Name ____________________________________
Date___________________
Per_____
Unit 2 : Ecology Exam Review
Major Topics Covered:
Biotic vs Abiotic Factors
Levels of Ecology (population vs. community vs. ecosystem)
Symbiotic relationships (mutualism, parasitism, commensalism, herbivory, predation)
Trophic Structure
Succession and Disturbances
Biogeochemical Cycles- Nitrogen, Carbon, Water and Phosphorus
From Last Test
Population ecology
Organisms Distribution
Logistic vs. Exponential graphs and carrying capacity
Density dependent vs. density independent limiting factors
Conservation and Restoration Biology
Biodiversity Crisis
Three levels of biodiversity
Invasive species packet – Literature review and matching with each animal
One question from each quiz from the biodiversity crisis student presentations
1.
BIOTIC
ABIOTIC
Definition
Example
2.
Population
Community
Ecosystem
Definition
Abiotic ____ Biotic ____
Example
Abiotic ____ Biotic ____
Abiotic ____ Biotic ____
3. Organisms that fill the same ______________ in an ecosystem, will be in _____________ with each
other
4. __________ is the abiotic reservoir of nitrogen
5. ______________ is unique because its cycle does not include the atmosphere
6. Carbon is in the form of ___________ in the atmosphere and enters the food chain after
_________________ has taken place.
7. Organisms only pass on _____ of usable energy or biomass up a trophic pyramid; 90% of it is lost as
_________.
8. _________________ are organisms that only eat producers; they are also known as ______________
9. Secondary consumers are usually meat eaters, also known as _____________.
10. Bears can eat berries, acorns, and other animals –they are known as _______________________.
Symbiotic Relationships:
C= Commensalism
P= Parasitism
H= Herbivory
Pr= Predation
M= Mutualism
___1. A tick living on a dog
___2. The honeyglide bird leading the honey badger to the bee hive; both eat honey
___3. A tapeworm living in a dog’s intestines, absorbing the dog’s nutrition
___4. The hermit crab carrying the sea anemone on its back
___5. A deer eating grass
___6. Orchids growing in tall trees; the trees are not harmed but the orchid gets light
___7. Bacteria living in the cow stomach to help it break down grass cellulose
___8. Wolves hunting elks
___9. Head lice living on the human scalp, eating the dead skin flakes
___10. Mistletoe putting its roots inside a host tree and leaching the nutrients
Trophic Level
1. What level consumer would the mackerel be? _________________
2. What percent of the population number was lost between the phytoplankton and the
zooplankton? ________
3. On average, how much energy is conserved between the levels of a trophic pyramid _______
Population Ecology
Models derived by ecologists describe two kinds of population growth. Exponential growth is
described by the equation G=rN. The number of individuals added to the population per unit of
time, G, depends on N, the size of the population, multiplied by r, the populations rate of increase.
Rate of increase, r, is calculated by subtracting the death rate from the birth rate. Exponential
growth is unregulated. The bigger the population, the faster it grows. This cannot be sustained for
long in real populations but it is a theoretical possibility. Population of fast reproducers such as
bacteria and insects can grow at-near exponential rates for short periods.
Let’s caluate and graph the exponential growth of a population of aphids for which r=40% (or 0.4)
per week. Remember that G=rN. If there are 10 aphids to start with, the number of aphids added by
the end of the first week (G) is equal to rN, or 0.4 x 10 =4. So, the population N after one week is
10+4=14.
1. Starting with a new total (N) of 14, how many aphids will be added (G) in the second week?
_____ Round DOWN decimals.
2. What will the total population be at the end of the second week?
3. Aphids added after the third week? _____ Total after the third week? ______
4. Aphids added in the fourth week? ______ Total? ______
5. Total at the end of the fifth week? ____ sixth week? _____ seventh week?_____
Eight week? _______ ninth week? _______ tenth week? _______
Graph the size of the aphid population (N) versus time (in weeks). Population size was 10 at time = 0.
Label the axes of the graph
6. How would you describe the shape of the graph? ___________________
7. Could this kind of growth continue indefinitely? Why or why not?
Real environments will not support exponential growth. Populations are limited by space, food supply,
or other factor that slow growth. The population may level off at a density the environment can
maintain- carrying capacity. The following data chart the growth of a population of deer on a small
protected island off the coast of British Columbia, recorded over a 50-year period.
1945
92
1975
814
1950
151
1980
765
1955
295
1985
688
1960
603
1990
740
1965
861
1995
729
1970
920
2000
738
1. Graph the growth of the deer population above. What is the overall shape of the graph?
______________
2. What happened to the population in the 1970s? ___________________
3. What may have caused this? ___________________
4. What is your estimate of the carrying capacity of the island for the deer?
5. What is the biological term for this kind of growth? ___________________
Population growth is limited by both density-dependent (biotic) and abiotic factors. Density
dependent and abiotic factors affect birth rates and death rates in different ways. State whether
each of the following words or phrases related more to density-dependent factors (DD) or to abiotic
(A) factors (“density-independent”)
_____1. Have more of an effect when the population is larger
_____2. Competition for food
_____3. Fire
_____4. Predation
_____11. Disease
_____12. Heat and Cold
_____13. Cause rapid population growth followed by unpredictable crashes
_____14. Cause populations to stabilize in size, presumably near carrying capacity
Conservation Biology: Global Climate Change
1. Greenhouse gases such as _______, methane, and nitrous oxide are changing the climate
2. For millennia, the amount of CO2 in the air did not exceed 300 ppm, now it is ______ppm and
rising
3. Scientists have concluded that the increase in greenhouse gases is due to _______________
activities.
4. Plants use CO2 in the process of _______________, storing carbon as organic molecules
5. _________________ releases the CO2 back into the atmosphere
Using textbook (Chapter 38), define the following terms:
Restoration Ecology ______________________________________________________________
______________________________________________________________________________
Bioremediation _______________________________________________________________
______________________________________________________________________________
Sustainable Biosphere Initiative ___________________________________________________
______________________________________________________________________________
Sustainable Development ________________________________________________________
______________________________________________________________________________
Landscape Ecology ______________________________________________________________