KEY
Exam 5 Study Guide: Ecology
1.
Energy FLOWS (flows or cycles?) in our environment
2.
In terms of energy, Earth is an OPEN (open or closed?) system.
3.
What is the formula for photosynthesis and what is the organelle that performs it:


4.
CO2 + H2O + sunlight  C6H12O6 + O2
chloroplast
What is the formula for cellular respiration and what is the organelle that performs it:


C6H12O6 + O2  CO2 + H2O + ATP (energy)
mitochondria
5.
Photosynthesis is performed by PRODUCERS/
AUTOTROPHS. These include plants, some algae, and some bacteria.
6.
An organism that gets its energy by eating other organisms is a CONSUMER/ HETEROTROPH.
7.
Herbivores eat PLANTS/PRODUCERS. An example is HORSES,
COWS, MOOSE, ETC.
8. Carnivores eat ANIMALS/ CONSUMERS. An example is CATS, WOLVES, SHARKS, ETC.
9.
Omnivores eat PLANTS
& ANIMALS. An example is HUMANS, BEARS, ETC.
10. Decomposers, which include bacteria and fungi, get energy from
BREAKING DOWN DEAD PLANTS & ANIMALS.
11. Each step in a food chain is called a trophic level. Producers are the first level. The herbivores that eat the producers are called PRIMARY
consumers. The carnivores that eat these are called SECONDARY consumers.
12. Why is the energy flow up the food chain depicted as a pyramid (i.e., how much energy is available to the next trophic level?): ONLY 10%
OF ENERGY IS AVAILABLE TO THE NEXT TROPHIC LEVEL – DECREASES BY 90% EACH STEP
13. If the producers in an ecosystem capture 1000 units of energy, how many units are available to the primary consumers?
100
14. If the producers in an ecosystem capture 5000 units of energy, how many units are available to the secondary consumers?; tertiary consumers?


50
5
15. What is a niche? THE
16.
UNIQUE ROLE THAT AN ORGANISM PLAYS IN ITS ECOSYSTEM
COMPETITION is a relationship in which different individuals or populations attempt to use the same limited resource.
17. What is symbiosis? RELATIONSHIPS IN WHICH 2 SPECIES LIVE IN CLOSE ASSOCIATION
18. Contrast the following in terms of whether organisms are benefitted, harmed, or are neutral.
o
Mutualism:
o
Commensalism:
o
Parasitism:
BOTH BENEFIT (+, +)
ONE BENEFITS, ONE NEUTRAL (+, 0)
ONE BENEFITS, ONE HARMED (+, -)
19. Name an example of mutualism: SEA
ANEMONE & CLOWN FISH; CLEANER FISH & SHARK; POLLINATORS
& PLANTS
20. Name an example of commensalism: BARNACLES & WHALES; CATTLE EGRETS & COWS
21. Name an example of parasitism: COWBIRD & OTHER
BIRDS (BROOD PARASITISM); MOSQUITOES &
OTHER ANIMALS; TICK & HOST
22. Do parasites have to have a host? NO
23. What are keystone species? Give examples. SPECIES THAT HAVE A LARGE EFFECT ON OTHER SPECIES &
BIODIVERSITY
 EXAMPLES: ALLIGATORS, SEA OTTERS, GRAY WOLVES
24.
INDICATOR species provide early warning of damage to a community or ecosystem. Good examples are frogs, butterflies, and aquatic
insects.
25. Beavers, alligators, and elephants are examples of FOUNDATION species that create or enhance their habitats, which benefit others.
26. Carbon cycle: Carbon is cycled between plants, animals, and the atmosphere during these two processes:


PHOTOSYNTHESIS
CELLULAR RESPIRATION
27. Carbon dioxide is increasing in our atmosphere due to burning of FOSSIL FUELS.
28. What does extra CO2 in our atmosphere cause? EXTRA
GAS MOLECULES TRAP HEAT IN THE ATMOSPHERE *
WARMS THE EARTH
29. Name 2 ways can you reduce your carbon impact. DRIVE LESS,
DRIVE HYBRID CARS, USE LESS PLASTIC, EAT
LOCAL FOOD
30. Oxygen cycle: Oxygen is cycled between plants, animals, and the atmosphere during these two processes:
o
o
31.
PHOTOSYNTHESIS
CELLULAR RESPIRATION
OZONE (O3) in the upper atmosphere protects us from UV rays.
32. Nitrogen cycle: what type of organism performs the important role of changing the form of nitrogen from atmospheric nitrogen (N 2) into forms
that can be used by plants & animals (nitrates – NO3)? BACTERIA
33. What important biological molecules do we use nitrogen in? PROTEINS
AND NUCLEIC ACIDS (DNA)
34. What human activity is adding nitrogen to the environment? What problems do this cause?


USING FERTILIZERS AND BURNING FOSSIL FUELS
ACIDIFICATINO OF LAKES & RIVERS; GLOBAL WARMING; ALGAL BLOOMS
35. Water/ Hydrological cycle: what process turns ocean water into water vapor? EVAPORATION
36. Water/ Hydrological cycle: what process turns water vapor back into liquid? CONDENSATION
37. Water/ Hydrological cycle: what process is where liquid water falls back to earth in the forms of rain, snow, sleet, etc.?
38. How does water inside plants & animals return to the environment? TRANSPIRATION &
PRECIPITATION
RESPIRATION & WASTE
39. Phosphorus cycle: the cycle begins when ROCKS erode, putting phosphate into the soil and water.
40. What important organic molecules do we use phosphorus for? ATP
& Nucleic Acids (DNA)
41. What does excess phosphorus from fertilizers do in the environment? CAUSES EXCESS PLANT & ALGAE GROWTH
THAT CAN CAUSE FISH & OTHER ORGANISMS TO DIE (SUFFOCATE)
42. Sulfur pollution from factories makes sulfuric acid, which creates ACID
RAIN
43. In terms of matter (i.e., nutrients), is Earth an open or closed system? CLOSED This is according to the Law of
OF MATTER.
CONSERVATION