2. Ecology is the study of relationships between organisms
and between organisms and their environment.
Organisms are described at various levels of organization.
Species – a group of organisms that can interbreed and
produce fertile offspring.
5.1.1
3. Population - a group of organisms of the same species
who live in the same area at the same time.
Community – a group of populations living in and
interacting with each other in an area.
5.1.1
4. Ecosystems - a community and its abiotic factors
Habitat – the environment in which a species normally
lives.
5.1.1
5. In an ecosystem, biotic factors are living and abiotic
factors are non-living (temperature, precipitation, etc.)
5.1.1
7. The sun in the ultimate source of energy in the biosphere.
Autotrophs (aka producers) are organisms that are able to
use light energy to synthesize organic molecules from
simple inorganic substances. Use photosynthesis.
Heterotrophs (aka consumers) are organisms that obtain
energy from other organisms via cell respiration.
5.1.2
8. Different types of heterotrophs
include:
• Consumers – organisms that ingest
other organic matter this is living
or recently killed
• Detritivore – organisms that ingest
non-living organic matter
• Saprotroph – organisms that live
on or in non-living organic matter,
secreting digestive enzymes into
and absorbing the products of
digestion.
5.1.3
10. A food chain is a linear model
that shows how energy and
matter move in an ecosystem.
Arrows indicate the
movement of energy and
matter from one organism to
another.
Sun Plant Frog Fish Walrus Polar Bear
5.1.4
17. Solar light/energy is the initial energy source of any food
chain or web. It is converted to chemical energy by
producers via autotrophy and then moved by heterotrophs.
First Trophic
Level
Second Trophic
Level
Producers
(plants)
Primary consumers
(herbivores)
Heat
Third Trophic
Level
Secondary
consumers
(carnivores)
Heat
Fourth Trophic
Level
Tertiary consumers
(top carnivores)
Heat
Solar
energy
Heat Heat
Heat
Heat
Heat
5.1.9
18. Energy converted by autotrophs is consumed by
heterotrophs and moved through the trophic levels.
However, this movement is not 100% efficient.
Some material is not consumed and energy at each
level is lost as heat and used for other life processes.
5.1.10-11
20. Energy pyramids show the flow of energy from one
trophic level to the next in a community. Energy is
measured in kJ m-2 yr-1.
5.1.12
21. About 90% of energy is a trophic level is used, so only
10% is passed to the next level, which results in an
energy pyramid’s narrowing shape.
5.1.12
22. Although energy can leave an ecosystem, nutrients must
be recycled. They can be introduced via rock
weathering and taken up by producers. Decomposers
recycle nutrients from dead organic matter.
5.1.13
23. An ecosystem survives through a combination of energy
flow and matter recycling. Saprotrophs and fungi play a
large role in nutrient recycling.
Saprotrophs
Fungi
5.1.14
25. 1. Distinguish between habitat and ecosystem.
2. Look at these food chains again. Determine the trophic levels for
each organisms listed.
1.
2.
3.
Grass grasshopper toad hognose snake hawk
Algae mayfly larva trout kingfisher
Diatoms copepods herring seal shark
3. From the following information, construct a food web:
–
–
–
–
–
–
–
Grass is eaten by rabbits, grasshoppers and mice
Rabbits are eaten by hawks
Grasshoppers are eaten by toads and mice and garter snakes
Mice are eaten by hawks
Toads are eaten by hognose snakes
Hognose snakes are eaten by hawks
Garter snakes are eaten by hawks
4. From the food web in 3, determine the trophic level of the toad.
5. Answer the first three pages from the review packet.
5.1
Notes de l'éditeur
5.1.1 – Define species, habitat, population , community, ecosystem and ecology
5.1.1 – Define species, habitat, population , community, ecosystem and ecology
5.1.1 – Define species, habitat, population , community, ecosystem and ecology
5.1.1 – Define species, habitat, population , community, ecosystem and ecology
5.1.1 – Define species, habitat, population , community, ecosystem and ecology
5.1.2 – Distinguish between autotroph and heterotroph
5.1.3 – Distinguish between consumers, detritivores and saprotrophs.
5.1.3 – Distinguish between consumers, detritivores and saprotrophs.
5.1.4 – Describe what is meant by a food chain, giving three examples each with at least three linkages (four organisms)Only real examples should be used from natural ecosystems. Each food chain should include a producer and consumers, but not decomposers. Named organisms at either species or genus level should be used. Common species name can be used instead of binomial names. General names such as “trees” or “fish” should not be used.
5.1.4 – Describe what is meant by a food chain, giving three examples each with at least three linkages (four organisms)Only real examples should be used from natural ecosystems. Each food chain should include a producer and consumers, but not decomposers. Named organisms at either species or genus level should be used. Common species name can be used instead of binomial names. General names such as “trees” or “fish” should not be used.
5.1.5 – Describe what is meant by a food web
5.1.6 – Define trophic level.
5.1.7 – Deduce the trophic level of organisms in a food chain and a food webStudents should be able to place an organism at the level of produce, primary consumer, secondary consumer, and so on, as the terms herbivore and carnivore are not always applicable.
5.1.8 – Construct a food web containing up to 10 organisms, using appropriate information.
5.1.8 – Construct a food web containing up to 10 organisms, using appropriate information.
5.1.9 – State that light is the initial energy source for almost all communities.No reference to communities where food chains start with chemical energy is required.
5.1.10 – Explain the energy flow in a food chain. Energy losses between trophic levels include material not consumed or material not assimilated and heat loss through cell respiration.5.1.11 – State that energy transformations are never 100% efficient. Reference to the second law of thermodynamics is not expected.
5.1.10 – Explain the energy flow in a food chain. Energy losses between trophic levels include material not consumed or material not assimilated and heat loss through cell respiration.5.1.11 – State that energy transformations are never 100% efficient. Reference to the second law of thermodynamics is not expected.
5.1.12 – Explain reasons for the shape of pyramids of energy.A pyramid of energy shows the flow of energy from one trophic level to the next in a community. The units of pyramids of energy are, therefore, energy per unit area per time, for example, kJ m-2 yr -1
5.1.12 – Explain reasons for the shape of pyramids of energy.A pyramid of energy shows the flow of energy from one trophic level to the next in a community. The units of pyramids of energy are, therefore, energy per unit area per time, for example, kJ m-2 yr -1
5.1.13 – Explain that energy enters and leaves ecosystems, but nutrients must be recycled.
5.1.14 – State that saprotrophic bacteria and fungi (decomposers) recycle nutrients.
