BIOL 170 Exploring Biology
Dr. George Davis
Ecology Unit Outline with Review Questions
Fall 2008
Note: All section numbers refer to main text: Essentials of the Living World, 2nd edition. Johnson
and Losos, 2008. Parts of chapters 20-21.
Earth’s Climate: What Affects It?
I.
Earth’s Size and Location
A. Size and shape
B. Location and distance from the sun
II.
Revolution of the earth
A. Shape of the earth’s orbit
B. Period of rotation: 1 year
III.
Seasons (Johnson and Losos, section 20.6)
A. The cause of the seasons: tilt of the Earth to the plane of orbit (23.5 degrees)
B. Progress of the earth’s seasons
C. Changes in the amount of sunlight
D. Climate zones
IV.
Earth’s surface
A. Land/water percentage
B. Water’s unique properties
1. Water has a high specific heat as compared to the land
2. Water molecules move apart when they change from a liquid state to a solid
state: ice is less dense than liquid water, therefore, ice floats in liquid water.
C. Why waters properties are important
D. Ocean Currents (20.8)
Review Questions:
1. Why is it hot in the July and cold in January each year in Moorhead, MN?
2. Where on the earth is the sun directly overhead at noon on March 21st and
September 23rd?
3. Why is it often colder during winter in northern Minnesota than it is in many parts
of Norway?
Biomes and Ecosystems
I. Biomes (land only) (21.7+20.11)
A. Tropical Savanna
B. Tropical rainforest
C. Temperate grassland
D. Temperate deciduous forest
E. Boreal Coniferous forests
F. Desert
G. The three main biomes in North America
H. The three main biomes in Minnesota
Review Questions:
4. Give two significant differences between a temperate grassland and a savanna.
5. a. What biome has the most diverse group of species of any terrestrial biome on
earth?
b. Such diversity affects the size of the population of each species how?
6. Why did the middle U.S. biome change to grassland after the uplift of the Rocky
Mountains?
7. Why does the air temperature change so greatly from heat of the day to the cool of
the night in a desert biome?
8. Why does the deciduous forest so dominate the eastern United States while the
conifer forest biome’s southern boarder is limited to Canada, northern boarder
states of US and higher elevations of mountains?
II. Ecosystem function
A. Niches and habitats (21.5+21.6)
B. Trophic levels in a community (20.1)
C. Energy flow through an ecosystem (20.1)
D. Food webs/niches and habitat (using a tallgrass prairie community as an example)
(20.1)
E. Ecological pyramids: energy transfer through trophic levels (20.2)
F. Kinds of organism interactions (21.7+21.8+21.9)
F. Materials cycle in an ecosystem
1. The carbon cycle (20.4)
2. The Hydrologic (water) cycle (20.3)
G. Succession (21.11)
Review Questions:
9. What is the most unique function of the producers (1st trophic level) in an
ecosystem?
10. Humans are examples of omnivores. Explain why this term is appropriate for
humans.
11. There is no waste in an ecosystem. What class of consumers deal with the
organic waste normally produced in a natural ecosystem?
12. Why does it take so much biomass at the lower trophic level to support biomass at
a higher trophic level?
13. Why is it more likely that a biome or ecosystem can support large numbers of
herbivores but not large numbers of carnivores?
14. Identify the type of organism interaction for each of the following:
A. rabbit and fox
B. vine on basswood tree
C. moss on a tree
D. flower and a bee
15. Where is most of the carbon dioxide found on the earth?
16. What is the most common gas in the earth’s atmosphere?
17. What is the energy source that drives the water cycle?
18. What is the difference between the pioneer stage and the climax stage in
ecosystem development?
19. Define the following terms:
a. Trophic level
b. Niche
c. Habitat
d. First order consumer
e. Second order consumer
f. Third order consumer
20.Why is a farm field in the spring an example of secondary succession?