Exam 7 Part 1: Ecology Intro, Population Ecology, Community Ecology
1. The specific region of the universe where we know life to exist is the:
a) Earth
b) Biosphere
c) All land, water and atmosphere of Earth
d) Ecosystem
2. What are the two types of factors that define an environment, limit the distribution of a species and determine the
abundance of a species?
 Biotic

Abiotic
3. Determine which of the following is an example of an abiotic or biotic component? ( Fill in the letter ‘A’ for abiotic,
and ‘B’ for biotic)
_A_ The amount of light that reaches the different depths of the ocean.
_B_ The bubonic plague which swept through Europe in the 14 th century killing millions.
_A_ The salinity of certain aquatic environments determining which species can survive in that environment.
_B_ The competition seen between two different species of bird for a particular nesting space.
4. The maximum number of individuals a certain area can sustain is known as:
a. the intrinsic rate of growth.
b. the resource limit.
c. the carrying capacity.
d. the logistic equation.
e. the equilibrium size.
5. What are three strategies used to estimate the size of non-human populations? List them below.
 Direct counting
 Random sampling
 Mark-recapture
6. What are the three patterns of population dispersion?
 Clumped
 Uniform
 Random
7. Which of the three patterns of population dispersion demonstrates positive interactions and what are the benefits?
Clumped – protection, reproduction, social structure, habitat variability
8. Which of the three patterns of population dispersion demonstrates negative interactions and what are some of the
reasons for following this pattern?
Uniform – competition for limited resources, direct antagonism (territorial animals)
9. Which of the three patterns of population dispersion demonstrates a lack of strong intra-population interactions?
List examples of intra-population interactions.
Random- spread of disease, mating, nurturing, hunting, social interaction
10. What kind of population dispersion do humans follow?
Clumped
11. Define the following terms of population dynamics.
 Demography – The study of factors that control population size
 Population Growth – Is due to births and immigration
 Population Loss – Is due to death and emigration
12. Population growth can either be:
a) Exponential or Linear
b) Linear or Logistic
c) Logistic or Sigmoidal
d) Exponential or Logistic
13. Sketch a graph of each kind of population growth model. Use years as your x-axis and population size as your yaxis.
14. What kind of population growth model are humans in right now?
Exponential
15. What are the 5 primary levels at which ecology is commonly studied? List and briefly describe each.
Organismal, population (group of individuals of same species), community (groups of species in a particular area),
ecosystem (communities together with abiotic factors), global
16. What is a biological community?
Consists of all species that interact in a certain area- includes all animals, fungi, bacteria, and other living things not
seen with the naked eye
17. What is the diversity and abundance of a species in a community dependent on?
a. Topography
b. Abiotic and biotic factors
c. Historical features- what other living organisms are near or close by
d. All of the above
18. Define the competitive exclusion principle, and provide an example:
2 species with exactly the same requirements (same niche) cannot live together in the same place; one species will
be slightly “better” at something (obtaining food, reproducing, etc.)
19. The fundamental niche is the total environmental space in which a species can exist.
a. True (The Realized niche is the actual environment in which a species does exist)
b. False
20. When a species uses other living organisms as a source of food, it is said that they:
a. Predate
b. Consume
c. Live in separate niches
d. Are mutualistic
21. List some ways that animals defend against predators, and provide examples:
a. Mimicry- moths look like=bees=wasps=beetles
b. Herbivory- plants producing spines and poisons and thorns to protect themselves
22. Next to each phrase, write either P for parasitism, M for mutualism, Pa for parasitoids, or C for commensalism.
_____ If this particular relationship tips in either direction, it ca develop into mutualism or parasitism C
_____ Both species benefit from the interaction M
_____ Humans and most of our gut microbes share this kind of interaction (M or C)
_____ This interaction benefits one organism at the expense of the host organism, and the host organism usually
lives P
_____ This interaction benefits one organism at the expense of the host organism, and the host organism usually
does not live Pa
_____ A tick sucking the blood of a human is an example of this interaction P
_____ One species benefits, while the other is neither negatively or positively affected C
23. Species of animals present in environments that are undergoing succession do not change as succession
proceeds.
a. True
b. False (They do change and adapt to the new abiotic environment)
24.
Presence of
macroscopic life?
Example of scenario
environment
Are the effects of
organismal growth
permanent in the
environment?
Primary Succession
No
The terrain after a glacial
retreat; surface of lava flow
No- succession will start
again after the next
environmental disturbance
Secondary Succession
Yes
An agricultural field that is no longer farmed; or some
other disturbance-induced (fire) event that wipes out
a once thriving area
No- succession will start again after the next
environmental disturbance
25. Immigration rates _____________ (decrease/increase) as species richness ____________ (decreases/increases).
26. The above statement is true because (look to Fig 55.22 for more information):
Competition and new immigrants are ALREADY members of already established species
27. Species richness depends on the longitude of their location on Earth.
a. True
b. False (latitude- but we’re not too sure why that is)
Terms to know:
1.) Population
2.) Intra-specific interactions
3.) Inter-specific interaction
4.) Clumped dispersion
5.) Uniform dispersion
6.) Random dispersion
7.) Demography
8.) Population Growth
9.) Population Loss
10.) Exponential Growth Model
11.) Growth rate (r)
12.) Logistic Growth Model
13.) K
14.) Density-Independent Mortality Factors
15.) Density-Dependent Mortality Factors
16.) Logistic Growth Model
17.) Population Cycles