Second Exam: March 26, 1999 Name _____________________________

DIRECTIONS: answer each question by filling in the blank, writing a short response, etc. Multiple choice are worth 2 pts. each; points possible are stated in the other questions.

Matching: 20 @ 2 pts. each

___ 1. Lakes or ponds are these type of aquatic systems

___ 2. Wooded wetland (has trees or shrubs)

___ 3. Wetland with herbaceous plants (grasses, cattails, etc.)

___ 4. Area of land draining into a given water body

___ 5. Increased productivity of a water body, caused by nutrients added by humans

___ 6. Area of land with elevation only slightly higher than the stream bank

___ 7. Formed after river changes course; remnant of a meander

___ 8. Plants at greater depths than this, use energy faster than is captured by photosynthesis

___ 9. Little or no oxygen in water, often due to depletion by microbial decomposers

___ 10. Birth/germination of new individuals

___ 11. All of plant body which grew from one fertilized egg (e.g., from one seed)

___ 12. All individuals which can interbreed (even if spatially removed from each other)

___ 13. All individuals born in a particular time period (such as a breeding season)

___ 14. Individual flower is perfect, or individual animal with both male and female gonads

___ 15. Individuals are male or female, not both

___ 16. Deepest part of the lake is this zone

___ 17. Part of the lake near shore

___ 18. A dissolved gas, often found in low quantities in water, and found only in acidic water

___ 19. Carbon dissolved as ion in water; can be used for photosynthesis

___ 20. crust found on plants growing in hard water, is made of this material

Possible answers (none are used twice; not all will be used):

a. natality n. marsh

b. cohort o. swamp

c. littoral p. genet

d.limnetic q. ramet

e. benthic r. gene pool

f. lotic s. metapopulation

g. lentic t. monoeicous

h. compensation depth/point u. dieciuos

i. cultural eutrophication v. hermaphroditic

j. watershed w. calcium carbonate

k. flood plain x. free CO₂

l. oxbow lake y. bicarbonate

m. anoxia z. hydrocarbons

21. Which best describes a first-order stream?

a. Only flows after rains, otherwise dry

b. drains directly into the ocean

c. headwaters of a larger stream/river

d. has high primary productivity

22. what is an ecotone?

a. ecosystem protected by law

b. ecosystem which is quite stable

c. measure of biogeochemical dynamics

d. transition zone between two types of ecosystems

23. Wetlands attenuate floods by…

24. Which of the following is true about Dissolved Oxygen (DO) in a stream?

25. An age pyramid describes…

a. how many individuals in a population, are in each age class

b. how many individuals in a population died at each age

c. how much is used by organisms in each age class

d. whether the population is r or K selected

26. The Shannon-Weaver index was developed from work in what discipline?

a. Energy transfer (thermodynamics)

b. Information theory (communications)

c. Economics (competition)

d. Natural resources (forestry)

27. Which of the following is clearly a density-independent factor regulating population growth?

a. competition for food and raw materials

b. activities of predators

c. disease

d. climate

28. Nitrogen is added to an ecosystem in a natural process (fixation) associated with…

a. microbes in the roots of grasses

b. microbes in the roots of legumes

c. microbes on the surface of leaves

d. bottom sediments of lakes

29. Mineralization (or ammonification) of nitrogen is best described as

a. converting N2 gas into organic N

b. converting NO3 into organic N

c. converting organic N into ammonia

30. (6 pts.) Fill in the table below, supplying characteristics for the two life history strategies:

r - selected species K - selected species

stability of environment

in which often found

competitive ability

reproductive strategy

31. (8 pts.) Give the equation for the Logistic growth model. Define each of the terms (variables, constants), and its biological meaning. Draw a graph showing logistic growth.

32. (7 pts.) Draw graphs (using proper limnology format) of temperature vs depth in (a) summer and (b) autumn, for a natural lake in Iowa. Briefly interpret the graphs.

33. (4 pts.) Draw survivorship curves for (a) humans and (b) salmon, indicating the type of survivorship (I, II, or III) in each.

34. (5 pts.) Briefly describe aquatic productivity in the context of the "River Continuum Concept": what is the source of productivity, and the nature of biogeochemistry in the stream/river?

35. (6 pts.) Wetlands remove nitrogen pollution from water. What form of nitrogen is the usual pollutant? How do wetlands remove the nitrogen (describe the mechanism).

36. (6 pts.) Briefly describe the antlers (rack) of the Irish Elk and their significance to the organism. Why would having such a seemingly counterproductive structure, actually increase fitness of an individual? What is the term for the type of evolutionary process causing this adaptation?