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Ecology Exam 4
Terms in this set (83)
Components of soil include
a. Chemically modified minerals
b. unaltered minerals
c. organic matter
f. living organism
For a consumer, which of these factors figure into food quality? Obviously, these will vary between herbivores and carnivores, but choose any and all that could apply to either.
a. Energy content
d. Cost of capture
all of these
Major adaptations of carnivores for nutrient acquisition include which of these?
All but d
a. Modifications for prey detection
b. Modifications for capturing prey
c. Modifications for killing prey
e. Increased visual acuity
f. Increased olfactory acuity
g. Heat detection
Marginal Value Theorem
All but C
a. Addresses optimal foraging with respect to the spatial distribution of food
b. Assumes that food items occur in patches where the food items vary in density
d. Measures responses by how long an animal stays in a particular patch. This is called giving up time
e. Giving up time is influenced by food density AND the distance between patches
Oyster catcher foraging behavior
a. Demonstrates the role of handling time and energy spent in consumption in predicting an animals diet
b. Is exemplified by failure to eat small mussels because, although they are not difficult to open, the food reward is too small
c. Is exemplified by failure to eat the largest mussels because, although they represent a large energy return, the time and energy required to open them is too great
d. Is exemplified by failure to specialize on the largest mussels because they are rare, meaning that search time would be too great.
Plants may acclimate to lowered light conditions by reducing respiration rate which will
T or F. Different plant species are adapted to different light intensities
T or F. One of the morphological responses of a plant to lowered PAR is to make smaller, thicker leaves, concentrating the mesophyll cells into a smaller area.
T or F. A plant adapted to low light levels can actually exhibit higher rates of photosynthesis in low light conditions than a plant that is adapted to bright light conditions
T or F. As a result of biological transfer efficiency, there are no quinary predators.
T or F. As an animal forages its total energy investment continues to steadily increase.
T or F. As carnivores occupy higher and higher trophic levels the ability to find mates becomes more difficult.
T or F. For any heterotroph, e.g. consumer, food availability and quality vary over space and time.
T or F. Natural selection acts on foraging behavior to maximize energy gain.
T or F. Predator populations are always smaller than their prey populations because of one of the laws of thermodynamics.
T or F. Soil characteristics are influenced by local topography
T or F. Soils determine the plants that grow in them. Plants determine characteristics of the soil.
T or F. The parent material ie bedrock has a major influence on soil characteristics
T or F. Optimal foraging theory holds that we can predict an organisms diet and foraging behavior because natural selection should adapt organisms to maximize energy efficiency.
The behavior that crows exhibit while foraging on clams demonstrates, what?
The efficiency of energy transfer between one trophic level to the next is about blank percent
The idea that in every energy transfer some of that energy is lost as heat is described by, what?
the second law of thermodynamics
Which of these are general characteristics of omnivores?
- they feed on multiple tropic levels
-they have modified digestive systems to digest course plant material
-They have morphological specializations for capturing prey
Which of these describe the model of optimal foraging theory
A, E, F, H
-a. P is equal to E over t, where P is profitability, E is net energy, and t is the time and energy invested in finding and obtaining the food
e. E is energy spent minus energy gained
f. t can be divided into search time and handling time
h. This is a conceptual model that allows us to make quantitative predictions about animal diet
Why are omnivores able to reach higher population densities than carnivores?
A and B
-One of the laws of thermodynamics
-by feeding occasionally on lower tropic levels there is more energy available for them in the environment
all life table parameters can be calculated from
How do we calculate generation time, Tg, from life table parameters?
. d. Tg is equal to the sum of xlxmx divided by R0
Identify the appropriate life table parameter. An intermediate calculation for life expectancy
Identify the appropriate life table parameter. For an individual alive at the beginning of age interval x, this is the average number of age intervals this individual is expected to live
Identify the appropriate life table parameter. The age class or interval
Identify the appropriate life table parameter. The average number alive during an age class
Identify the appropriate life table parameter. The number of organisms dying between the beginning of age interval x and the next age interval
Identify the appropriate life table parameter. The number of survivors at the beginning of age interval x
Identify the appropriate life table parameter. The proportion of organisms surviving to age interval x out of the total number born
Identify the appropriate life table parameter. The rate of mortality between the beginning of age interval x and the next age interval
If 400 individuals were alive in age class 1 and 300 individuals were alive in age class 2, what would be the value of Lx?
If R0 is
a. Greater than 1 the population is declining
b. Less than 1 the population is increasing
c. Equal to 1 the population is zero
none of these
In order to determine the age structure of a population more than one approach is possible. These different approaches include
A, B, and C
a. Follow members of a cohort from birth until death
b. Record the age of death for many individuals within a short period of time
c. Record the age structure of a population at a point in time
In order to understand how populations change over time, and in order to calculate all the parameter towards that end, we need two pieces of data. They are
B and E
T or F. Fx refers to the average number of offspring produced by an entire age class of females.
T or F. Once we have lx and mx for all the age classes in a population we can calculate the net reproductive rate of the population. It is with this parameter, R0, that we can now understand how the population changes over time.
The population parameter mx refers to
A and B
a. The average number of female offspring produced per female
b. Age specific fecundity
There are two general types of population model. They are
A and D
To calculate R0, we first multiply lx by mx for each age class. Then we
Simply sum these products
Which survivorship curve demonstrates very high mortality in the youngest age classes?
Which survivorship curve is typical of most birds, small mammals, and lizards?
Which survivorship curve is typical of most invertebrates?
Which survivorship curve is typical of most mammals, especially larger mammals?
Which survivorship curve shows a relatively constant mortality rate across age classes?
Can r be calculated from R0
e. Yes. r is equal to the natural log of R0 divided by generation time
Ecological models are designed to capture and explain only key features for
B, D and G
For a population limited by available resources, when is population growth the fastest?
At one half K
For populations with discrete generations, how do we use R0 to determine the size of the population after one time unit, e.g. to model geometric growth?
a. The population size at Nt plus 1 is equal to Nt times R0
If lambda is equal to 1.1 and the population size now is 100, how many individuals will be in the population after 7 time units?
If R0 is equal to 1.25 and the population size is 100, how many individuals will be in the population after one time unit?
If we integrate the model of geometric growth for continuous breeders we are able to calculate the doubling time of a population. Which of these is the equation that results from taking the integral.
b. Nt is equal to N0e raised to the power of rt
In population ecology K denotes blank and means blank in the model
c. Carrying capacity and the number of individuals that can be sustained by available resources
In the modified logistic equation which incorporates the effect of time lag, what is represented by tau?
The number of individuals produced during the time lag
T or F. Introduced species often exhibit dramatic geometric population growth.
T or F. Rinderpest is an introduced disease that was introduced to India from the African continent.
T or F. The reindeer that were introduced to Pribilof Island lived happily ever after.
The effect of time lag is that
Populations can increase beyond K
The population model for geometric growth for organisms with overlapping generations is
dN over dt is equal to rN
The time it takes for rate of population change to respond to crowding is called, what?
The time it takes for the rate of population change to respond to crowding is expressed as...HINT the answer is 1/r
1 over r
Which if these is the logistic growth equation?
b. dN over dt is equal to rN times, inclusive K minus N over K
Which of these are accurate descriptors of a model, as used in ecology?
all but C
a. They are deterministic
b. They are simplified abstractions of reality
d. Models begin as hypotheses about how a system works, considering only the most important factors
e. Accurate models are important scientific tools
Which of these are assumptions of the logistic growth equation?
a. For every new individual added the population growth rate decreases by the same amount
b. The effect of density on rate of increase is instantaneous
c. The environment, therefore K, is constant
d. All individuals reproduce equally
e. There is no immigration or emigration
(all of these)
Which of these species exhibited dramatic geometric population growth?
(all of these)
a. Lamprey in the Great Lakes
b. Rabbits in Australia
c. Brown tree snakes in Guam
d. Reindeer on Pribilof Island of Alaska
e. Alligators in the southeastern United States
f. Whooping Cranes in the United States
Who was responsible for incorporating time lags into the logistic growth equation?
Why are models important in ecology?
Ecological systems are complex
Early experiments with microbes and yeast cells in flasks of measured nutrients and energy sources supported the logistic growth model quite well. In terms of the assumptions of this model, why do you think that was the case? Choose all that apply
How quickly the rate of population change responds to overcrowding is called
If the product of r and tau is greater than 1.57 then
The population will exhibit stable limit cycles and the population will fluctuate regularly above and below K indefinitely
If the product of r and tau is less than 0.368 then
d. The population will increase smoothly to K and stay there
If the product of tau and r is between 0.368 and 1.57 then
The population will exhibit dampened oscillations
Stochastic models differ from deterministic models that in that they tell us
a. A range of possible population sizes in the next generation
b. The probabilities of various possible population sizes in the next generation
c. A range of possible population projections over several time periods
d. The probabilities of possible population projections over several time periods
(all of these)
T or F. In populations with discrete generations and an r times tau product of 1 time unit, r controls population behavior.
T or F. Stochastic population models are more realistic and necessarily more useful.
T or F. The probability of a population going extinct decreases exponentially as the number of individuals in the population increases
The formula for calculating how quickly the rate of population change responds to overcrowding is
1 over r
The usefulness of population models depends more on blank than their current structure and assumptions
We can predict the behavior of populations from
Tau times r
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