Chapter 4 & 5 - Ecology Unit Review Sheet
Name ___________________________________
Put your answers on a separate sheet – do not try to squeeze your answers on this paper!
Review all of your notes and vocabulary words.
1. Define ecology.
Study of the relationship between living and nonliving things
2. Define abiotic and give an example of an abiotic factor.
Nonliving
Air currents, temperature, moisture, light, soil
3. Define biotic and give an example of a biotic factor.
Living organisms
Other organisms in the environment, plants, etc.
4. List the 6 levels of organization of ecology. Describe each level.
Organisms (one individual that has all the characteristics of life)
population (a group of organisms)
community (and collection of populations)
ecosystem (several communities including the abiotic components of the environment)
biome (a group of similar ecosystems)
biosphere (the livable portion of the planet)
5. Define habitat.
The place where an organism lives
6. Define niche.
The role an organism plays in its environment including all of the biotic and abiotic needs for
survival.
7. If organisms have overlapping niches, what is a likely outcome of their interaction?
One organism will likely drive the other out of the area
8. Describe commensalism and give an example of commensalism.
One organism benefits, the other is unaffected
Spanish moss, barnacles on a whale, burdock seeds
9. Describe mutualism and give an example of mutualism.
Both organisms benefit
Acacia tree and ants, lichens (algae and fungus)
10. Describe parasitism and give an example of parasitism.
One benefits, the other is harmed
Tapeworms, heartworms, bacteria, ticks, fleas, mistletoe
11. What two requirements does an ecosystem have?
Continuous supply of energy
A flow of energy from one population to another
12. What type of organism is capable of using and storing energy from the sun?
Autotrophs
13. How must heterotrophs obtain energy?
They must consume their food
14. How do detritivores obtain energy? Give an example of a detritivore.
They break down dead organisms and return the nutrients to the soil and water
Fungus, bacteria
15. How do herbivores obtain energy? Give an example of an herbivore.
They eat autotrophs (plants)
Cows, rabbits, vegetarians
16. How do carnivores obtain energy? Give an example of a carnivore.
They eat heterotrophs
Fox, Hawk
17. What are the two types of carnivores? Give an example of each type of carnivore.
Predators – kill their own food
Lion, fox, eagle
Scavengers – eat animals that are already dead
Vultures, hyena
18. How do omnivores obtain energy? Give an example of an omnivore.
They eat autotrophs and hetertrophs (plants and animals)
People, bears
19. What is the difference between a food chain and a food web?
Food chain is one series of trophic levels Food web is an overlapping of several chains
20. Some __________ is lost at each trophic level.
energy
21. The ultimate/primary source of energy is ___________________.
The sun
22. A rabbit eats a carrot and a fox eats the rabbit. What level consumer is the rabbit?
Primary consumer
What level consumer is the fox?
Secondary consumer
23. If the primary producers stored 1000 units of energy, how many are stored in the tertiary consumer
level?
1
24. If the primary producers stored 1000 units of energy, how many have been lost by the time you get to
the tertiary consumer level?
999
25. Why are the number of trophic levels limited?
Energy is used or lost at each level and there is only so much energy to be consumed.
26. What trophic level has the most organisms?
Producers (autotrophs)
27. What trophic level has the least number of organisms?
Tertiary consumers
28. Why would the few animals at the highest trophic level have a high concentration of a contaminant
(such as pesticides) when the food they eat from other trophic levels have lower levels?
The contaminants bioaccumulate in the bodies at each level.
29. Energy ______ through an ecosystem and Nutrients __________ in an ecosystem.
Flows, cycles
30. Where is carbon found?
Atmosphere, minerals, rocks, fossil fuels, organic materials in soil and aquatic sediments
31. Carbon is a major component in what four biochemical compounds in our body?
Proteins, carbohydrates, lipids, and nucleic acids
32. List and describe the four ways organisms play a role in the carbon cycle.
Photosynthesis - Autotrophs take in carbon dioxide from the atmosphere and convert it to
simple sugars.
Respiration - Organisms break down glucose and carbon is released into the atmosphere as
carbon dioxide.
Decomposition - When organisms die, decomposers break down carbon compounds which
both enrich the soil or aquatic sediments and are eventually released into the atmosphere as
carbon dioxide.
Conversion of biochemical compounds - When animals eat carbohydrates, proteins, lipids,
and nucleic acids, those compounds can be:
– used for energy
– converted to compounds that are suited for the predator’s body
– released to the atmosphere as methane and other gases
33. How does combustion play a role in the carbon cycle?
When wood or fossil fuels (which were formed from once living organisms) are burned,
carbon dioxide is released into the atmosphere.
34. Where is nitrogen found?
atmosphere, living organisms, or in organic materials in soil and aquatic sediments.
35. Nitrogen is a major component in what biochemical compounds in our body?
amino acids which are needed to build proteins
36. List and describe the four ways organisms play a role in the nitrogen cycle.
Nitrogen-fixation - Nitrogen-fixing bacteria in the soil, root nodules of plants, or aquatic
ecosystems convert nitrogen in the air or water into forms that plants can use.
Intake of nitrogen into the organisms - Plants take in the nitrogen through their root systems
so nitrogen can enter the food chain.
Decomposition - When an organism dies or from animal waste products, decomposers return
nitrogen to the soil.
Denitrification - Denitrifying bacteria break down the nitrogen compounds in the soil and
release nitrogen into the atmosphere.
37. Where are four places water is found?
atmosphere, on the surface of Earth, underground, and in living organisms
38. The process of ______________ moves water from lakes, rivers, and oceans to the atmosphere.
evaporation
39. The process of ______________ leads to the formation of clouds.
condensation
40. The process of ______________ returns water to the bodies that store it.
precipitation
41. List and describe the four ways organisms play a role in the water cycle.
Intake of water into the organisms: Organisms take in water and use it to perform life
functions
Transpiration: Plants release water back into the atmosphere
Respiration: All organisms metabolize food for energy and produce water as a by-product of
respiration.
Elimination: Most organisms need water to assist with the elimination of waste products.
42. What is a biosphere and what are the three parts that make it up.
Atmosphere, Hydrosphere, Geosphere
43. What is the greenhouse effect? How do people, carbon dioxide and plant life play a role in the
greenhouse effect?
the normal warming effect when gases (such as carbon dioxide, oxygen, methane, and water
vapor) trap heat in the atmosphere.
Plants help take carbon dioxide out of the atmosphere – fewer plants means more CO2 in the
air
People can contribute to the CO2 in the atmosphere – more Co2 means a greater greenhouse
effect and higher temperatures
44. What is succession?
Natural changes and species replacements in communities of an ecosystem
45. When organisms colonies new areas (that have never had life) it is called _________________.
Primary succession
46. The first species to populate an area is called the ________________.
Pioneer species
47. The mature community that is developed after community becomes stable is the ______________.
Climax community
48. When organisms colonize an area that once had life that was wiped out is called_______________.
Secondary succession
49. One of the main differences in secondary succession is that the community already has _________.
soil
50. Populations growing with no limitations show a ___________ shaped curve called ____________
growth.
J, exponential
51. What is carrying capacity?
The number of organisms an environment can support for an indefinite period of time
52. If you had an aquarium, how could you increase the carrying capacity? How could you decrease it?
Increase – add more food, get a bigger tank
Decrease – give them less food, use a smaller tank
53. A population that has grown to its carrying capacity forms a ______ shaped curve.
S
54. List and define the two types of environmental limitations?
Density-Dependent, Density-Independent
55. Give an example of a density-dependent factor.
Disease, Competition, Parasites, Predation
56. Give an example of a density-independent factor.
Temperature, storms, natural disasters, drought, habitat destruction, pollution
57. How does population size of both predators and prey affect each other?
The number of predators affects the prey population
More predators, more risk to prey
The number of prey affects the predator population
More prey, more food for predators
58. List several positive and negative effects population growth and technology have on our environment.
Population Growth
Positive – more minds to help come up with solutions
Negative – increased use of limited resources, more waste and pollution
Technology
Positive – new methods of farming, energy, or transportation that may conserve soil,
water or other resources
Negative – new technologies may produce more pollution or waste
59. How can we lesson the negative effects that human population growth can have on the environment?
Reduce, Reuse, Recycle