Biology (and other Life Sciences

Biology (and other Life Sciences Homework 2 Due November 13th Question 1: Life Table Analysis (5 pts) Age in mo. (X) # surviving interval lx # of offspring Fx lxFx 1 400 0 2 76 0 C 3 66 5 4 55 A 20 5 45 100 D 6 16 10 7 10 8 8 9 10 9 2 0 Total B E Fill in A-E i) A _____ ii) B _____ iii) C _____ iv) D _____ v) E ________ Question 2: Population growth/demography: The equation for logistic growth in a particular population is: dN/dt = 0.4N(1-N/100). Time is measured in months and biomass is measured in grams. The carrying capacity of the population is: (4 pts.) Question 3: Population growth/demography: The general equation for the type of population growth trajectory pictured below is: Nt = N0e rt. What is the intrinsic rate of increase of a population following this trajectory if its doubling time is 30 days? (5pts.) N Time Question 4: Population growth/demography: In the graph above, the intrinsic rate of increase, r, is greater at point A than B. (3pts. Note this question is phrased slightly differently on the on-line versus, with a different graph) a) True. b) No, r is less at A than at B. c) They are equal at A and B. d) Can’t determine without more information. A B Graphed below are the isoclines of two competing species. One of these species will eventually go extinct. Use this graph to answer the questions below. Question 5: Interspecific Competition: In which region of the graph (areas 1-4) are each of the following occurring? (4pts.) Area 1 ____ 1) both species are decreasing. Area 2 ____ 2) species 1 is increasing, species 2 decreasing. Area 3 ____ 3) species 1 is decreasing, species 2 increasing. Area 4 ____ 4) both species are increasing. Question 6: Interspecific Competition: Recalling that this is an unstable equilibrium, what are the carrying capacities and competition coefficients for species 1 and 2? (6pts.) a) K1 = 300, K2 = 200, ? =1, ?= 0.6 b) K1 = 200, K2 = 300, ? =1, ? = 2.5 c) K1 = 300, K2 = 200, ? =1.9, ? = 1 d) K1 = 200, K2 = 300, ? =1, ? = 0.6 e) none of the above Question 7: Interspecific Competition: In the absence of the other, species 1 and 2 will exhibit _______population growth. (4pts) a) random b) exponential c) logistic d) cyclical e) none of the above 200 200 300 120 1 2 3 4 0 N1 N2 Question 8: Interspecific Competition: For a particular location, two bird species (Species 1 and Species 2) are competing. For this location, we know that: K1=50, K2=20, alpha=2.00, beta=1.00 Which bird species wins the competition? (6 pts) a) species 1 b) species 2 c) they coexist d) you can’t tell, as it is an unstable equilibrium e) none of the above The oval in the graph above illustrates the cyclically changing numbers of predators and prey oscillating according to the Lotka-Volterra model. “C” represents the number of the carnivore predators and “H” represents the number of herbivore prey. Question 9: Predator-Prey Population Dynamics: In which area of the graph, indicated by the numbers 1-4, are each of the following occurring: (4pts.) Area 1 _____ 1) both predators and prey are declining. Area 2 _____ 2) the predator population grows while the prey declines Area 3 _____ 3) both the predator and prey populations are growing Area 4 _____ 4) the prey population is growing while the predator population declines Question 10: Predator-Prey Population Dynamics: In the graph above, if the intrinsic rate of increase of the prey is 1, what is the search and attack efficiency of the predator? (5pts.) a) 1 b) 0.5 c) 0.025 d) 0.1 e) none of the above Question 11: Predator-Prey Population Dynamics: Which of the following are assumptions of the predator-prey model described by the equations: dN/dt = rN-aNP and dP/dt = faNP –dP. Circle all that apply. (4pts.) a) the prey are limited by food b) predator death rate is density dependent c) prey grow exponentially in the absence of predators d) predators can consume an infinite amount of prey e) predators grow exponentially in the absence of prey WARNING: D2L randomizes the questions that call for matching (for questions 1, 5 and 9). So that you will be asked to match a series of things, but they will be asked randomly so that for instance in Question 1, you will asked about the letters A-E in random order.