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WFSC 417/617 (Biology of Fishes)

EXAM I

SAMPLE

This exam is “closed book.” It has two parts: PART I consists of 27 multiple choice problems; PART II consists of 5 “discussion” questions. The numbered items within each part have equal value. However, you may decide, within the limits set below, the relative value of the two parts.

PART I: Eliminate any 2 of the 27 items by writing "OUT" in the answer space. (Failure to do so will automatically eliminate items 26 and 27.)

PART II: The number of questions you should answer depends on how much value (weight) you want this part to have, relative to PART I.

WFSC 417:WFSC 617:

PART II (PART I)Answer Answer

70%(30%)all 5all 5

60(40 )all 5 or any 4all 5 or any 4

50(50 )any 4any 4

40(60 )any 3 or 4any 4

30(70 )any 3N/A

Indicate your choice by circling one of the above categories. Make your decision after you have completed PART I and after you have carefully read over PART II. Mark through any PART II question(s) you chose not to answer.

Good luck!

PART I.Place the letter corresponding to the most appropriate response in the blank to the left of the lead statement or question.

1.In fishes, most digested are absorbed from the intestine, rather than from the stomach.

A.proteins

B.carbohydrates

C.fats

D.nutrients (all of the above classes)

2.The part of the visible light spectrum that best penetrates (is best transmitted by) pure water is .

A.infraredC.the middle (green-blue)

B.the red endD.the violet end

3.Polar seas tend to be less salty than the equatorial ocean because polar seas

A.are diluted to a greater degree by freshwater run-off.

B.have higher precipitation/evaporation ratios.

C.are shallower.

D.contain less fish biomass.

4.Experiments with bluegill and brown trout held at constant temperatures suggest reduction of feed intake and growth from late summer through winter. Of the following, which is most likely to be the factor responsible for the observed response?

A.barometric pressure

B.photoperiod

C.temperature

D. dissolved oxygen

5.Most ammonia excreted by fishesis actually produced in the .

A.gillsC.kidneys

B.intestinal mucosaD.thymus gland

6.In fishes, standard metabolic rate per unit fish weight (As) is typically proportional to .

A.W - 0.2C.W 0.8

B.W 0D.W 1.0

…and, on the actual exam, 21 more similar to these 6.

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PART II. Answer in the space provided.

1. a) Draw and label a graph to indicate the (approximate) relationship between concentration of dissolved oxygen (DO) and temperature for freshwater, at air saturation. Then, add to your graph the corresponding line for seawater.

b) Briefly describe the circumstances under which aquatic habitats can be under- and supersaturated with DO.

2.Consider the following data for the oxygen-dissociation curve of a fish-blood sample, where pO2 is partial pressure of environmental O2 in mmHg and BO2 is the corresponding blood-oxygen content (steady-state) in mgO2 (100 ml)-1:

pO2: 0 10. 20. 30. 40. 50. 60. 80. … 100. 150.

BO2: 0 1.8 7.0 11.3 12.8 13.4 13.7 13.9 14.0 14.0

A.What is the oxygen capacity of the blood?

B.What is the p50? ______

C.Assume pO2 is 10 mmHg in tissues and 80 mmHg in the water the fish is breathing. How much oxygen can be delivered to the tissues? _____

D.Assume a Bohr effect. Write a reasonable set of Bohr-shifted BO2 values in the space below the set given above.

E.Now, with the same pO2 assumptions as in C, how much oxygen can be delivered to the tissues? _____

Be sure your answers include relevant dimensions (“units”).

HINT: Graph BO2 vs. pO2

…and, on the actual exam, three more similar to these two.

1