Biology
Ch. 3 The Biosphere
Name _________________________
Per. _________
California State Standards covered by this chapter:
Ecology
6. Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept:
a. Students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of
habitats.
b. Students know how to analyze changes in an ecosystem resulting from changes in climate, human activity,
introduction of nonnative species, or changes in population size.
c. Students know how fluctuations in population size in an ecosystem are determined by the relative rates of
birth, immigration, emigration, and death.
d. Students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the
ecosystem and how oxygen cycles through photosynthesis and respiration.
e. Students know a vital part of an ecosystem is the stability of its producers and decomposers.
f. Students know at each link in a food web some energy is stored in newly made structures but much energy is
dissipated into the environment as heat. This dissipation may be represented in an energy pyramid.
Read the appropriate section in the textbook and lecture notes before answering the following
questions. You must put all answers and definitions into your own words for full credit.
3-1 What is Ecology?
1. Ecology:
2. What is the biosphere?
3. Ecologists study how organisms interact with their environment at several levels. Describe
what they study at each of the following levels.
Species
Population
Community
Ecosystem
Biome
4. What are the three basic approaches scientists use to conduct modern ecological research?
a.
b.
c.
5. Why might an ecologist set up an artificial environment in a laboratory?
6. Why are many ecological phenomena difficult to study?
7. Why do ecologists make models?
3-2 Energy Flow
8. What is the primary source of energy for life on Earth?
9. Autotroph:
10. Why are autotrophs also called producers?
11. Photosynthesis:
12. Chemosynthesis:
13. Where do bacteria that carry out chemosynthesis live?
14. For each of the following, write which kind of autotroph is the main producer.
a. Land:
b. Upper layers of ocean:
c. Tidal flats and salt marshes:
15. Heterotrophs:
16. Why are heterotrophs also called consumers?
17. There are many different types of heterotrophs. Complete the table.
Consumer type
Definition
2 Examples
a. Herbivore
b. Carnivore
c. Omnivore
d. Detrivore
e. Decomposer
18. How does energy flow through an ecosystem?
19. What is a food chain?
20. What is a food web?
21. What is a trophic level?
22. In a food web, what organisms make up the first trophic level?
23. What is an ecological pyramid?
24. Why is it that only part of the energy stored in one trophic level is passed on to the next level?
25. What is biomass?
26. What does a biomass pyramid represent?
27. What does a pyramid of numbers show?
28. A food web is a complex network of feeding relationships. Each step in a food web is called a
trophic level. Producers are the first trophic level.
Color the organisms in each
trophic level. Follow the
prompts below.
• Color the producer(s)
green.
• Color the first-level
consumer(s) brown.
• Color the second-level
consumer(s) blue.
• Color the third-level
consumer(s) purple.
29. Using the diagram above, write one food chain starting with marsh grass.
Marsh grass →
3-3 Cycles of Matter
30. Biogeochemical cycles:
31. How is the movement of matter through the biosphere different from the flow of energy?
32. What do biogeochemical cycles connect?
33. The water cycle is the movement of water between the ocean, the atmosphere, land, and living
things. The processes involved in the water cycle are labeled A-G in the diagram. Identify the
process and describe the process in the table below.
Process
A.
B.
C.
D.
E.
F.
G.
34. Nutrients:
Description
35. Which processes release carbon into the atmosphere? Describe them.
a.
b.
c.
36. What process removes carbon from the atmosphere? Describe it.
37. What biological macromolecules contain carbon?
a.
b.
c.
d.
38. By which process do certain bacteria convert nitrogen gas into ammonia (NH3)?
39. What form of nitrogen is useful to producers?
40. What process puts nitrogen back into the atmosphere?
41. Nitrogen is required to make what type of macromolecules?
42. What macromolecules is phosphorus essential for making?
43. Where is most of the biosphere’s phosphorus stored?
44. What process releases phosphorus from rocks and sediments?
45. Primary productivity:
46. Explain how a nutrient can be a limiting factor in an ecosystem.
47. How does an algal bloom disrupt the equilibrium in an aquatic ecosystem?