# Ecology Test IX

Bio-geochemical Cycles
Quiz I

Ecosystem
Problem set I

Ecology Test
Test 1   Test 2
Test 3   Test 4
Test 5   Test 6
Test 7   Test 8
Test 9   M/C

Energy Calculation
Quiz 1   Quiz 2

Human Ecology
Quiz 1   Quiz 2
Quiz 3

Population Dynamics
Quiz 1   Quiz 2
Quiz 3   Quiz 4
Quiz 5   Quiz 6
Review

Part A: Easy Stuff.  Answer Part “A” on this page please.  Each is marked out of 5, but all these questions are only 32% of the total paper.

1.      The five processes are into which sunlight goes when it hits the earth are ...

2.      Three traits of an r-selecting species are …

3.      Three traits for a k-selecting species are …

4.      Three density-independent population regulators are …

5.      Three factors which regulate human population are …

6.      Three sources, processes, and sinks found in the sulfur cycle are ...

 Source Process Sink

7.      Three sources, processes, and sinks found in the nitrogen cycle are ...

 Source Process Sink

8.      Are density-dependent regulatory factors biotic in character, abiotic, neither or both?  Explain.

Part B: Straight Calculations. Please answer these on lined paper. Each is marked out of 5, but all these questions are only 32% of the paper.

1.      In order to estimate the population of turbot off the east coast of Newfoundland, 20,000 turbot were captured and tagged with metal strips in their fins.  The very next day fish were captured in two batches.  The first batch had 1000 fish in total, 100 of which had tags.  The second batch had 750 fish, 150 of which had tags.

a)      According to these figures, how many turbot are there?  (Show your calculations!)

b)      Is this a "good" estimate of the fish population? Explain.

2.      A student has been sampling the test-tubes containing an algal culture s/he is growing. Over the last 8 weeks, the results were:

Table 1 : Student Data for Algal Culture

 Weeks since start Population (cells per medium view) 1 3 2 4 3 6 4 8 5 12 6 5 7 23 8 30

When should the population density reach 60 cells per medium view?  Show your calculations and work.

Part C: Calculations and Synthesis. Please answer these on lined paper. Each is marked out of 5, but all these questions are only 40% of the paper.

1.       The following food web or food chain was found to exist in a stretch of the Thames river running from the Adelaide St. Bridge to Highway 4: colpodia (single-celled animals), trout fish, hydra (multi-cellular animals almost visible to the naked eye, algae (a single celled plant), darters (a kind of minnow), caddis-fly larvae (which are about 2 to 5 mm big).

a)      Sketch a likely food pyramid.  Label it with the names of the organisms.  If there are places where you have to make assumptions, tell me what the assumptions are.

b)      The total amount of energy made by the plants was found to be 1,000 kJ per week per 200 m2 of surface area. Make a pyramid of energy showing the amounts of energy which exist at each stage. State any assumptions or approximations.

c)      Show on the pyramid where we would likely find organisms that are primarily regulated by over-crowding.

d)      Show on the pyramid where we would likely find organisms that are primarily regulated by temperature fluctuations.

e)      How do the Laws of Thermodynamics apply to these ideas addressed in this question?

f)       Is this a closed system, open system, sort of  both or neither.  Argue your case, and be specific.

2.       Dr. Poulet Petite is a scientist who claims that CO2 emissions are at “alarmingly high levels and increasing more and more” and that if everything continues that way, “we’re all in big trouble.”  Dr. Tina Little-Deel agrees accepts that CO2 emissions are in fact increasing, but claims that since the increase is only 0.05% per year, that there is no real need to be concerned.  Should we be concerned or not?  Why?