Dolan’s Ecology Review – Chapters 2-5
1. Describe each of the 6 levels of ecological organization. Be Specific
1. Individual- an organism
2. Population- – a group of individuals of the same species living in the same geographic area
3. Community – different populations that live together in the same geographic area
4. Ecosystem– a collection of communities in an area plus the abiotic factors
5. Biome-a group of ecosystems that have the same climate and communities present
6. Biosphere-the portion of the Earth in which all life exists
2. Look at figure 14, page 43 of your Zebra textbook. Which organism would be the producer? Which is the primary consumer? Secondary? Tertiary? Be able to pick out examples of each.
Primary (autotroph- makes its own food- primary consumer (eats producer)- secondary (eats primary) tertiary (eats secondary)
3. What provides almost all of the original energy in ecosystems?
Plants- producers/autotrophs
4. Define the following terms:
· Autotroph- producer w/ sunlight (plants)
· Heterotroph- consumer
· Chemotroph-producer w/ chemicals (deep oceans)
· Producer- makes own food
· Consumer- eats producers or other consumers
· Decomposer-breaks down rotting and dead organisms
· Herbivore-plant eater
· Carnivore-meat-eater
· Omnivore-eats both
5. What does a biomass pyramid show?
shows how much biomass there is at each level. Biomass is the amount of living tissue within a given trophic level. Biomass is usually expressed in grams (g) or kilograms (kg) per meter2. The greatest amount of biomass is at the bottom of the pyramid.
6. A numbers pyramid?
shows how many individuals are at each trophic level.
For example: blades of grass to the # of rabbits to the # of owls (per acre)
The greatest number of individuals is at the bottom of the pyramid
7. An energy pyramid?
shows how much energy is transferred to each trophic level. Only 10% of the energy moves on to the next level! The rest of the energy is eliminated as heat.
8. Explain the key parts of each of the following “biogeochemical”cycles
a. Water cycle
All living things require water to survive
Water moves through the biosphere using the water cycle
Parts of the Water Cycle
Liquid to Gas (evaporation, etc.)
Gas to Liquid (condensation)
Solid to Liquid (melting)
Liquid to Solid (freezing)
Movement of water on land (runoff, infiltration, percolation)
b. Nitrogen cycle
All living organisms require nitrogen to make amino acids (amino acids are used to make proteins)N2 (nitrogen gas) makes of 78% of atmospheric gases Oxygen makes up only about 20% Nitrogen- fixing bacteria are essential to the nitrogen cycle Helps to transform nitrogen into a useable form Found in plant roots and in the soil
c. Carbon cycle
Carbon is the key ingredient for all living tissues
There are 4 processes that move carbon:
1. Biological processes
For example: photosynthesis, cellular respiration, decomposition
2. Geological processes
For example: erosion, volcanic activity
3. Mixed processes
For example: burial and decomposition of organisms
4. Human activities
For example: mining, deforestation, burning fossil fuels
9. How is carbon stored in the biosphere?
Carbon dioxide CO2
10. Define climate.
the specific weather pattern of an area over a period of time
11. What is a niche?
the role an organism plays in an ecosystem
12. Describe: symbiosis, mutualism, parasitism, and commensalism.
Symbiosis: any relationship in which two species live closely together
3 types of symbiosis:
Mutualism – both organisms benefit ( Flowers and insects)
Commensalism – one organism benefits, the other is neither harmed nor helped
For example: Birds on rhino/antelope’s backs; sharks and ramora fish; whales and barnacles
Parasitism – one organism hurts, the other benefits ( Tick and humans; fleas and dogs)
13. What are some ways that competition in a habitat can be reduced?
Fewer predators due to biotic factors (mating decreases, diseases)
14. Define the following:
a. Population growth-the specific weather pattern of an area over a period of time
b. Ecological succession-the specific weather pattern of an area over a period of time
c. Climax community- stable, mature ecological community with little change in organisms
d. Population density-the specific weather pattern of an area over a period of time
15. What can you tell from the range of a population?
The areas inhabited by a population
16. What is exponential growth?
populations with unlimited resources
J curve
Logistic growth? exponential growth until a resource becomes limited
S curve
17. What is the carrying capacity of an environment?
amount of individuals in a population that an area can support
18. What is a limiting factor?
biotic (living) or abiotic (nonliving) factor that can limit growth
19. What is the difference between a
density independent limiting factor
Affect of factor does not depend on population density
Climate changes, natural disasters, and human disturbances
density dependent limiting factor
factor increases with increasing population density (competition, parasitism, predation, disease)
20. What is the term for the study of human populations?
Demography
21. Define sustainable development.
the quality of not being harmful to the environment or depleting natural resources, and supporting long-term ecological balance
22. What is biodiversity?
variety of life in an area.
Important because: Provides varied resources, Food, Products, Medicines, Creates ecosystem stability
23. Name at least 3 threats to biodiversity.
Habitat Loss Deforestation Overexploitation (overuse) Habitat Fragmentation Pollution
Biomagnification, acid precipitation Introduction of Invasive species
24. Describe the process of biological magnification. Do chemical levels increase or decrease as they move up the trophic levels?
Chemical pollutant becomes more concentrated as it moves up the trophic levels within a food chain or web Very dangerous for top level predators
25. What forms when sulfur and nitrogen compounds in smog combine with water?
Acid precipitation
26. What is the major cause of ozone depletion?
CFC’s (chlorofluorocarbons) -- an organic compound that is used in refrigerants, spray cans, Styrofoam, fire extinguishers travel into the high atmosphere, and react with sunlight to destroy the ozone