Unit 9: Ecology Practice Test				Name:__________________________________

Multiple Choice
Identify the choice that best completes the statement or answers the question.

____	1)	A population is correctly defined as having which of the following characteristics?
I.     inhabiting the same general area
II.    belonging to the same species
III.  possessing a constant and uniform density and dispersion
A)	I only	B)	III only	C)	I & II only	D)	II & III only	E)	I, II, & III	

____	2)	Uniform spacing patterns in plants such as the creosote bush are most often associated with
A)	chance.	
B)	patterns of high humidity.	
C)	the random distribution of seeds.	
D)	competitive interaction between individuals of the same population.	
E)	the concentration of nutrients within the population's range.	

____	3)	Which of the following assumptions have to be made regarding the capture–recapture estimate of population size?
I.     Marked and unmarked individuals have the same probability of being trapped.
II.    The marked individuals have thoroughly mixed with the population after being marked.
III.   No individuals have entered or left the population by immigration or emigration, and no individuals have been added by birth or eliminated by death during the course of the estimate.
A)	I only	B)	II only	C)	I & II only	D)	II & III only	E)	I, II, & III	

____	4)	Which of the following is the best example of uniform distribution?
A)	bees collecting pollen in a wildflower meadow	
B)	snails in an intertidal zone at low tide	
C)	territorial songbirds in a mature forest during mating season	
D)	mushrooms growing on the floor of an old growth forest	
E)	a cultivated cornfield in the Midwest	

____	5)	Consider two forests: one is an undisturbed old –growth forest, while the other has recently been logged. In which forest are species likely to experience exponential growth, and why?
A)	Old growth, because of stable conditions that would favor exponential growth of all species in the forest.	
B)	Old growth, because each of the species is well established and can produce many offspring.	
C)	Logged, because the disturbed forest affords more resources for increased specific populations to grow.	
D)	Logged, because the various populations are stimulated to a higher reproductive potential.	
E)	Exponential growth is equally probable in old –growth and logged forests.	

____	6)	As N approaches K for a certain population, which of the following is predicted by the logistic equation?
A)	The growth rate will not change.	
B)	The growth rate will approach zero.	
C)	The population will experience a crash.	
D)	The population will increase exponentially.	
E)	The carrying capacity of the environment will increase.	

____	7)	Carrying capacity is
A)	seldom reached by marine producers and consumers because of the vast resources of the ocean.	
B)	the maximum population size that a particular environment can support.	
C)	fixed for most species over most of their range most of the time.	
D)	determined by density and dispersion data.	
E)	the term used to describe the stress a population undergoes due to limited resources.	

____	8)	Which of the following statements about the evolution of life histories is correct?
A)	Stable environments with limited resources favor r–selected populations.	
B)	K–selected populations are most often found in environments where density–independent factors are important regulators of population size.	
C)	Most populations have both r– and K–selected characteristics that vary under different environmental conditions.	
D)	The reproductive efforts of r–selected populations are directed at producing just a few offspring with good competitive abilities.	
E)	K–selected populations rarely approach carrying capacity.	

____	9)	Which of the following pairs of reproductive strategies is consistent with energetic trade–off and reproductive success?
A)	Pioneer species of plants produce many very small, highly airborne seeds, whereas large elephants that are very good parents produce many offspring.	
B)	Female rabbits that suffer high predation rates may produce several litters per breeding season, and coconuts produce few fruits, but most survive when they encounter proper growing conditions.	
C)	Species that have to broadcast to distant habitats tend to produce seeds with heavy protective seed coats, and animals that are caring parents produce fewer offspring with lower infant mortality.	
D)	Free–living insects lay thousands of eggs and provide no parental care, whereas flowers take good care of their seeds until they are ready to germinate.	
E)	Some mammals will not reproduce when environmental resources are low so they can survive until conditions get better, and plants that produce many small seeds are likely found in stable environments.	

____	10)	Pacific salmon and annual plants are excellent examples of
A)	cohort disintegration.	D)	iteroparous reproduction.	
B)	dispersion.	E)	semelparous reproduction.	
C)	Allee effect.	

____	11)	In which of the following situations would you expect to find the largest number of  K–selected individuals?
A)	a recently abandoned agricultural field in Ohio	
B)	the sand dune communities of south Lake Michigan	
C)	the flora and fauna of a coral reef in the Caribbean	
D)	South Florida after a hurricane	
E)	a newly emergent volcanic island	

____	12)	Why do populations grow more slowly as they approach their carrying capacity?
A)	Density–dependent factors lead to fewer births and increased mortality.	
B)	Density–independent factors lead to fewer births and increased mortality.	
C)	Hormonal changes promote higher death rates in crowded populations.	
D)	Individuals voluntarily stop mating so that overcrowding does not occur.	
E)	The incoming energy decreases in populations experiencing a high rate of increase.	

____	13)	Which of the following could be a density–independent factor limiting human population growth?
A)	pollution	C)	plagues	E)	social pressure for birth control	
B)	earthquakes	D)	famines	

Use the survivorship curves in Figure 53.1 to answer the following questions.

____	14)	Which curve best describes survivorship in marine molluscs?
A)	A	B)	B	C)	C	D)	D	E)	E	

____	15)	Which curve best describes survivorship in a marine crustacean that molts?
A)	A	B)	B	C)	C	D)	D	E)	E	

____	16)	Which of the following graphs illustrates the growth curve of a small population of rodents that has grown to reach a static carrying capacity?

A)				
B)				
C)		

D)		
E)		

____	17)	Which of the above graphs illustrates the growth over several seasons of a population of snowshoe hares that were introduced to an appropriate habitat also inhabited by predators in northern Canada?

The following questions refer to Figure 53.3, which depicts the age structure of three populations.

____	18)	Assuming these age–structure diagrams describe human populations, in which population is unemployment likely to be a societal issue in the future?
A)	I	
B)	II	
C)	III	
D)	No differences in the magnitude of future unemployment would be expected among these populations.	
E)	It is not possible to infer anything about future social conditions from age–structure diagrams.	

____	19)	To measure the population of lake trout in a 250–hectare lake, 400 individual trout were netted and marked with a fin clip, then returned to the lake. The next week, the lake was netted again, and out of the 200 lake trout that were caught, 50 had fin clips. Using the capture–recapture estimate, the lake trout population size could be closest to which of the following?
A)	160	B)	200	C)	400	D)	1,600	E)	80,000	

____	20)	Which pair of terms most accurately describes life history traits for a stable population of wolves?
A)	semelparous; r–selected	D)	iteroparous; K–selected	
B)	semelparous; K–selected	E)	iteroparous; N–selected	
C)	iteroparous; r–selected	

____	21)	Which of these ecosystems accounts for the largest amount of Earth's net primary productivity?
A)	tundra	C)	salt marsh	E)	tropical rain forest	
B)	savanna	D)	open ocean	

____	22)	The total biomass of photosynthetic autotrophs present in an ecosystem is known as
A)	gross primary productivity.	D)	secondary productivity.	
B)	standing crop.	E)	trophic efficiency.	
C)	net primary productivity.	

____	23)	How is net ecosystem production (NEP) typically estimated in ecosystems?
A)	the ratio of producers to consumers	
B)	the amount of heat energy released by the ecosystem	
C)	the net flux of CO2 or O2 in or out of an ecosystem	
D)	the rate of decomposition by detrivores	
E)	the annual total of incoming solar radiation per unit of area	

____	24)	What is the primary limiting factor for aquatic productivity?
A)	pressure	C)	light availability	E)	competition	
B)	lack of nutrients	D)	herbivores	

____	25)	A 3–hectare lake in the American Midwest suddenly has succumbed to an algal bloom. What is the likely cause of eutrophication in freshwater ecosystems, such as this one?
A)	increased solar radiation	
B)	introduction of non–native tertiary consumer fish	
C)	nutrient runoff	
D)	accidental introduction of a prolific culture of algae	
E)	iron dust blowing into the lake	

Numeric Response

There are 780 turkeys living in a 92 acre plot of land.  The birth rate is 0.472 turkeys/year per capita.  The death rate is 0.331 turkeys/year per capita.

	1)	What is the population density?  Round to the nearest tenth.

	2)	What is dN/dt?  Round to the nearest whole number.

	3)	Predict N after one year, assuming dN/dt stays constant.  Round to the nearest whole number.

	4)	One dandelion can produce many seeds, leading to an exponential growth rate in the right environment.  If a population of dandelions is 40 individuals with an rmax = 0.2 dandelions/month per capita, predict how many individuals would be in this population after 2 months.  Round to the nearest whole number.

	5)	Imagine the dandelion population from the previous question cannot continue to grow exponentially due to lack of space.  The carrying capacity for their patch of lawn is 70 individuals.  What is their dN/dt in this logistic growth situation?  Round to the nearest tenth.

Unit 9: Ecology Summative Questions
Answer Section

MULTIPLE CHOICE

	1)	ANS:	C	TOP:	Concept 53.1		

	2)	ANS:	D	TOP:	Concept 53.1		

	3)	ANS:	E	TOP:	Concept 53.1		

	4)	ANS:	C	TOP:	Concept 53.1		

	5)	ANS:	C	TOP:	Concept 53.2		

	6)	ANS:	B	TOP:	Concept 53.3		

	7)	ANS:	B	TOP:	Concept 53.3		

	8)	ANS:	C	TOP:	Concept 53.4		

	9)	ANS:	B	TOP:	Concept 53.4		

	10)	ANS:	E	TOP:	Concept 53.4		

	11)	ANS:	C	TOP:	Concept 53.5		

	12)	ANS:	A	TOP:	Concept 53.5		

	13)	ANS:	B	TOP:	Concept 53.6		

	14)	ANS:	E	TOP:	Concept 53.1		

	15)	ANS:	D	TOP:	Concept 53.1		

	16)	ANS:	E	TOP:	Concept 53.3		

	17)	ANS:	D	TOP:	Concept 53.5		

	18)	ANS:	A	TOP:	Concept 53.6		

	19)	ANS:	D	TOP:	Concept 53.1		

	20)	ANS:	D	TOP:	Concept 53.4

	21)	ANS:	D	TOP:	Concept 55.2		

	22)	ANS:	B	TOP:	Concept 55.2		

	23)	ANS:	C	TOP:	Concept 55.2		

	24)	ANS:	B	TOP:	Concept 55.2		

	25)	ANS:	C	TOP:	Concept 55.2		

NUMERIC RESPONSE

	1)	ANS:	8.5

	2)	ANS:	110

	3)	ANS:	890

	4)	ANS:	58

	5)	ANS:	3.4