Unit B: Interactions in the Environment (Pg. 88 – 173)
Chapter 6: Organisms Depend on a Healthy Environment (pg. 146 – 167)
6.1: The Dynamics of Nature: Succession (Pg. 148- 150)
Check Your Learning: Read Pages 148-150. Answer the following questions:
1.
Define the followings:
a) Succession: A series of gradual changes that result in the replacement of one community of plants and animals by
another.
b) Primary succession: Succession that develops a community of plants and animals in an area where no living things
existed before.
c) Secondary succession: Succession that develops a community in an area after it has been disturbed.
2.
What is the difference between primary and secondary succession?
Primary succession occurs in an area where no living things exist. Secondary succession occurs in an area that has
previously sustained life, but has been disturbed by a natural or human-made event.
3.
Explain how humans interfere with succession. How does this negatively affect ecosystems?
Humans may clear-cut a forest and eliminate an entire ecosystem. Instead of allowing the area to recover through
succession, humans may plant one type of tree, such as pine tree. As a result, there are fewer animals that can live in
the area because there is only one type of plant to eat. In addition, this increases the likelihood of the area being
wiped out by a disease or pest invasion.
6.2: Human Impact on Ecosystems (Pg. 151- 154)
Check Your Learning: Read Pages 151-154. Answer the following questions:
1.
What is habitat loss?
Habitat loss occurs when areas of land are cleared for human use, destroying the places where wild organisms live.
2.
a) What is biodiversity? Biodiversity is a measure of the number of different species in an ecosystem.
b) How are habitat loss and biodiversity connected? When habitat loss occurs, the biodiversity of an area generally declines.
3.
a) Define invasive species and native species.
An invasive species is a species that did not originate in an area, but has been introduced (generally due to human
actions) and now out-competes the native species. Native species are those that occur naturally in an area.
b) How do invasive species cause harm to the environment?
Invasive species generally do not have natural predators in their environment. This means that they can grow and
reproduce quickly and successfully, out-competing the native species for resources. As a result, the native species are
often pushed out and the biodiversity of the area decreases.
c) Name two invasive species found in Ontario and explain how they harm the environment.
1. Zebra mussels: They clog intake pipes of treatment plants. They also affect food chains by competing with native
species for food.
2. Garlic mustard: It out-competes native plants for nutrients and space. The animals that feed on the native plant
species lose a food source.
4.
Define the followings:
a) Endangered species: Species that are at risk of becoming extinct due to either reduction in numbers or an
environmental threat.
b) Extinction: The complete disappearance of a species from anywhere on Earth.
6.4 Protecting the Environment (Pg. 156- 159)
Check Your Learning: Read Pages 156-159. Answer the following questions:

A hectare (ha) is a unit of area equal to 10,000 m2
1.
a) What is an ecological footprint?
An ecology footprint is an estimate of the amount of land and water needed to produce all of the things a person
consumes and to absorb all of the waste the person produces.
b) How many hectares of land does a North American need to sustain him or herself?
The average North American’s ecological footprint is about 12.4 hectares.
c) How many hectares are available for each human of Earth?
There are about 2 hectares available for every person on Earth.
2.
What is meant by conserving ecosystems?
Conserving ecosystems means using the resources of the ecosystems wisely.
3.
How does organic farming help to conserve ecosystems?
Organic farming methods use compost and biological pest control techniques to keep soil productive without
destroying the soil’s natural balance.
4.
What problem is created by improperly built landfill sites?
Water from rain and snow soaks through the waste and carries contaminants into the soil and groundwater.
5.
a)
b)
Name two ways in which people can help restore ecosystems.
By planting trees
By increasing the variety of plant species growing in lawns
6.5 Traditional Knowledge and Stewardship of Earth (Pg. 160- 161)
Overall Expectations:
3.9
1
Specific
Expectations:
Check Your Learning: Read Pages 160-161. Answer the following questions:
1.
a) What is Traditional Knowledge?
Traditional Knowledge is knowledge, experience, and practice gained by Aboriginal people over many generations of
living and working with the environment.
b) How is Traditional Knowledge passed on from generation to generation?
It is passed from generation to generation through actions, stories, poems, paintings, rituals, and other traditions.
2. In what ways can Traditional Knowledge help Ontario strive toward sustainability?
Aboriginal people can teach us how to use natural resources in a sustainable way by teaching us their skills and
techniques for managing the land and its resources.
Chapter 6: Chapter Review (pg. 166 – 167)
1.
What is the difference between an endangered species and an extinct species?
An endangered species is one that is still found on Earth, but is in danger of becoming extinct. An extinct species is
one that no longer exists on Earth.
2.
What is the “ecological footprint”?
An ecological footprint is an estimate of the amount of land and water needed to regenerate the resources a person
uses and to absorb the wastes the person produces.
3.
Preserving, conserving, and restoring are three methods of helping to prevent habitat loss. Briefly explain each one
and give an example of each.
Meaning
Example
Preserving:
It means leaving an area undisturbed.
There are areas of untouched forest in northern
Ontario that should be protected from future
logging.
Conserving: It means using ecosystems wisely.
Using organic farming methods.
Restoring:
It means taking steps repair damage done Planting trees to repair soil erosion.
by human activity.
4.
a) What are the environmental “three Rs”?
The environmental “three Rs” are: Reduce, Reuse, and Recycle.
b) Explain how each one helps the environment.
Reducing: Reducing the amount of products we consume helps the environment because making food, clothing and
other products uses natural resources. If we consume fewer products, fewer natural resources are consumed, which
helps conserve Earth’s resources.
Reusing: Reusing products helps the environment because it reduces the amount of waste we produce. Wastes can
cause pollution and other environmental problems.
Recycling: Recycling products protects the environment because it reduces both the amount of energy and other
resources required to make products and reduces the amount of waste we produce.
5.
Explain in your own words the meaning of “sustainability.”
The sustainability of a process describes whether the process can continue to occur in its current state without
depleting resources.
6.
Define “succession” in your own words.
Succession is the gradual change in the communities that exist in an ecosystem.
9.
Why is biodiversity so important to healthy ecosystems?
The more organisms that live in an ecosystem, the higher the ecosystem’s biodiversity. In general, ecosystems with
high biodiversity (a large number of different kinds of organisms) are better able to survive stresses, such as floods
and disease , without collapsing.
12.
Why has the expansion of urban centres become a concern?
Expanding urban centres by building homes, stores, and infrastructure such as roads and sewer systems results in
the loss of habitats for local wildlife. This causes a reduction in biodiversity, as animals and plants die or leave the
area. Fewer trees can also result in the erosion of soil, further depleting nutrients and biodiversity in the area. Larger
urban centres also produce more pollution in a smaller, more concentrated area, which increases ecosystem damage.
Automobiles and other vehicles create smog and other air pollution, and trash can run off into water bodies. More
people require more food and water, which puts a greater stress on local water systems and farmers, who may decide
to use toxic pesticides or fertilizers in order to grow more crops.
13.
List some of the ways that we can protect our natural habitats from invasive species.
Learn to identify and report invasive species, prevent invasive species from entering ecosystems, and find ways to
eliminate invasive species in ecosystems can all help protect natural habitats from invasive species.
Unit B - Unit Review (pg. 170 – 173)
1.
The essential abiotic elements of an ecosystem are: sunlight, air, water, nutrients, and a livable temperature range.
2.
A habitat is the environment where an organism lives. An ecosystem is the network of interactions linking the living
and non-living parts of an environment.
4.
Temperature is one of the main factors that determine which organisms can live in a particular environment. If it is
very hot or very cold, only a few highly specialized organisms can survive. It the temperature range is more moderate, a
wide variety of organisms can flourish.
6. a) An apple tree is a producer. The humans who eat the tree’s apples are consumers.
b)
Producers
Consumers
1 They can make their own food using abiotic elements in their They get their food by eating other organisms
2 environment
They take in oxygen and release carbon dioxide
3 They take in carbon dioxide from the air and release oxygen
They are not the first links in a food chain
They are the first ling in a food chain
7.
phytoplankton
Producer
shrimp
Primary Consumer
fish
Secondary Consumer
human
Tertiary Consumer
8. The amount of sunlight that an area receives limits the number of plants that can grow. Similarly, the number of plants in
an area limits the number of consumers, since there is a limited supply of food for the herbivores, which in turn limits the
number of carnivores that prey on the herbivores.
9. Decomposers such as bacteria break down organic matter from deal plants and animals releasing nutrients such as
minerals, nitrates, and phosphates into the soil, making them available for living plants to take in.
10. The water and carbon cycles interact at photosynthesis as plants use water and carbon dioxide to produce their food.

In the carbon cycle, plants take in carbon dioxide from the atmosphere/ they release carbon dioxide back into the
atmosphere directly when they decompose and indirectly when they are eaten by animals; animals release carbon dioxide
into the atmosphere when they decompose and also when they exhale. Some decomposing plants and animals are buried
underground over long periods of time become fossil fuels that humans burn to produce energy; burning fossil fuels release
carbon dioxide back into the atmosphere.

In the water cycle, the Sun causes water to evaporate from water bodies. The resulting water vapour travels into the
atmosphere, where it cools and condenses into clouds and eventually falls back to Earth as precipitation. Some of the
precipitation travels by surface runoff from the land to water bodies, where it evaporated once more. Some water seeps
underground, where it is stored as groundwater until it gradually seeps back into the ocean.
12. Plants are responsible for converting the energy from sunlight into the energy stored in sugars. The plants are eaten by
primary consumers. The primary consumers are then eaten by secondary and tertiary consumers, and in this way energy is
passed from the Sun throughout the ecosystem. Plants also remove carbon dioxide from the air and release oxygen, which
animals need to survive.
14. In a closed system, the amount of matter remains the same over time. On Earth, for example, the numbers of atoms of
carbon, oxygen, hydrogen, and the other elements has neither increased nor decreased (with the exception of meteorites
bringing some new matter to Earth from space). Matter is simply recycled.
17. Without detrivores such as earthworms, dead plants and other matter would not be broken down into smaller pieces. The
dead matter would piled up, taking up space needed by living organisms, and the nutrients in the dead matter not be released
back into the soil. Without fresh supplies of nutrients, living plants would soon die, affecting most food chains.
22. Because Traditional Knowledge includes the practices of people who have lived sustainable lifestyles for many
generations, it can teach us strategies for conserving resources and preserving the environment. Technology can then be
used to transmit this knowledge to large numbers of people. Traditional Knowledge can also be implemented into
technology, producing machines and practices that are less disruptive to the ecosystems in which they are used.
Student Success Workbook – Chapter 6
6.1 The Dynamics of Nature: Succession: Pg.111
1. Explain Succession in your own words. Succession is when the types of organisms in an ecosystem change over time.
2. What is the difference between primary and secondary succession?
Primary succession happens in areas where no organisms lived before. Secondary succession happens after
something (humans or nature) disturbs an existing community…
3. How can humans interfere with succession?
Humans often replace complex ecosystems with simple ecosystems. These ecosystems support fewer organisms…
6.2 Human Impact on Ecosystems: Pg.117
1.
Explain biodiversity in your own words.
Biodiversity is the variety of organisms in Earth’s ecosystem.
2.
What are some things that cause habitat loss? Humans clean land to build roads and stores. Humans farm and
mine land.
3.
How do invasive species harm ecosystems?
Invasive species have few natural predators, so they can push out native species from an ecosystem.
4.
Key Question: How are habitat loss and biodiversity connected?
When humans cause habitat loss, organisms in the area die or move away. There are fewer species in the ecosystem,
so the biodiversity of the ecosystem decreases.
6.4 Identify Examples of Stewardship: Pg. 123 & 124
Page 123:
1.
What is an ecological footprint?
An ecological footprint measures the amount of Earth’s resources a person uses.
2.
a) What does it mean to be a “steward?”
A steward carefully manages a resource.
b) What are some things that stewards of the environment do? They learn about environmental issues and make
choices that help the environment. They also tell others how to help the environment.
3.
Why do people preserve some areas of land?
People preserve land so that humans cannot harm it. Preserving land protects biodiversity.
4.
Key Question: How can humans help conserve resources? Give two examples.
Humans can reduce, reuse, and recycle. (Ex. we can reuse items, such as boxes. We can also put food waste in a
composer.)
Page 124: Read the sentences below. Decide whether each situation describes: preservation, conservation, or restoration.
a)
A garden club plants trees for birds that lost their habitat.
Restoration
b)
A provincial law says that humans cannot build houses next to a wetland environment.
Preservation
c)
Students put food waste from lunch into a compost bin.
Conservation
d)
A family adds many native plants species to their garden to increase its biodiversity.
Restoration
e)
A farmer uses compost instead of chemical fertilizers.
Conservation
6.5 Traditional Knowledge and Stewardship of Earth: Pg.127
What is Traditional Knowledge?
Traditional Knowledge is the ideas, customs, and experiences of Aboriginal peoples.
2.
How do Aboriginal peoples pass Traditional Knowledge on to new generations? Through songs, stories, poems,
and laws.
1.
4. Key Question: How can people use Traditional Knowledge? People can learn how to take care of the environment and
use resources wisely.
Unit B: Interactions Within Ecosystems
Grade 7 Quiz – Chapter 4: Healthy Ecosystems
Name (s): ________________________________________
Parents Signature: _____________________________________
Date: ___________________
Mark: _________ =
%
50
A) True/False: (7 Marks) Indicate whether each statement is true or false. If the statement is false, change the statement to make it true.
1. __F__ A community is all of the organisms of a particular species that live in an area.
A community is all of the population that live in an area (OR is all of the organisms of a particular species that live in
an area)
2. __F__ Mutualism is a relationship between two species in which one species benefits and the other is harmed.
Mutual ism is a relationship between two species in which both species benefit (OR predator-prey is..)
3. __T_ Abiotic elements of an ecosystem include air, water, and sunlight.
___________________________________________________________________________________________
4. F A Population is made of members of different species.
A population is made of members of same species (OR a community is made of members of different species)
5. F Organisms are biotic because they are non-living things.
Organisms are biotic because they are living things (OR organisms are abiotic because the are non-living..)
6. F One advantage of fertilizers is that they can protect crops from insects.
One advantage of fertilizers is that they can protect crops from insects (OR one adv. Of pesticides is to…)
7. T One disadvantage of pesticides is that they can pollute the soil and water.
___________________________________________________________________________________________
B. Fill in the blanks: (10 Marks)
Using the spaces provided, select the word that best fits the description. Answers may be used only once.
abiotic
species
population
biome
biosphere
community
organism
ecosystem
biotic
habitat
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Biotic all the effects caused by living things.
Abiotic all the non-living physical factors which influence living things.
Organism
a single living thing
Species all of the organisms that can interbreed under natural conditions to produce fertile offspring.
Population
the number of organisms of the same species living in a community.
Habitat the place in an environment where an organism lives.
Community
all the living things found in the school grounds.
Ecosystem
a system of living things which interact with each other and with the physical world.
Biome
the related ecosystems which share the same climate.
Biosphere
all of the Earth’s biomes, when considered together.
C) Completion: Answer the following questions by writing in the space provided. (10 Marks)
1. Every ecosystem is made up of biotic, or living elements, and abiotic, or non-living elements.
2. An organism’s habitat is the environment in which the organism lives.
3. The general term given to all of the populations of organisms within an ecosystem is called a community.
4. Organisms use food as a source of nutrients.
5. Many snakes and lizards use sunlight to warm their bodies.
6. Animals use water to digest food and form body fluids.
7. Plants use carbon dioxide from the air to make food.
8. Brook trout have an ideal temperature between 4 oC and 20 oC.
9. Mutualism is an interaction between individuals of different species that benefits both individuals.
D. Multiple Choices: Select the letter of the item that correctly represents each statement: (10 Marks)
1.
_ c__
What are the basic needs of living things?
a) Food, clothing, water, oxygen
c) Air, water, food, sunlight
2.
_ d_
a)
b)
c)
d)
3.
b) Water, shelter, forests, temperature
d) Shelter, food, oxygen, minerals
Ecology is the study of:
The relationship between living things and their environment
The interactions between biotic and abiotic parts of the environment
The interactions between organisms and the places where they live
All of the above
_b_
The biotic components of a landfill ecosystem include:
a) Temperature, beetles, mould
c) Bacteria, oxygen, mice
b) earthworms, bacteria, millipedes
d) Centipedes, scavenger beetles, garbage
4. __c__
A scientist is studying abiotic element in an ecosystem. Which of the following abiotic elements was most
likely added to the ecosystem by humans?
a)
c)
5.
__b__
a)
b)
c)
d)
6.
Oxygen in the air
Toxic metals in the soil
b) water in a stream
d) rocks under the ground
Which of these situations is the best example of mutualism?
two pigeons fighting over a piece of garbage
a guard dog protecting the people who feed it
bacteria making a person sick when they enter a cut and multiply
an earthworm breaking soil apart as it eats the remains of plants and animals.
__d__
A group of similar organisms that can mate and reproduce more of the same type of organism.
a) population
b) organism
c) community
d) species
7.
__a__
A group of organisms of the same species in a given area.
a) population
b) organism
c) community
d) species
8.
__c__
A group of populations of different species in a given area
a) population
b) organism
c) community
d) species
9.
__b__
Occurs when more than one organism tries to obtain the same basic resources in the same habitat.
a) mutualism
b) competition
c) predation
d) ecosystem
10. __a__
An interaction between individuals of different species that benefits both individuals.
a) mutualism
b) competition
c) predation
d) ecosystem
E) Q & A: Answer the following questions: (13 Marks)
1. What is the difference between a predator and a prey?
Predator:
Prey:
An animal that hunts other living things for food.
An animal that is hunted by a predator.
2. Explain why sunlight is a basic need for both plants and animals. (Give two reasons)
a) Plants need light energy to make their own food. The sun’s energy is passed along to animals when they eat plants or
other animals that have eaten plants.
b) Animals and plants also need the sun to keep Earth at an ideal temperature.
3.
Explain how competition affects the number of organisms that can live in a habitat.
The number of organisms that can live in a habitat depends on the amount of resources in the area. Organisms have to
compete for the same resources. When the resources are limited, some organisms die or move to another area.
4.
The desert is an environment with very little water. How does this affect the types of organisms that can live there?
Only organisms that need a small supply of water could live in a desert. Organisms that need a large supply of water could
not survive.
5.
How do animals get energy from sunlight?
Some animals eats plants, which have already used sunlight to make food.
6. Name two ways that plants affect human survival.
Plants help humans survive by:
a) Producing oxygen which we need to breathe,
b) Providing us with food
7) What are the five basic needs of all living things?
Sunlight, air, water, food, and ideal temperature.
8) How do organisms that live in water get the gases they need?
Water has dissolved gases (O2 and CO2). Most plants and animals that live in water absorb these gases from the water.