Chapter 13 Reading Guide
13.1 Ecologists Study Relationships
1. What is ecology?
The study of how species interact with each other and their environment.
2. Complete the table
Description
Example
Biome
Major region or global community
Savanna
Community
Multiple species in a given area
Alligators and Herons in the Everglades
Ecosystem
Organism
Everything in a community plus abiotic Alligators, Herons, and water in the
factors
Everglades
Individual thing
Alligator
Population
Group of one species in a given area
Alligators in Everglades
3. Place the terms from question #2 in order from smallest to largest.
Organism, Population, Community, Ecosystem, Biome
4. Why is it incorrect to say a population is “the number of deer” but correct to say it is “the number of
deer in Black Hawk County”?
Population must have a defined area.
5. What does an ecosystem include that a community does not?
Abiotic (non-living) factors
6. What level of organization describes all the plants, animals, and insects in Hartman Reserve Nature
Center?
Community
13.2 Biotic and Abiotic Factors
7. Define:
Biotic Living things in an environment
Abiotic Non-living things in an environment
8. Classify each of the following terms as either biotic or abiotic.
amount of sunlight Abiotic
number of insects
Abiotic
grass Biotic
amount of iron in soil Abiotic
temperature Abiotic
types of fish Biotic
9. How do abiotic factors affect biotic factors?
Things like temperature, sunlight, soil, etc. impact what species can live in a given area.
10. What is biodiversity?
Biodiversity is the variety of living things in a given environment.
11. Which type of biome is likely to have the greatest biodiversity, a desert or a temperate deciduous
forest? Explain. (Examine figure 15.7 on page 463 for a description of each biome)
Temperate deciduous forest, as the climate is less extreme.
12. Which abiotic factors most likely responsible for the high biodiversity found in the tropical rain
forests?
Climate: sunlight, temperature and moisture.
13. What are keystone species and why are they important to an ecosystem.
Keystone species have a significant impact on the success of other species in an ecosystem. Oftentimes
they change the environment making it more ideal for others to live in.
14. Internet Research. Use the internet to find an example of a keystone species and describe in detail
what might happen to the ecosystem if the keystone species is removed.
13.3 Energy in Ecosystems
15. Define:
Producers
Consumers
Autotrophs
Heterotrophs
16. What energy source do most producers use to make food? _______________________
13.4 Food Chains and Food Webs
17. Complete the table
Define
Example
Herbivores
Carnivores
Detritivores
Decomposers
18. What type of organisms are always found at the bottom of food chains?
19. Draw a food chain with at least three species.
20. What are trophic levels?
21. Complete the table of different trophic levels
Trophic Level
Description
Example
Producers
Primary
Consumers
Secondary
Consumers
Tertiary
Consumers
22. Place the following words in the correct level of the trophic pyramid
(more than one word per level)
carnivore, caterpillar, hawk, herbivore, primary consumer,
producer, robin, secondary consumer, tertiary consumer, tree,
23. Draw a food web that might exist in Black Hawk County.
Be sure to include multiple producers,
primary and secondary consumers.
24. Explain the important role that decomposers play in an ecosystem.
25. Explain the difference between food chains and food webs.
26. Why is there more energy available at the bottom of a food web than at the top?
13.5 Cycling of Matter
27. What is another name for the water cycle?
28. Describe the water cycle.
29. What is the energy source that drives the water cycle?
30. Use the terms oxygen, carbon dioxide, photosynthesis, and cellular respiration to create a diagram of
the oxygen cycle.
31. What process converts CO2 to organic carbon?
32. What processes convert organic carbon to CO2?
33. What important role do nitrogen fixing bacteria play in an ecosystem?
34. Why do farmers rotate crops, planting corn one year and beans the next?
13.6 Pyramid Models
35. The first law of thermodynamics states that energy is neither created nor destroyed, but that it
changes form. With this in mind, explain why there is less energy at each higher trophic level.
36. What is biomass?
37. What happens to the amount of biomass at each higher trophic level?
38. What happens to the number of individual organisms at each higher trophic level?
39. Explain why most food chains are limited to 5 links or less.
40. Approximately 10% of the energy available at each trophic level is passed to the next level.
A plant contains 6000 Calories of energy. The plant is eaten by an insect which is eaten by a lizard
which is eaten by a bird. How many Calories from the plant made it to the bird?