APES / IBESS
NAME:____________________________Block: ___
Raven & Berg HW Ch. 4
CHAPTER OUTLINE:
I. Introduction to ecology
A. Terms and definitions
B. Hierarchy: population, community, ecosystem,
biosphere
II. Energy: Basic principles and biological processes
A. Introduction and definitions
B. Two laws of thermodynamics and their
application to living systems
C Photosynthesis, primary productivity in the
deep sea (chemosynthesis), and cellular
respiration
1. Chemical equations
2. Relationship to basic laws of
thermodynamics
III. Food chains and food webs
A. Energy flow and trophic levels
B. Ecological pyramids: numbers of organisms,
biomass, and energy
C. Primary productivity
1. Gross primary productivity
2. Net primary productivity
D. Human impact on food webs.
1. An example: Antarctic food webs
2. Commercial fishing practices
3. Impact of management practices – an
example
4. Human appropriation of NPP
IV. Ecosystem Calculations
CHAPTER QUESTIONS TO CONSIDER
1. Put the following terms in order from smallest to largest: ecosystem, population, species, community, and biosphere.
2. What is the difference between a community and an ecosystem? Between an ecosystem and a landscape?
3. Briefly summarize the first and second laws of thermodynamics and then explain how each is applicable to the study of ecosystems
and energy.
4. Define entropy and briefly explain how it relates to the continual energy needs of organisms.
5. Briefly explain the process of cellular respiration and list three examples of organisms that use it. Your answer should include the
following terms: glucose, water, carbon dioxide, energy, and oxygen.
6. Compare and contrast the processes of cellular respiration and photosynthesis. Be sure to include balanced chemical equations as
part of your answer.
7. Briefly discuss the role of autotrophs in an ecosystem.
8. Define detritivore and provide two examples. Which category do these organisms belong in based on their means of obtaining
nourishment?
9. Discuss the contributions of saprotrophs, detritivores, and autotrophs to a balanced ecosystem. Identify two representatives of
each group in your discussion.
10. Compare and contrast the following terms: food chain and food web.
11. Why is the concept of a food web generally preferred over that of a food chain?
12. Compare and contrast the three different types of ecological pyramids. Use sketches of each type of pyramid with associated
quantitative units to support your comparison.
13. Are the following balanced ecosystems? Be able to explain your reasoning!
A. Producers & Consumers
B. Consumers & Decomposers
C. Producers & Decomposers
14. Draw a food web containing organisms found in a Chesapeake Bay salt marsh. (look at page 63)
15. Explain why only about 10% of the energy is passed on as energy moves from one trophic level to another. Use a food chain from
an ecosystem of your choice starting with an energy value of 1,000,000 units to support your explanation.
16. Suggest a food chain that might have an inverted pyramid of numbers- that is, greater numbers of organisms at higher trophic
levels than at lower trophic levels.
17. Is it possible to have an inverted pyramid of energy? Why or why not?
18. Relate the pyramid of energy to the second law of thermodynamics.
19. How are the following forms of energy significant to organisms in ecosystems? A. Radiant B. Mechanical C. Chemical D. Heat
20. The NPP for a particular river ecosystem is measured at 8,833 kcal/m2/year. Respiration by the aquatic producers is estimated
as 11,977 kcal/m2/year. Calculate the GPP for this ecosystem.
21. Know and apply the appropriate formulas to solve for NPP, NEP, R (Rc & Rp), %Trophic Level Efficiency, % Growth Efficiency.