Biology 307

Exam Two

In multiple choice questions, choose the one best answer unless instructed otherwise.

(15) 1.Graphing Section. One the back of this page, draw the graphs (A-E). All axes must be properly labeled and identified (A, B, C etc.).

A) Type 3 (high juvenile mortality) survivorship curve.

B) Typical mortality curve for male mammals such as the impala, showing the effects of male-male competition.

C) Nonlinear effect of population density on birth rate (as a result of intraspecific competition).

D) Human age structure diagram for a population undergoing extremely rapid population growth.

E) Typical fertility (m_x) versus age diagram for a population with a pre reproductive period of 2 years, a reproductive period of 3 years, and a post reproductive period of 2 years.

(18) 2.A fox population has the life table shown below. Find the Gross Reproductive Rate (GRR), and the Net Reproductive Rate (R₀). Would the intrinsic rate of increase (r) for this population be predicted to be positive, negative or zero?Why?Fill in the p_x, and q_x columns and, based on the n_x column for time = 0, project the population for one year (t =1).

Age	lx	mx	px	qx	nx at t = 0	nx at t = 1
0	1.00	0		40
1	0.30	0		10
2	0.25	2		8
3	0.20	3		6
4	0.10	2		2
5	0	0		0

(3) 3.Generation time:

A) is positively correlated with the intrinsic rate of increase (r).

B) is positively correlated with the size of an organism.

C) is positively correlated with the net reproductive rate (R₀).

D) is positively correlated with the finite rate of increase (?).

(3) 4.The work of Cole and other population ecologists has shown that the intrinsic rate of increase is most highly affected by:

A) whether an organism is semelparous or iteroparous.

B) the length of the pre reproductive period.

C) the age at which reproduction ceases.

D) the total life span of the organism.

(6) 5.According to the MacArthur and Wilson theory of r- and K-selection, which of the following are K-selected traits:

Excellent dispersal ability A few, large offspring

Highly developed competitive ability Type 3 survivorship curve

Found in late stages of succession  Rapid development rate

(4) 6.Define competition.

(4) 7. State the competitive exclusion principle of G. Hardin.

(4) 8.Why does it benefit a dunnock female to mate with more than one male?

(3) 9.In the Lotka-Volterra competition equations, the implied value of ?_1,1 (an intraspecific competition coefficient) is:

A)  0 

B)  1.0 

C)  -1.0 

D)  between 0 and 1

(3) 10.In the Lotka-Volterra competition equations, the value of the interspecific competition coefficient, ?_i,j is thought to be:

A) 0 

B) 1.0

C)  -1.0 

D) between 0 and 1

(3) 11.Which one of the following is a stochastic result of competition:

A) The two species coexist

B) Species one always out competes species two.

C) When two species compete, competitive exclusion always occurs, but species one wins 75% of the time (species two wins 25% of the time).

D) Species two always out competes species one.

(8) 12.After a series of experiments with two species of algae, half saturation constants, intrinsic rates of increase and death rates were established for each species for each of three nutrients. The R^* values for each species and for each nutrient is displayed below.

Species	R*nutrient 1	R*nutrient 2	R*nutrient 3
One	5.0	7.0	7.0
Two	10.0	3.5	5.0
Three	15.0	10.0	15.0

A) If only nutrient 1 is limiting (nutrients 2 and 3 are provided in excess of demand), and all three species are found in the same environment, what is the expected result?

B) Under the same conditions as in A) except that only species two and three are present, what is the expected result?

C) If nutrients 2 and 3 are both limiting (nutrient one provided in excess of demand), and all three species are placed in the same environment, what is the expected result?

D) Now consider an environment in which both nutrients 1 and 2 are limiting but only species one and two are placed in this environment. What is the expected result?

(4) 13.In the study by Connell, the barnacle Chthamalus was normally found in the upper regions of the intertidal zone, between high mean neap tide and high mean spring tide. Balanus, on the other hand, was usually found between mean tide level and high mean neap tide. What was the fundamental niche of Chthamalus? What was its realized niche?

(6) 14.Define contiguous allopatry.Give an example from the field.

(7) 15.In the example below, four lizard species consume insects of various sizes. The mean and standard deviations of insects consumed are displayed.

Lizard Species	Mean " standard deviation of insects consumed
One	5.7 " 1.3
Two	13.7 " 2.2
Three	15.0 " 4.4
Four	25.5 " 4.0

According to the concept of niche partitioning and the principle of limiting similarity, which pair of species should be unable to coexist? Would all four species be able to coexist if we were able to show that species one and two specialize on ants, while species three and four primarily consume beetles?Why?

(6) 16.Define character displacement and give an example.

(3) 17.In human disturbed habitats the red fox has begun to replace the arctic fox in regions of Alaska where only arctic foxes had been known to occur. This is an example of:

a) character displacement

b) niche partitioning

c) ecological release or historical replacement (depending on how one views the human disturbance)

d) all of the above.