Download Chapter 2: - Darlak4Science

Biology Standard 4B & 5B
“When one tugs at a single thing in nature,
they find it attached to the rest of the world.”
Ms. Darlak, C2
Scappoose HS
Name ______________________
Period: __________
Text
Biology, The Dynamics of Life. 2002.
Chapter 2.2 (pp. 48-54) Chapter 3.1 (p. 68) Chapter 5.1 (pp. 114-124)
Unit 2 Ecological Issues
Standard 4B Populations & Limiting Factors
Essential Questions:
How do organisms interact with their environment?
How do organisms influence other organisms in their same habitat?
HS-LS2-1
HS-LS2-2
 Use mathematical and/or computational representations to support explanations of factors that affect carrying capacity of ecosystems at
different scales.
 Use mathematical representations to support and revise explanations based on evidence about factors affecting biodiversity and
populations in ecosystems of different scales.
Learning Targets
I understand the concept of
carrying capacity and how
limiting factors influence
this, and use quantitative
analysis to determine the
carrying capacity
Beginning Proficient-1
I can identify limiting factors
and can tell the specific
factors that limit a given
habitat, quantitatively I
cannot tell the carrying
capacity without errors.
I can explain the concepts
of biodiversity and
population dynamics using
data, graphs, and figures.
I can identify what
biodiversity is and explain
population dynamics, but
cannot use data, graphs and
figures.
Learning Targets
I understand the concept of carrying
capacity and how limiting factors
influence this, and use quantitative
analysis to determine the carrying
capacity
I can explain the concepts of
biodiversity and population dynamics
using data, graphs, and figures.
Carrying capacity
Biodiversity
Overshoot
Succession
Developing Proficient-2
I can identify limiting
factors and can tell the
specific factors that limit a
given habitat,
quantitatively I can tell the
carrying capacity with
errors.
I can identify what
biodiversity is and explain
population dynamics, and
use data, graphs and
figures with errors.
Proficient-3
Given a scenario, I can
identify the limiting factors
that set the carrying
capacity of a given area and
can quantitatively
determine the carrying
capacity with little errors.
Given data, I can compare
different habitats on the
basis of biodiversity and
population dynamics with
little errors.
Highly Proficient-4
Given a scenario, I can
identify the limiting factors
that set the carrying
capacity of a given area
and can quantitatively
determine the carrying
capacity with no errors.
Given data, I can compare
different habitats on the
basis of biodiversity and
population dynamics with
no errors.
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Standard 4B Populations & Limiting Factors
I can define and identify a parasitism, commensalism, mutualism, predation and competition.
I can identify and define the difference between interspecific and intraspecific competition.
I can explain how limiting factors create a carrying capacity
I can identify if a limiting factor is density-dependent or density independent.
I can differentiate between an S curve (logistical) and an J curve (exponential)
I can use data to determine the carrying capacity for a given area and draw a dotted line to indicate it.
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I can find an average number of individuals in a given population
I can identify trends in population data over time
I can explain the concept of biodiversity using graphs and figures.
I can compare two habitats and explain which has more biodiversity based on given data, graphs and figures.
J curve
Average
Species Richness
Species Diversity
Vocabulary
S curve
Limiting factor
Threatened species
2
Logistical
Density dependent
Endangered species
Score
Standard 5B Outline
I.
Symbiotic Relationships
a. Parasitismb. Commensalismc. Mutualismd. Predatione. Competitioni. Intraspecifcii. Interspecific-
II.
Limiting Factorsa. Density Independenti. Examples:
b. Density Dependenti. Examples:
III.
Carrying Capacitya. Growth Curves
i. Logistic-
ii. Exponential-
IV.
Population Dynamics
a. Population Densityb. Dispersion Patterni. Uniformii. Clumpediii. Randomc. Age Structure-
V. Biodiversity
a. Species Diversity
b. Species Richness
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I. Symbiotic Relationships Notes (pp.46-47) or how species interact
o What kinds of behaviors do some species do to enhance their chances of survival?
o Some behaviors are harmful, some are beneficial.
Type of interaction
Species 1
Species 2
1. Commensalism
2. Mutualism
3. Parasitism
4. Predation (predator/prey)
5. Competition
Which Symbiosis is it?
1. Oxpecker and zebras: Oxpeckers are a type of small bird that land on zebras and eat ticks and
other parasites that live on the zebra’s skin. The oxpeckers get food and the zebras get pest
control.
Organism 1:  helped harmed not harmed/not helped
Organism 2:  helped harmed not harmed/not helped
Symbiotic Relationship: _____________________________
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2. Tapeworm and animals: Tapeworms are segmented flatworms that attach themselves to the
insides of the intestines of animals such as cows, pigs, and humans. Tapeworms get food by
eating the host's (animal) partly digested food, depriving the host (animal) of nutrients.
Organism 1:  helped harmed not harmed/not helped
Organism 2:  helped harmed not harmed/not helped
Symbiotic Relationship: _____________________________
3. Spider crab and algae: Spider crabs live in shallow areas of the ocean floor, and greenish-brown
algae lives on the crabs' backs, making the crabs blend in with their environment, and
unnoticeable to predators. The algae get a good place to live, and the crab gets camouflage.
Organism 1:  helped harmed not harmed/not helped
Organism 2:  helped harmed not harmed/not helped
Symbiotic Relationship: _____________________________
4. Remora and the shark: Remora fish are small fish that make their niche by picking up the scraps
that sharks leave behind while feeding. The shark makes no attempt to prey on the remora fish.
Organism 1:  helped harmed not harmed/not helped
Organism 2:  helped harmed not harmed/not helped
Symbiotic Relationship: _____________________________
5. Bee and the flower: Bees fly from flower to flower-gathering nectar, which they make into food.
When they land in a flower, the bees get some pollen on their hairy bodies, and when they land in
the next flower, some of the pollen from the first one rubs off, pollinating the plant.
Organism 1:  helped harmed not harmed/not helped
Organism 2:  helped harmed not harmed/not helped
Symbiotic Relationship: _____________________________
6. Bacteria and the human colon: Bacteria live in the colon of humans and are able to feed off the
indigestible food that the human body cannot break down (cellulose of plants). In the process of
breaking down the food, the bacteria also make much-needed vitamins that the human body in
turn can use to keep healthy.
Organism 1:  helped harmed not harmed/not helped
Organism 2:  helped harmed not harmed/not helped
Symbiotic Relationship: _____________________________
7. Dog and the tick: Ticks live on dogs and feed off the dog’s blood. They may also infect the dog
with a parasite that can cause the dog to become quite sick. Dogs also are sometimes found to
be very tired because a large volume of their blood has been drained.
Organism 1:  helped harmed not harmed/not helped
Organism 2:  helped harmed not harmed/not helped
Symbiotic Relationship: _____________________________
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II. Limiting Factors and Population Growth
A. Read the truly riveting passage below about population growth. If, while reading, you are asked to
do something, then do it.
B. Mark the following as you read:
DGT = I don’t get this. I had to re-read this to try and understand it.
!! = I am surprised to find this out
?? = I have a question about this (write your question in the margin)
C. Discuss what you marked and any changes you made after your table is done reading the passage
below. Have your table help you answer your questions and clarify what you don’t get.
The Ups and Downs of Population Growth
A population is a group of organisms of the same species that live in a certain area. Ecologists regularly
monitor the number of organisms in many populations, but why do they do this? Why do we care if the number
of organisms in an area is growing or shrinking? Well, populations that are growing and shrinking can be
indicators of potential problems occurring in the organisms’ environment, and gives ecologists a “heads up” if
something is going wrong. But it is not enough to simply know if the number of organisms in an area is going up or
going down; ecologists need to know why the number of organisms is fluctuating. So, one of the main questions
ecologists ask themselves is this: Why is a population’s size is going up or going down?
There are many factors that can cause a population’s size to change. But first, you must understand the
basic reasons behind why a population grows or shrinks. Any population, whether it be humans, chipmunks, the
mold growing on bread, or the bacteria living in your intestines, will grow if more organisms are being created, or
born, than are dying. If a population has more organisms dying than are being born, then the population will
shrink. The number of births in a population is called the birth rate (also referred to as natality). The number of
organisms that are dying in a population is called the death rate (also referred to as mortality). Thus, if the birth
rate is greater than the death rate, a population will grow. If the death rate is greater than the birth rate, then the
population will decrease in size.
Stop and Think #1:
a) The human population is currently growing at an exponential rate. What does this mean about our
birth and death rates?
b) The Mantled Howler Monkey (found in Mexico and South America) is currently considered an
endangered species. What does this mean about its birth and death rates?
While populations would probably like to continue to grow in size, a population of organisms cannot grow
forever—its growth will be limited, or stopped, at some point, and the death rate will be greater than the birth
rate. A population’s growth is limited by two general factors: density-independent factors and densitydependent factors. Why are these factors named in such a complicated way? Well, actually, these names aren’t
as complicated as they seem; in fact, they can even help you remember what each of the terms means.
To understand why scientists named these factors in the way they did, you must first understand the
concept of population density. A population’s density is NOT whether or not the population will float or sink (they
would probably sink. . .resulting in a lot of tragic, needless organism deaths). Population density refers to how
many organisms there are in one particular spot. If a population’s density is very high, that means there are a lot
of organisms crowded into a certain area. If a population’s density is low, that means there are very few
organisms in an area.
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Now that you know about population density, we can talk about the difference between the two types of
limiting factors. If a factor that stops a population’s growth is influenced by the population’s density, then it is
called a density-dependent limiting factor. If the population’s density does not influence whether or not the
factor stops the population’s growth, then it is called a density-independent limiting factor.
Stop and Think #2: Imagine a population of skunks. Yes, skunks. Imagine that the skunks are
reproducing at a very high rate, and the skunk population is growing rapidly—especially in the field
behind Ms. Darlak’s house.
a) List a possible density-independent factor that could stop the skunk population’s growth.
b) List a possible density-dependent factor that would limit the skunk population’s growth.
Revise your answers as you read more about density-independent limiting factors and densitydependent limiting factors
Density-independent limiting factors that can stop a population from growing can be such things as
natural disasters, temperature, sunlight, and the activities of humans in the environment. Natural disasters such
as tornadoes, floods, and fires will stop a population from growing no matter how many organisms are living in a
certain area. The same goes for the temperature of an area and the amount of sunlight an area receives—if the
temperature increases due to global warming, or if the ash kicked up into the atmosphere from an asteroid
smashing into the earth blocks out a lot of sunlight for a few decades, these will both cause a decrease in a
population’s numbers, no matter how large or small the population was to begin with. Human activities that alter
the environment will also decrease the amount of organisms in a population, no matter the size of the population.
Density-dependent limiting factors come into play when a population reaches a certain number of
organisms. Thus the number of organisms in the population matters when talking about density-dependent
limiting factors. For example, when a population reaches a certain size, there won’t be enough resources (food,
shelter, water) for all of the organisms. This could cause the population to stop growing when it reaches the
maximum number of organisms that can be supported, or “carried,” by the environment. This number is known
as the population’s carrying capacity. Each
population of organisms has a different carrying
capacity, depending on the area in which it lives and
the amount of resources available in that area.
Below is a graph of a rabbit population that has
reached its carrying capacity:
This type of population growth is called logistic
population growth; it represents what actually
occurs as a population’s numbers get too large for
the environment to support it. While the number of
rabbits in the population increased rapidly at first, its
growth began to slow down towards the end of
August. Once the population numbers leveled off,
roughly equal numbers of rabbits were dying as being born.
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Stop and Think #3: Study the graph on previous page showing the number of rabbits carefully.
a) What is the rabbit population’s carrying capacity? ________
b) The population of rabbits between mid-May and mid-June (shown with dots) is growing as fast as:
(circle one)
1. a turtle walking (super slow)
2. a student running late to class (fast!)
3. you walking to class (slow.)
4. Ms. Darlak running away from a mountain lion (super fast!)
c) What about the graph led you to circle the answer you chose in letter b?
Revise your answers (if necessary) as you read more about population growth.
Before a population reaches its carry
capacity, it experiences a period of rapid growth.
This period of growth is called exponential
population growth, because, mathematically, the
population is adding organisms at an exponential
rate. During this time period, there are plenty of
resources available for all organisms, so more
organisms are being born than are dying. The
graph for exponential population growth looks sort
of like the graph for logistic population growth,
only without the flat “leveling off” line at the end
of it:
Stop and Think #4:
a) Fill in the differences chart below:
density-independent limiting factor
density-dependent limiting factor
logistic population growth
exponential population growth
b) The human population is currently growing at an exponential rate. Since you have learned that
populations cannot grow forever, what are some things (more than one!) that could happen when
the human population reaches its carrying capacity?
Revise your answers as you read further, if necessary.
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The amount of resources is not the only limiting factor that depends on a population’s density. Diseases and
parasites can limit a population’s growth once the population reaches a certain number of organisms. The more
organisms there are, the faster a disease can spread or a parasite can be transferred to another organism because
there are more available hosts that are near each other. Competition for resources—either between the same
species or two different species—will also decrease a population’s size. Resources are limited in any habitat, and,
when populations reach a certain size, there will not be enough to go around. When two organisms in the same
habitat are trying to use the same resource, they are competing for that resource. Whichever organism has the
better adaptations to obtain that resource will be able to reproduce more often, and their population will grow.
The organism that is not successful at competing for the resource will not reproduce as often, and their population
will decrease.
Predation is another density-dependent limiting factor seen in populations. When lots of prey is available,
predators will eat the prey, have energy to reproduce, and their numbers will increase. The population of their
prey will begin to decrease as more and more of them are eaten. However, the predator population will
eventually reach carrying capacity—there will not be enough prey for all of the predators in the population, since
the predators themselves are competing for their “prey” resource. As the number of prey decreases, so will the
number of predators, because there isn’t enough food to go around. As the number of predators decreases,
which means the prey have time to reproduce and increase their population. Thus, predator-prey populations go
through cycles of population growth, which is shown in the graph below between lynx (predator) and snowshoe
hares (prey):
Stop and Think #5:
a) Pretend the graph on the previous page is the data you obtained after doing your own lab, and you are
filling out the lab write-up form. You get to the part of the form where you have to fill out your results
sentence. Using the data in the graph to guide you, fill out the results sentence below:
As the number of lynx increases, the number of snowshoe hares: ________________________.
b) Using what you know from the reading and from the graph, give a scientific explanation for the results
sentence you completed above.
A scientific explanation for these results is:
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One last density-dependent limiting factor that stops a population from growing is emigration.
Emigration occurs when, as a population approaches carrying capacity, individual organisms from the
population leave and go to a new area where they can find enough resources for survival and
reproduction. This, obviously, will cause a decrease in the amount of organisms in a population. You
may have heard of a word that has the exact opposite meaning and effect on population size—
immigration.
Stop & Think #6:
a) Knowing that immigration is the opposite of emigration, what does immigration mean?
b) Will immigration cause populations to increase or decrease in size? ___________________
c) Using Scappoose as an example, give an example of immigration and emigration’s effects on the population
of humans in Scappoose.
Read each situation in the chart below. Then, state if it is a density-independent limiting factor or a
density-dependent limiting factor. Then, state the specific limiting factor that is occurring. The first one
is done for you as an example.
Situation
Ms. Darlak has 32 students assigned to her Biology class, but she only
has room for 28. Because the room is so crowded, the extra 4
students leave the room to go to Counseling and have their schedules
changed.
Northern pike (it’s a fish) feed on another fish, the yellow perch. An
increase in the yellow perch population causes an increase in the
northern pike population.
The BP oil spill in the Gulf of Mexico has harmed many aquatic
organisms that live in the Gulf region.
A new strain of influenza (the flu) breaks out in New York City.
A population of rabbits and a population of deer are both feeding off
the same plants in the same habitat.
Hurricane Katrina forced thousands of people to leave New Orleans.
65 million years ago, a large asteroid collided with the Earth. As a
result, large amounts of ash were ejected into Earth’s atmosphere.
Due to humans putting increasing amounts of greenhouse gases into
the atmosphere and cutting down trees that would normally take up
some of those gases, the Earth slowly gets warmer and changes
climates around the globe.
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Density-independent,
or density-dependent?
density-dependent
Limiting
Factor:
emigration
III. Carrying Capacity
Growth Curves
1. Complete the following table for the two types of growth curves:
growth curve
shows
unlimited,
unchecked
growth
growth limited
by extrinsic or
intrinsic
factors
shape of curve
(S or J)
shows carrying
capacity for a
population.
typical of
short term or
long term
growth
exponential
logistic
2. Directions: For each of the following scenarios circle whether the population growth would best be
represented by a logistic or exponential growth curve.
a. a strep bacterium invades your throat and reproduces for 4 hours
exponential logistic
b. the flea population on a rat is monitored for 5 weeks with flea powder added
exponential logistic
c. loggerhead turtle populations are tracked for 10 years in the Atlantic
exponential logistic
d. a lucky yeast cell falls into your glass of grape juice and reproduces for 3 hours
exponential logistic
e. bull frog population in a local pond is monitored for 5 seasons
exponential logistic
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Population Ecology Graph Worksheet
Directions: Look at the graphs below and answer
the following questions.
Graphs 1 - Exponential Growth and Carrying
Capacity
1. Which of the two curves exhibits exponential
growth? _______________________________
2. Which of the two curves exhibits a carrying
capacity? _______________________________
3. What is the carrying capacity of this graph?
_____________________________
4. In what generation does this population reach
its carrying capacity?
__________________________
Graph 2
1. For what type of organism is the carrying capacity
shown? _______________________________
2. Give one possible reason why the population decreased
in 1990 after it had reached its carrying capacity.
_________________________________________________
3. Give one hypothesis to explain why the population
exceeded its carrying capacity in 1992.
_________________________________________________
4. Why did the population decrease in 1994 after it
exceeded the carrying capacity? _____________________
_________________________________________________
Graph 3 - Competition Curve
Graph 4 shows the growth of 2 species
of bacteria grown on the same petri
dish. It also shows their growth rate
when grown separately.
1. Which of the 2 types of bacteria will
soon die? Why?
_______________________
2. Which of the 2 bacteria strains is
better adapted for competition?
__________________________________________________________________________________________
3. How is the growth rate for P. caudatum different when it is grown alone?
____________________________________________________________________________________________
4. What happens to the growth rate of P. aurelia around day 12?
____________________________________________________________________________________________
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Graph 4 – Predator-Prey Graph
Isle Royale National Park on a
remote island was established in
1940, and designated a
wilderness area in 1976. The only
mode of transportation available
is by boat or seaplane. Moose
first arrived at Isle Royale around
1900. The moose population
tends to increase in years with
mild winters, early spring greenup, abundant winter forage, low
wolf numbers and low levels of
tick infestation. Wolves first
arrived at the island on an ice
bridge from Canada in 1940.
Disease has also influenced the wolf population. Between 1980 and 1982, the wolf population declined from 50
to 14, due to canine parvovirus.
1. What is the greatest moose population? What year did that occur? What was the wolf population when
the moose population the greatest? ______________________________________________________
_________________________________________________________________________________
2. What would happen to the wolf population if the moose population decreases? __________________
___________________________________________________________________________________
3. What would happen to the moose population if the wolves were removed from Isle Royale?
___________________________________________________________________________________
4. Describe the pattern between the wolf (predator) population in relation to the moose (prey) population.
___________________________________________________________________________________
5. Identify a factor, other than moose population, that has influenced the wolf population in Isle Royale.
___________________________________________________________________________________
6. Identify two factors, other than the wolf population, that may influence the moose population.
___________________________________________________________________________________
___________________________________________________________________________________
7. Isle Royale has been undeclared as a national park and has been purchased by a large resort.
Describe one positive and one negative impact on the Isle Royale ecosystem. _____________________
___________________________________________________________________________________
___________________________________________________________________________________
8. Are predator-prey relationships density-dependent or density-independent limiting factors? Explain.
___________________________________________________________________________________
___________________________________________________________________________________
IV. Population Dynamics
Estimating Population Size
Objective: You will be expected to estimate the size of a sample population
using the mark-recapture technique. Be able to apply the technique to new
population problems and compare the mark and recapture technique to other
methods of population estimating.
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1. If you were in charge of a team given the responsibility to determine the number of
sunfish in Horseshoe Lake, discuss with your partner how would you accomplish this
task and describe in detail below.
A. Technique 1: Sampling
A technique called sampling is sometimes used to estimate population size. In this
procedure, the organisms in a few small areas are counted and projected to the entire
area. For instance, if a biologist counts 10 squirrels living in a 200 square foot area, she
could predict that there are 100 squirrels living in a 2000 square foot area.
2. A biologist collected 1 gallon of pond water and counted 50 paramecium. Based on
the sampling technique, how many paramecium could be found in the pond if the pond
were 1,000 gallons?
3. What are some problems with this technique? What could affect its accuracy?
DATA
B. Technique 2 - Mark and Recapture
In this procedure, biologists use traps to capture the
animals alive and mark them in some way. The
animals are returned unharmed to their
environment. Over a long time period, the animals
from the population are continued to be trapped and
data is taken on how many are captured with tags.
A mathematical formula is then used to estimate
population size.
Procedure:
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Trial Number Number
Captured
Number Recaptured
with mark
1
2
3
4
5
6
7
8
You will receive a bag that represents your
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population (beans, pennies, chips, beads)
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Capture 10 “animals” by removing them
randomly from the bag.
Total:
Place a mark on them using tape or string
Return the 10 marked “animals” to the container
With your eyes closed, grab a handful of the population. This is
the recapture step. Record the number of “animals” recaptured in total and the
number that have a mark on them on the data table
Return the “animals” to the bag and repeat. Do 10 recaptures.
When the ten recaptures are completed, enter the totals on the data table
4. Calculations = Find your Population Estimate
Estimated Size ___________
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5. Use the code-name on your bag to check with the teacher about how many “animals” are
really in your population.
Name on Bag ___________________________ Actual Size _________
Analysis
6. Compare the actual size to the estimated size. Did
you overestimate or underestimate?
Trial
Number
Number Captured
Number
Recaptured
with mark
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7. Continue the experiment by filling out the data
table.
Recalculate your estimate using the formula. (Show
below)
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13
14
15
a. Is the second estimate closer than the first one?
______
b. To get the most accurate results, you would
generally
do [ more / less ] trials . (circle)
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8. Given the following data, what would be the
estimated size of a butterfly population in Wilson
Park. A biologist originally marked 40 butterflies in
Wilson Park. Over a month long period butterfly traps
caught 200 butterflies. Of those 200, 80 were found to
have tags. Based on this information, what is the
estimated population size of the butterflies in Wilson
Park? SHOW WORK to get credit.
20
17
18
19
Add all
20 trials
together
Total:
Random Sampling
Scientists cannot possibly count every organism in a population. One way to estimate the size of
a population is to collect data by taking random samples. In this activity, you will look at how
data obtained from random sampling compare with data obtained by an actual count.
Procedure:
1. Tear a sheet of paper into 20 slips, each approximately 4cm x 4 cm.
2. Number 10 of the slips from 1 to 10 and put them in a small container.
3. Label the remaining 10 slips from A through J and put them in a second container.
The grid shown below represents a meadow measuring 10 m on each side. Each grid segment
is 1m x 1m. Each black circle represents one sunflower plant.
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5. Repeat step 5 until you have data for 10 different grid segments (and the table is filled out).
These 10 grid segments represent a sample. Gathering data from a randomly selected sample
of a larger area is called sampling.
6. Find the total number of sunflower plants for the 10 segment sample. This is an estimation
based on a formula. Add all the grid segment sunflowers together and divide by ten to get an
AVERAGE number of sunflower plants per grid segment. Record this number in the table.
Multiple the average number of sunflower plants by 100 (this is the total number of grid
segments) to find the total number of plants in the meadow based on your sample. Record this
number in your data table.
7. Now count all the sunflower plants actually shown in the meadow. Record this number in the
data table. Divide this figure by 100 to calculate the average number of sunflower plants per
each grid.
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Random Sampling Data
Grid Sigment
(number - letter)
Actual Data
Number of Sunflowers
Total number of Sunflowers ______
(count by hand)
Average number of Sunflowers
(divide total by 10) Per grid _____
Total Number of Sunflowers
Average (divide total by 10)
Total number of plants in meadow
(multiply average by 100)
Analysis:
1. Compare the total number you got for sunflowers from the SAMPLING to the ACTUAL count. How
close are they?
2. Why was the paper-slip method used to select the grid segments?
3a. A lazy ecologist collects data from the same field, but he stops just on the side of the road and just
counts the 10 segments near the road. These 10 segments are located at J 1-10. When he submits his
report, how many sunflowers will he estimate are in the field?
b. Suggest a number why his estimation differs from your estimation.
4. Population Sampling is usually more effective when the population has an even
dispersion pattern. Clumped dispersion patterns are the least effective. Explain why this would be the
case.
5. Describe how you would use Sampling to determine the population of dandelions in your yard.
6. In a forest that measures 5 miles by 5 miles, a sample was taken to count the number of silver maple
trees in the forest. The number of trees counted in the grid is shown below. The grids where the survey
was taken were chosen randomly. Determine how many silver maple trees are in this forest using the
random sampling technique. Show your work!
7
3
5
11
9
17
Human Population
Estimated Human Population Size
Year Population in Millions
1. In the space at the bottom of this page graph the Human
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Population (in millions) over Time (Year).
200
190
400
190
600
200
800
220
1000
265
2. Add a dashed line of your projection for the size of the
1200
360
human population through the year 2100.
1400
350
1600
545
1800
900
1850
1210
1900
1625
1950
2556
3. What reasons do you have for your projection?
2000
6060
2007
6625
2025*
7965
* Projected by the Population Reference Bureau
8000
0
0
2100
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Human Population Growth: Power of the Pyramids
1. The table below represents the population in thousands of each age group within each gender
for the United States in 2007. In order to construct a population pyramid you must first
calculate the percentage of the population in each subgroup. For example, the United States’s
total population in 2007 was 301,140,000. The population of males up to age four was
10,635,000.
10,635,000_ = 0.035 or 3.5%
301,140,000
2. Complete these calculations for each age group in the table below.
Age Group Male Population Male Population % Female Population Female Population %
0-4
10,635
10,181
5-9
10,156
9,718
10-14
10,360
9,880
15-19
11,115
10,551
20-24
10,794
10,241
25-29
10,570
10,242
30-34
9,786
9,596
35-39
10,558
10,491
40-44
10,878
11,003
45-49
11,280
11,567
50-54
10,272
10,721
55-59
8,855
9,424
60-64
6,889
7,531
65-69
5,027
5,758
70-74
3,857
4,727
75-79
3,084
4,208
80+
3,891
7,298
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3. Using the space at the bottom of this page, construct a population pyramid for the United
States using the data in the table you constructed. An example of a population pyramid
is provided below. The figures along the X-axis represent the calculated percentages of
the population, while points along the Y-axis represent age groups. A line drawn down
the middle of the graph separates the male and female populations. You should use a
different color for each side of the graph.
80+
75-79
70-74
65-69
60-64
55-59
50-54
45-49
40-44
35-39
30-34
25-29
20-24
15-19
10-14
5-9
0-4
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Using the U.S. population pyramid you constructed answer the following questions.
4. Is there a relatively large or a relatively small gender difference in the youngest age groups?
Why is this the case?
5. Is there a relatively large or a relatively small gender difference in the oldest age groups? Why
is this the case?
6. What is the cause of the bulge in the middle of the pyramid?
7. Go to the following website:
http://www.census.gov/population/international/data/idb/informationGateway.php
Select Report POPULATION PYRIMID GRAPH.
Select the 2000, 2014 and 2050, bu holding down the control key while selecting.
Click the “Submit” button.
Select the ANIMATE press play button.
Using these graphs answer the following questions.
8. What is the biggest change in the population comparing 2000 and 2050? Why is this?
9. Click the back button and select the country Kenya. Select years 2000, 2007, 2014. Click the
“Submit” button. Select the year 2007. Make a simple illustration of the shape of this graph
below.
10. How does the population pyramid of Kenya compare to that of the United States in 2007
(your graph)?
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11. Kenya is a developing country as is India. Find what the pyramid looks like for India in the
year 2007. Sketch the shape of this graph of India below.
12. All developing countries share this shape of their population pyramid. Why is this?
13. As you have seen Germany and Russia are experiencing negative growth. Find what their
graphs look like and sketch a representative graph below.
14. The United States, Japan, and China are experience growth but it is slow growth. Find what
their graphs look like and sketch a representative graph below.
15. Make a hypothesis on what the World’s population pyramid looks like by sketching it
below. How did you come to this hypothesis?
In the hour it has taken you to complete this worksheet, 16,000 people have been born and
7000 people have passed away.
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Population Dynamics Standard Practice
1.
The following data chart the growth of a population of deer on a small protected island off the coast
of Alaska, recorded over a 50-year period:
Year
1941
1945
1950
1955
1960
1965
#
92
151
295
603
861
920
Year
1970
1975
1980
1985
1990
1995
#
814
765
688
740
729
738
a) Graph the growth of the deer population. Label the axes. How would you describe the overall shape
of the graph? (you may use Excel for this or blank graph paper)
b) What happened to the population during the 1960’s and early 1970’s?
c) What may have caused the population density to level off?
d) What is your estimate of the carrying capacity of the island for deer?
e) What is the biological term for this kind of population growth?
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5B Food Sustainability
Task: Using the resources given and research on the internet create a project that will explain the
difference between industrial and sustainable farming and agriculture practice. Explain the pros and
cons of each type of practice and how someone can make food choices that use agriculture that
support a sustainable plan.
DON'T ASSUME
Organic = Sustainable
All Industrial Farms = Non-Sustainable
Videos that you can watch to help you understand the big picture, opportunities to watch in class will
be provided.
Fresh http://www.freshthemovie.com/
Ingredients http://www.ingredientsfilm.com/
Checklist:
 I explained sustainable farming and agriculture citing multiple sources of evidence to support
my explanation.
 I explain industrial farming and agriculture citing multiple sources of evidence to support my
explanation.
 I can identify the pros and cons of sustainable farming and agriculture.
 I can identify the pros and cons of industrial farming and agriculture.
 I can identify poor consumer choices when it comes to supporting sustainable farming and
agriculture.
 I can identify valid and realistic consumer choices when it comes to supporting sustainable
farming and agriculture.
 I can identify "sustainable" agriculture schemes that result in lining the pockets of the
business industry but do not support sustainable agricultural practices.
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