Name: ___________________________
Marine Ecology-Summer 2003
Mid-Term Exam
I.
1. ___
Matching. (15 points) Match the term in the left column with the best single
definition in the right column. Please clearly right the letter of the best match
on the blank line.
A
Result of eating in cafeteria
2. ___
Produce noxious
compounds
Demography
B
Found in stable environments
3. ___
Species
C
Cafeteria food
4. ___
Abiotic condition
D
Cannibalism
5. __
Cohort
E
6. __
Resource utilization
F
Balance between mortality and fertility
schedules
The vital statistics of a population
7. ___
Emergent properties
G
Ecosystem
8. ___
Iteroparous
H
A group of genetically similar populations
9. ___
r
I
A defensive strategy against consumption
10. ___
Generalists
J
Calcium carbonate
11. ___
Competition
K
Repeated spawning
12. ___
K
L
13. ___
Cambrian explosion
M
14. ___
Community
N
A group of individuals within a population of
same age
The manner in which marine reptiles invaded
land
Spawn once and die
15. ___
Intraguild
predation
O
Point at which resources are limiting
P
Have broad niche breadth
Q
R
The shortcomings of the predictive power of
the hierarchical concept
Niche overlap
S
Niche breadth
T
Collection of interacting species
U
Rapid diversification in the ocean
V
Low oxygen
II. Short Answer. Please read and fully answer the following questions. If
necessary, you can use the back of the test.
1. Please list the four key demographic features that control organism density. A diagram
will do. (5 points)
2. Why a specialized class in marine ecology? Compare and contrast five important
differences between terrestrial (Land) and marine ecosystems (please be specific). (5
points)
Land
Sea
a)
a)
b)
b)
c)
c)
d)
d)
e)
e)
3. Please compare and contrast the two predominant forms of interspecific competition.
(5 points)
4. Early in the class I mentioned that there were a number of approaches to addressing
questions of ecological interest. I also mentioned that you needed to be aware that each
technique had its strengths and its weaknesses. Of the three techniques I listed on the
overhead, can you list two of them? No, is not an acceptable answer. Can you tell me
which of these choices provides: 1) the best opportunity to control processes of interest
and 2) which will provide the most realistic assessment of how nature is working? (5
points)
5. Define the hierarchical concepts of population and community. (5 points)
6. What is the mark and recapture technique? What is the technique used for? (5 points)
7. List three possible outcomes of intense intraspecific competition. Please be specific.
(5 points)
8. Please compare the following concepts: a) Leibig’s Law of the Minimum and b)
Gause’s Concept of Competitive Exclusion (5 points).
9. Mathematical models predict a linear relationship between prey density and the
intensity of predation. Seldom does this happen in nature? List three factors (the
functional responses described in the lecture) that reduce the rate at which
predators consume prey. Please focus on the foraging behavior of the predators, I
am not looking for aspects of prey behavior here. (5 points)
10. What is niche breadth and what is it used for? Intraspecific competition and
interspecific competition affect niche breadth in different ways. How so? (5 points)
11. Given the hypothetical example provided below, what can you say about a) the
effectiveness of your sample design in characterizing the assemblages of organisms
living in the grass and sand habitats and b) the probable structure of these assemblages in
which you collected your samples? (5 points).
A hypothetical collectors curve
50
Species Collected
40
30
20
10
0
0
1
2
3
4
Trawl Number
Grass habitat
Sand habitat
5
6
7
12. Using the method we discussed in class and lab, which column is used to develop a
population survivorship curve. Based on inspection of this data, can you predict what the
survivorship curve for this population will look like? What does this type of survivorship
curve tell you about the rate of mortality in this population? (5 points).
Age
Nx
Lx
Dx
Qx
Lx
Tx
Ex
0-1
1-2
2-3
3-4
4-5
5-6
93
74
32
14
5
1
1000
796
344
151
54
11
204
452
193
97
43
11
0.204
0.568
0.561
0.642
0.796
1.0
898
570
248
103
33
6
1858
960
390
142
39
6
1.858
1.21
1.13
0.94
0.72
0.55
6-7
0
0
0
0
0
0
0
13. Classic experiments indicate that the outcome of predator-prey interactions vary
greatly in structured and unstructured habitats. How did the results of these
experiments vary and what do they tell us about the variability in the intensity of
predator-prey interactions in nature? (5 points)
14. Please list the five steps of the scientific method (5 points).
15. Please compare and contrast the concepts of density-dependence and densityindependence. (5 points).
16. What are the key differences in the concepts of the fundamental niche and the
realized niche? (5 points)
17. What does the nearest neighbor technique measure? What are the three possible
conclusions that can be drawn from data collected using this technique (If need be, you
can provide diagrammatic examples? What can these outcomes tell us about the
interactions of organisms within a population? (5 points).
Extra Credit Questions:
a) What is a t-test? And what does it do? (2 points)