Exam 2 - 2010-Spring-key

# Exam 2 - 2010-Spring-key - Your code: KEY Page 1 of 12 THIS...

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Your code: K EY Page 2 of 12 2-1. A student doing an independent project (Zoo 4905) monitored Daphnia growth in a lake, and based on their performance was able to describe how the per capita growth rate varied as a function of density. Her data are shown below. -0.4 -0.2 0 0.2 0.4 0 2 4 6 8 10 12 14 Per Capita Growth Rate, dN/Ndt (per week) Daphnia Density (no. / 10 ml) a) (4 points) Given enough time, to what density will the population converge if initiated at the following densities: Final Density N 0 = 1 0 N 0 = 3 11 N 0 = 7 11 N 0 = 14 11 b) ( 2 points ) Give a biologically plausible explanation for this hump-shaped function (your answer must be sufficiently complete to explain both the rise and fall of the curve). Initial increase: Allee affect due to Type II functional response (e.g., due to handling time) or social facilitation of reproduction or feeding. Eventual decrease: Intraspecific competition, aggregation by predator, increased incidence of disease
Your code: K EY Page 3 of 12 3-1. (2 points) Dr. I.M. Green monitored a plant population’s density through time (note the logarithmic scale): 1 10 100 1000 01234567891 0 Density time (years) Over which time period does the plant population exhibit the greatest per capita growth rate ( circle the correct option )? i. 0-3 yrs ii. 3-6 yrs iii. 7-10 yrs iv. The answer can’t be obtained from the data available 3-2. The dynamics of three species can be described using the following equations (where N is density, in no./m 2 ): dN 1 /N 1 dt = +1.0 – 0.1N 1 – 0.1N 2 dN 2 /N 2 dt = +0.6 – 0.2N 1 – 0.2N 2 – 0.1N 3 dN 3 /N 3 dt = –0.1 + 0.1N 2 For each of the following, choose (i.e., circle ) the best option from the those available within parentheses: a) (1 point) Species 1 and 2 are: ( competitors; predator and prey; mutualists, do not interact directly ) b) (1 point) Species 1 and 3: ( competitors; predator and prey; mutualists, do not interact directly ) c) (4 points) In the absence of Species 3, Species 1 and 2 will: ( both persist; only species 1 will persist; only species 2 will persist; neither will persist; there is not enough information provided ) hint: for c) apply the concept of invisibility.

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Your code: K EY Page 4 of 12 4-1. The following life cycle diagram is based upon a time interval of one year.
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## This note was uploaded on 06/04/2011 for the course PCB 4043 taught by Professor Osenberg during the Spring '10 term at University of Florida.

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Exam 2 - 2010-Spring-key - Your code: KEY Page 1 of 12 THIS...

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