Practice Quiz 20 (Population Ecology, Community Ecology)
You have 30 minutes to finish the quiz.
Q.1:
A population reaches the carrying capacity of the environment for that species when the
min. number of indiv. that can be supported by the environment is reached
population has reached the max. number of indiv. that can be supported by the environment
when the death rate exceeds greatly the birth rate
when the birth rate exceeds greatly the death rate
Q.2:
Under natural conditions populations
can not grow exponentially
grow only exponentially
can not grow exponentially for a long time
grow exponentially for long periods in old environments
all are correct
Q.3 :
Which of the following is not a density dependent population regulation
immigration
predations
rainfall
emmigration
Q.4 :
A survivorship curve shows a linear relatioship between age ( x-axis) and % survial (y-axis ). This is typical for species such as
cod
salmon
birds
human
Q.5 :
The life cycle of some organisms includes different morphological forms, allowing them to exploit different resources in an ecosystem. Which of the following species exhibits such a behavior.
sea star
Cnidarians ( Jellyfish)
snakes
All of the above.
none of the above
Q.6.
If the larvae (juvenile offspring) of a particular species of mosquito are to survive to the adult stage, the eggs must be laid in the trapped pool of water of the northern pitcher plant. The mosquito larvae provide no apparent benefit or harm to thepitcher plant. This type of interaction is an example of _____.
parasitism
competition
predation
mutualism
commensalism
Q.7 :
In a life table the number of individuals alive beginning of the 1-year to the 2-year age interval is 800. During this interval 200 individuals die. The survival rate for this interval is
600
0.25
0.75
0.6
none of the above
Q.8:
The age structure of a population has a pyramidal shape. (# of individuals, male and female versus age ). Such a shape is charateristic for a population
such as present day US
with a high birth rate and low life expectancy
low birth rate and high life expectancy
such as in present day France
Q.9 :
Keystone species are those species
who are genetically most diverse
with the largest number of individuals in an ecosystem
who are best adapted to their environment
whose absence would cause major disruption in an ecosystem
all of the above
Q.10 :
The reproductive value of a species
a) is related to an organisms ability to have offspring with a high probability of survival
b) is low in immature individuals
c) is zero for individuals in their post reproductive age
a and c
all of the above
Q.11 :
In an S-shaped growth pattern, the growth rate of a population increases up to a certain population density. As the population increases further the growth rate declines. Such a growth curve is NOT observed
in presence of predators
if there is competition for food
if there is competition for space
if the population was subjected to a catastrophic event
all the above would produce an S-shaped growth curve
Q.12 :
The functional response of a predator (prey abundance vs predation rate)
is linear for filter feeders such as the basking shark
is hyperbolic if the feeding rate increase more slowly than the prey abundance
is sigmoidal in case of prey switching at low prey density
all are correct
Q.13:
Identify the mismatched pair
r-strategists - long lived with few offspring
freshly exposed glacier morraine - trees
K-strategists - rapid colonizers
all are mismatched
Q.14:
A predator-prey relationship can be identified from the a plot of the concentration of the organisms vs. time by:
Prey concentration is always greater than predator concentration
Equal concentrations of predators and prey
Constant predator concentration
Predator population proportional to the prey concentration
Oscillatory nature of the concentrations of both predator and prey
Q.15
Balanus baloides and Chthamalus stallus settle in the intertidal zone of rocky shores. Which statement is false?
removal of Balanus baloides has a niche expansion effect on Chthamalus stallus
the ecological niches of the two species are not the same
Larval Chthamalus stallus settle in the Balanus baloides zone
competition for food in the tidal range is the major reason for segregation of the two species
all statements are correct
Q.16 :
The sea star, abundant in the rocky intertidal zone feeds promarily on the mussel M. californianus.
M. californianus goes extinct in presence of the sea star
the variety of other intertidal species is greater when the sea star is present
the variety of other intertidal species is less when the sea star is present
the variety of other intertidal species is not affected by the sea star
Q.17 :
Which of the following is NOT an example of resources?
food
water
nesting space
chemicals, such as salinity
all of the above are examples of resources
Q.18 :
The following shows the yearly mortality rate of one of the finch species on Floreana: ( reported for 8 consecutive years) : 0.55, 0.14, 0.14, 0.07, 0.04, 0.31, 0.45. 0.09, The mortality rate is best explained by:
higher birth rates
influence of environmental factors
immigration
emmigration
all of the above
Q.19:
The above diagram shows ______ . The carrying capacity of the population is reached at _____
exponential growth , e
exponential growth d
logistic growth , c
logistic growth e
logistic growth d
Q.20 :
Amensalism decribes a relationship which is
mutually beneficial
benefical for one species and harmful for the other species
neutral to one species and harmful to the other
neutral to both species
neutral to one species and beneficial to the other