Unit 4 Preparation: Introduction to Sustainability
Population
• A population is a group of organisms of the same species living in the same area at the same time.
Community
• A community is composed of all the populations that live and interact with each other in a particular
area.
Ecosystem
• A community of organisms interacting with each other and with non-living factors in their environment
Biotic Factor
Biotic factors are living things within an ecosystem such as plants, animals and micro-organisms.
Abiotic Factors
Abiotic factors are non-living things in an ecosystem such as water, oxygen, light, temperature,
nutrients, soil and salinity.
Photosynthesis
• Photosynthesis is a process that occurs in the cells of plants, algae, and some bacteria that convert
light energy from the Sun into chemical energy.
Cellular Respiration
• Cellular respiration is a process that occurs in the cells of organisms that converts the energy stored in
chemical compounds into usable energy
Producer
• A producer is any organism that obtains the energy it needs by producing its own food.
• Also known as autotrophs (self feeders)
Consumer
• A consumer is an organism that obtains the energy it needs by eating producers or other consumers.
• Also known as heterotrophs (other feeders).
Decomposer
• Decomposers are organisms that obtains energy consuming dead plant and animal matter.
Trophic pyramid
• A trophic pyramid is a model that shows the transfer of energy from one level of organism to the next
within a food chain.
Nutrient
• A nutrient is any substance that an organism needs to sustain its life.
Nutrient Cycle
• The pattern of continual use and reuse of nutrients needed by living things.
Succession
• Succession is a series of natural changes that occur over time following a disturbance such as a forest
fire, flood, windstorm or the construction of a beaver dam.
Primary Succession
• Primary succession occurs in areas that are lacking soil.
• This photograph shows primary succession occurring after lava flow.
Secondary Succession
• Secondary succession occurs in areas that were preciously inhabited.
Climax Community
• A stable, mature community that results when there is little change in the species inhabiting the
community.
Question 1
An ecosystem is a community of organisms interacting with each other and with non-living factors in their
environment.
Question 2
Possible responses:
Large ecosystems include forests, croplands, rivers, lakes and oceans.
Small ecosystems include a rotting log, small pond or a puddle of water.
Question 3
Answer E
Abiotic factors: temperature, light, oxygen, water, soil, nutrients, moisture, space and salinity.
Question 4
Biotic factors include bird, mammals, trees, berries, flowers, nuts, seeds, grasses.
Abiotic factors include rocks, air, and water.
Question 5
5a. A mushroom is a decomposer because it obtains energy by consuming dead plant and animal
matter.
5b. A tree is a producer because it uses energy from the sun to create food.
5c. A chipmunk is a consumer because it gets energy by eating seeds produced by plants.
Question 6
Your food chain should show at least three organisms including a consumer that eats a consumer that
eats a producer.
Grass – deer – wolf
River grass – fish – bear
Question 7
Answer E
None of the organisms listed were consumers.
Question 8
Answer D
Grass was the only producer listed.
Question 9
The floating algae is a producer.
The mosquito larva, minnows, and perch are all consumers.
Question 10
Possible responses:
Green plants – mouse – weasel – great horned owl
Green plants – insects – shrew – great horned owl
Green plants – grouse – great horned owl
Green plants – snowshoe hare – weasel – great horned owl
Question 11
Your energy pyramid should include four levels with a producer at the base, and appropriate consumers
at each level above the producers.
The pyramid should also include information about energy available at each level.
Question 12
Your answer should include the benefits that trees provide to different parts of the ecosystem:
They provide shade and shelter (habitats) for organisms.
They produce food for other organisms.
They provide oxygen required by other organisms through the process of photosynthesis.
Their leaves capture sunlight and when they fall off they provide food for decomposers.
Question 13
Your flow chart should show cause and effect.
Example: Hunters kill all the wolves in the area.
The population numbers of prey the wolf eats (i.e., rabbits) increases significantly. The population
numbers of the producers that rabbits eat (grasses and berries) decreases significantly.
Question 15
A nutrient is any substance that an organism needs to sustain its life and nutrient cycles are patterns of
continual use and reuse of the same nutrients required by living things.
Question 16
A decomposer is an organism that obtains energy by consuming dead plant and animal matter (biotic).
Nutrients from the decomposed animals and plants (abiotic) are released into the soil during
decomposition.
The nutrients are then taken up by plants (producers) as they grow.
Question 17
Photosynthesis requires sunlight, carbon dioxide and water.
Question 18
The diagram shows a cycle, which demonstrates that all living things are connected and that energy and
matter are constantly being transferred through food webs, which include decomposers, and nutrient
cycles.
Question 19
During cellular respiration organisms release water and carbon dioxide.
Question 20
Your drawing should show that the products of photosynthesis are the reactants in cellular respiration
and vice versa.
Question 22
Succession is a series of natural changes in an ecosystem that occurs over time following a disturbance
such as a forest fire, flood, windstorm or the construction of a beaver dam.
Question 23
I agree with this statement because primary succession is a gradual change in the community structure,
beginning with a pioneer community and leading toward a climax community.
Question 24
A beaver meadow may be ideal for organisms such as deer, fox, rabbits, mice, birds, insects, grasses
and wildflowers.