use the biggest rectangular container that will fit in your classroom. A ten-gallon tank is the minimum size. Place about one centimetre of crushed charcoal at the bottom of the container. Use a filter to keep the water clear. Select a filter that will allow the creation of a tiny waterfall. The water path must be made of rock with a waterproof layer underneath. The water path will lead directly to the aquarium section.

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Or 7 ON-SCl—TranspQy1’

Activity 2 Ch

Grade 7 Science and Technology Strand 1: Interactions in the Environment Identify Living and Non-living Elements in an Ecosystem Teacher’s Answers (page 10)

Instructions: Read for understanding the facts on page 8 then complete all sections on this page.

1. What is an ecozone?

An ecozone is a geographic area which shares common living and non-living elements.

5. What are the four n-bving (éotic) elements? a)Aw b) WaLer c)Soil 4 locks -léving element? 6. Why is soil beth a living Almost all soil wks contain lii and non-li ving elements often the living examples are too small to be seen -

2. What is an ecosystem? An ecosystem is a geographic area where plants,

7. In the spaces below, label or draw appropriately.

animals, people, air, water, soil and rocks interact as a system.

a) What are the two major gases in air?

Nitrogen (73%).

Oxygen (2196)

b) Draw three diagrams that represent the three states of water in the spaces below.

3. What does interact mean? Interact means the way in which pIaats animals

and people use living and noa.&ving elements to survive. 4. What are the living elements (bäic)? Law one example of the living elements that can be seen in a park with trees and a pond. Dr3W a plant(s) toun4 li a park a) A few examples of plants are:

Treet sbr’u)c fiowert aracces

c) Draw a diagram of biotic soil elements.

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b) A few examples of park animals are:

Draw an animal(s) found in a park

$4L racoon.

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worm corrm

What are the abiotic soil elements? Ablotk so ekeflt(

Grasshopper c) An example of social activity in a park:

A nature hike t)irouah a i,ark

Draw a social

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d) Rocks are a combination of:

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Cealina lava. etc.

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The Organization of Life As you have seen, polar bears can tolerate a wide range of environmental conditions. They survive the bitter cold and fierce winds of an Arctic winter, and the heat of the summer. They survive on land, on ice, in fresh water, and in the cold salt water of Hudson Bay. Bears see well enough to hunt in the dark of northern winter, and the almost perpetual day of northern summer. Few animals are adapted to so many different conditions or factors. The changes in temperature, the changes in the amount of sunlight, the strength and variation of the wind, the amount of rain or snowfall, and the presence of salt or fresh water are all abiotic factors of the polar bear’s environment. Abiotic factors are the nonliving, physical factors of an environment. There are other factors that affect the polar bear. If seals move to new area, the bears must also move. If there are fewer fish in the a bay, there will be fewer seals, and so the bears will go hungry. Effects such as these, caused by other living things, are the biotic factors of the environment.

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Organism An organ sm is a singe liv ng thing Ecologists may study feed ng, da ly movements, or reproduction of the p0 ar bea to help them understand the ecological niche of the organism in its ecosystem

Organizing Relationships No organism lives alone, not even the solitary polar bear. All organisms have relationships with other living things, as polar bears do with seals, fish, and people. They must also deal with the abiotic factors in their environment. Ecologists organize all of these relationships among organisms and their environment to help study the interactions. They do this by using terms to describe systems of living things, starting with the individual living thing (an organism) and progressing to the largest system, which includes every living thing on Earth (the biosphere), as shown in Figure 1. Ecologists use the term “ecosystem” to describe a wide range of systems. Some are large and some are very small. For example, the ice-floe ecosystem of Hudson Bay is very large. The ecosystem is made up of a community that includes populations of large organisms such as polar bears and seals, and also many populations of small organisms such as algae and bacteria. However, we can also speak of a temporary spring pond as an ecosystem, with a community made up of populations of tiny organisms (see Table 1). Small ecosystems can also exist within Table 1: Three Ecosystems larger ecosystems. For example, the Ecosystem Some populations in the ecosystem inside a rotting log is part of the community larger ecosystem of the forest. ce-floe system polar bears, bearded seals, Biomes are usually large and contain of Hudson Bay ringed seals, herring, krill, many ecosystems. The boreal forest biome algae stretches from the Atlantic coast through raccoons, wood frogs, central Canada and north of the prairies to small pond mosquitoes, dragonflies, the western mountains. This biome includes fairy shrimp, algae many coniferous forests, and also the abandoned city cats, mice, ants, chickadees, lot ecosystems in their clearings, lakes, streams, crab grass, dandelions and rivers. 258

Unit 5

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Understanding Concepts

0 APopulation population is the number of organisms of the same species living in an ecosystem, Ecologists might study the effects of an increasing population of polar bears on the ice-floe ecosystem.

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Community A community is all of the populatons of organisms within an ecosystem. Ecologists might study the effects on the community when one of the species becomes extinct.

1. Explain the following terms in your own words: population, community, ecosystem, biome, and biosphere. 2 Table I shows some of the populations in the community that j make up a pond ecosystem. Create a list of abiotic factors that would affect the organisms in that ecosystem. 3. In Table 1, the community of organisms that might be present in the ecosystem of an abandoned city lot is not complete. (a) What other organisms might be present in the lot either permanently or temporarily? (b List the biotic and abiotic factors that mi9ht affect the organisms in the abandoned lot ecosystem. T,;__

cosystem An ecosystem is a system of living things that interact with each other and ith the physical world. An ecologist might study how changes in snowfall affect the community that lives in the ce-floe ecosystem.

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A biome is a collection of related ecosystems. An ecologist might study how climate change affects the ecosystems of the Arctic biome.

sign Challenge • Biosphere The biosphere is all of the biomes, all of the ecosystems on Earth, from The poles to the equator, from the atmosphere to kilometres into the Pock of the Earth’s crust. Wherever iing things are found, that is the oosphere. An ecologist might study how the amount of light coming from the Sun affects the biosphere.

How could you design your landfill site to discourage bears from visiting?

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Interactions Within Ecos’tstems

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Matching Quiz for New Vocabulary Name:_________________________________

Date:

In front of each of the following definitions, place the letter for the term that best fits the description. Answers may be used once, more than once, or not at all. 1. 2. 3. 4. 5. 6. 7. 8. .

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The number of organisms of the same species living in a community. All the non-living physical factors which influence living things. The related ecosystems which share the same climate. A single living thing. The number of goldfish living in the pet store tank. The entire surface of a planet where life is found. A system of living things which interact with each other and with the physical world. All the effects caused by living things. All of the organisms that can interbreed under natural conditions to produce fertile offspring. An abandoned city lot which supports cats, mice, chickadees, ants, crabgrass and dandelions. All the living things found in the school grounds. A non-living factor, such as the amount of oxygen, which influences the living organisms. All the ecosystems of the Prairies which share similar temperature and precipitation ranges. Polar bears live on ice floes in Hudson Bay with bearded seals, ringed seals, herring, krill and algae. The number of humans in your classroom right now. Life does not exist on Venus, therefore it cannot be called this. All of the Earth’s biomes, when considered together. The number of dogs living in Sault Ste. Marie. A cat sleeping in a chair. All the plants, animals, fungi, and single-celled organisms found in a fish tank.

A) Biotic B) Abiotic C) Organism

D) Species E) Population F) Community

138 Interactions Wzthin Ecosyterns/B1ack1ine Masters

G) Ecosystem H) Biome I) Biosphere

© 2000 Nelson Thomson Learning

Grade 7 Science and Technology f Strand 1: Interactions in the Environment

Introduction to Food Chains and Food Webs (page 20) What is a food chain? IA food chain is a feeding relationship between organisms in an ecosystem. I I Energy is transferred from producers I tjo consumers and predators. J What is a food web? A food web is made up of several food chains in an ecosystem. What is an ecosystem? rAn ecosystem is a geographic area in which plants, animals, people, air; water; soil and rocks interact as a system.

The Sun Every food chain begins with the sun. Plants use sunshine to gather and store energy. Role: to provide plants with energy (sunlight> to live and breathe. Producers Producers are organisms (e.g., plants, algae) that use sunlight to make their own food. Role: to produce oxygen, to be food for organisms higher in the food chain. Consumers Consumers are organisms that feed on others below them in the food chain. Role: to eat organisms below them in the food chain, to reduce the number of rapidly multiplying organisms.

Teacher led discussion

Scavengers Scavengers eat dead or decaying plants or animals. Rats, racoons, vultures, crows, flies, beetles, millipedes and centipedes are a few examples of scavengers. Role: to remove unwanted refuse (dead or decaying plants and animals) from the surface of the Earth. Decomposers Decomposers like centipedes and microorganisms break down the remains of dead plants and animals. Role: to turn organic matter (dead plants & animals) into inorganic soil matter (soil minerals) which can be used by plants to grow.

Food Chain

Vertical Food Web

Tropical Grasslands Ecosystem: Small grass area in Kenya, Africa

Tropical Grasslands Ecosystem (savannah): Very large grass area in Kenya, Africa Tertiary Consumer: These animals eat animals

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Tertiary Consumer Lion eats Zebra to grow

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Primary Consumer Zebra eats grass to grow

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Every food chain begins with the sun

I Producers: Tall grasses, shrubs and tree leaves A Producer Tall grass A uses sunlight 1 to gather energy to grow

Mushrooms

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Gr 7 ONSCI*_Transpa,E6eity

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Grade 7 Science and Technology Strand 1: Interactions in the Environment Introduclion to Food Chains and Food Webs Teacher’s Answers (page 22)

Activity 5 C mplet. Cha

Instructions: Use the facts on page 20 to complete the following. 1) What is the role of producers in a food chain?

3) What is the role of decomposers in a food chain?

2) What is the role of consumers in a food chain?

To produce oxggen and to To consume and reduce provide organisms above the numbers of rapidhj multitluinL7 oruanicmc them with food. below them in food chain,

To return organic matter (dead plants and animals) to the coil ac inoraanic matter (coil minerals).

isstrctius: Construct a food chain in a smaN interior Ontario lake, Use the tollc wing organisms in your food chain: a Painted Turlie (tertiary consumer); b) Trout (secondary consumer); C) Frog (secondary consumer); d) Fry [newborn fish] (primary consumer); d) Aquatic plants (producer); Label each organism as a producer; primary consumer; secondary consumer.

Instructions: Construct a food web in the ocean near Australia. Use the following organisms in your food chain: Blue Marlin X a) People swimming (tertiary consumer); b) Great White Shark (tertiary consumer); c) Blue Marlin (secondary consumer); d) Tuna (secondary consumer); Tuna e) Big fish + small fish (secondary consumer); t) Fry [newborn fish] (primary consumer);

Small Lake Food Chain

Ocean Near Australia Food Web

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Label each organism as a producer; primary consumer; secondary consumer.

Tertiary Consumer Top predator Turtle is an omnivore Secondary

Consumer: Trout is a carnivore

Frog

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Fry (newborn fish)

Secondary Consumer; Frog is a carnivore

Primary Consumer: Fry feed on plants

Producer: Aquatic plants and algae use sunlight to gather energy

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Tertiary Consumers: top of food chain

These arrows show the feeding relationship and low of energy

Producers: bottom of food chain

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Grade 7 Science and Technology

Strand 1: Interactions in the Environment

Interconnected Vertical Food Webs (page 24)

Small animals

Every food chain begins with the sun

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Teacher led

What are tertiary consumers? (Animals that feed on other animals like secondary or primary consumers.

What are secondary consumers? Animals that feed on other animals like Lprimary consumers.

What are primary consumers? IAnimals that feed on producers like tplants and algae.

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What are scavengers? (Animals that feed on dead or decaying I plants or animals. Scavengers are LusuaIly in the middle of the food chaij

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What are decomposers? lAnimals + life forms that feed on th remains of dead plants and animals.

Soil bacteria

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Case Study

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Pesticides: Poisons in the Food Chain As much as 30% of the annual crop in Canada is lost to pests. The pests include weeds, rusts and moulds, birds, small mammals, and insects. For each of these pests, we have created a pesticide. Pesticides are chemicals designed to reduce the populations of unwanted organisms, both plant and animal.

Tires and Mosquitoes What do we do with worn-out tires? Burying tires in a landfill isn’t possible. After a few years they always push through to the surface. Just storing them separately has always been a problem, because old tires can burn. As tires burn they create a thick, choking smoke. There is another problem with tire dumps: tires make excellent troughs for collecting rainwater. The still water, warmed by the sun hitting black rubber, makes an agreeable ecosystem for hatching mosquitoes. (a) Why is it a problem to create a favourable ecosystem for mosquitoes?

LIi’[fl1I The malaria microbe is carried by one species of mosquito, The microbe cycles between animals such as humans and mosquitoes.

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A mosquito draws blood from an infected person and picks up the parasite.

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Malaria microbes infect red blood cells, which rupture and send spores into the bloodstream.

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the parasite is transferred in the next victim’s bloodstreai when the mosquito bites.

Mosquitoes and Disease Some mosquitoes carry microbes that cause disease. Malaria is one such disease, as shown in Figure 1. Thousands of people in tropical areas of the world die of this disease every year. (b) Used tires are often stored in one area and then moved to another area for disposal. What problem might this cause?

The parasite incubates in the liver and releases microbes into the bloodstream.

Using Pesticides Scientists developed a pesticide spray that could eliminate mosquitoes. When it was tried on an island, other effects were soon noted. Insects other than mosquitoes began to disappear, and then the number of lizards began to fall. (c) Why did scientists want to reduce the number of mosquitoes? 276

(d)What do you think caused some other insects to begin to disappear? (e) Provide at least two examples of insects that you would not want to destroy and explain why they are important. (f) Why might the lizards begin to disappear?

Unit 5

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The Problem Spreads

Understanding Concepts

Most people on the island were not too worried about the disappearanc e of a few insects and some lizards. Howeve r, they took notice once the local wildcats, wh ich had fed on dead lizards, began to get sick and die. Without the cats the rat popula tion soon increased. Fearing an outbreak of diseases linked with rats, the local people imported domestic cats.

1. Explain in your own words wha t pesticides are. 2. Why do pesticides create the greatest problems for carnivores?

Making Connections 3. In Atlantic Canada pesticides

called pyrethoids were used to control winter moths and leaf miners in apple orchards. Unfortunately, the chemicals kill ed more insects than intended, including predators of red mites and apple mites. After orchards were sprayed with pyrethoids, the mite population rose quickly, damaging the trees and reducin g the yield of apples. What recommendations would you make to anyone who planned to use pyrethoids?

(g) What problems could be caused by bringing in domestic cats?

nvasion of the Caterpillars Changes to the food web becam e even more obvious when caterpillar popula tions began to increase. Apparently, the pestici de affected wasps and other predators of the caterpillar, but it had little effect on the cat erpillars. Once the predators were gon e, the caterpillar population increased greatly. Eve ntually; caterpillars searching for foo d moved into fields and devastated food cro ps. (h) Use pictures of a beetle, cat, caterpillar, grasshopper, lizard, mosquito , rat. and wasp to draw a food web that shows the impact of spraying with the ins ecticide.

iological Amplification Pesticides tend to stay in the bod ies of animals that come in contact with the m. (If pests could easily get rid of the pes ticide, it would not he effective.) The result is that the concentration of harmful pesticides increa ses at each level in a food chain. Predators always have more toxic chemicals in their bodies than their prey, as shown in Fig ure 2.

If the body of the prey contain s harmful pesticides, the pesticides wil l he taken in by the predator. Predators eat many prey over their lifetimes. Each time pre y is eaten, the amount of pesticide in the predator increases. This process of increase at each level of a food chain is called biological am plification. (i) Predict how scavengers, such as beetles, might he affected b’ biolog ical amplification.

j2sign Challenge Make a list of the problems created by disposing of tires in a landfill site. What other kinds of garbage might cause similar problems? Think about some solutions. The concentration of a pesticide increases as it moves up the food chain. (in ths case the pes tcide is DDT.) The greater the number of links in the chain, the greater the amount of biologcal ampification. From wat er to osprey the concentration of DDT increases 10 million times.

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SUGGESTED ANSWERS TO QUESTIONS Case Study (a) Mosquitoes draw blood from people. Mosquitoes are pests for humans and their animals, and may transmit diseases. (b) Disease-causing mosquitoes can be transported from one ecosystem to another. The new ecosystem might not have natural predators that regulate the numbers of the disease causing mosquitoes. (c) By reducing the number of mosquitoes, scientists hoped to reduce disease. (d) Other insects were also affected by the pesticide. (e) Many different examples could be provided. They include: bees because they pollinate flowers and make honey, dragonflies because they are a natural control on mosquitoes, and scavenger beetles because they act as decomposers within an ecosystem. (f) The lizards ate the insects and the toxic pesticides were absorbed into their organs. (g) Many different hypotheses may be accepted; a few samples are provided. The domestic cats might introduce new diseases. The new cats might multiply rapidly and alter the food web. The new cats might find another food source and leave the rats alone.

(h) After completing the food web, remove the mosquito to view the effect of the pesticide. (i) Beetles would take in high concentrations of pesticides from higher-order consumers.

Understanding Concepts 1. Pesticides are chemicals designed to reduce the populations of unwanted organisms, both plant and animal. 2. Pesticides tend to stay in the bodies of animals that come in contact with them. The result is that the concentration of harmful pesticides increases at each level in a food chain. Predators always have more toxic chemicals in their bodies than their prey.

Making Connections 3. Check to see what effect the pyrethoid had on higher-level consumers. If the insecticide is more harmful for predators than pests, expect the population of pests to increase over time.