# 9.10 Population Pyramids

```Welcome back!
Turn in your Ecosystem Diagram to the inbox, if you haven’t
Warm-Up 9/10-9/11
Currently 7.2 billion people live on the Earth.
a. How many more people do you think the Earth
can support?
b. Why do you think it can support that many?
c. What is going to happen when we reach the
point where earth can no longer support all the
people?
Learning Targets
 I can calculate population density, birth rate, death
rate, growth rate, and doubling time.
 I can create an age structure diagram and use it to
predict population trends for a given country.
Chapter One HW Review
 Get a textbook for your table.
 Go around the table sharing multiple choice answers
and discuss any you are struggling with.
 Be prepared to share any you can’t get as a group!
 Next book HW….there will be an open-note quiz!
Module One Multiple Choice
1. Answer: D (I and III only)
Why? Fracking, which extracts natural gas from the
ground, decreases coal use because people can use
Why? Abiotic means non-living, and rocks are nonliving 
Module One Multiple Choice
Why? Ecosystems include biotic and abiotic
components, including humans
Why? The use of fire by Native Americans allowed
grasslands, a whole new ecosystem to form. This was a
positive impact.
Module 2 Multiple Choice
1. E
Why? Pollution in a LOCAL stream isn’t enough
information to indicate overall global health
2. A
Why?
500 acres x .405 ha = 200 ha (line up and cancel units!)
1 acre
Module 2 Multiple Choice
3. E
Per capita = per person
There are 4x as many people in developing countries but they only
use 10% more meat and fish. Per person, developed countries must
consume 4x more fish.
4. C
640,000 ha x 1 year x
1 year
365 days
1 day = 73 ha
24 hrs.
5. D
Why? Ecological footprint includes ALL consumption and by
products of that consumption.
Module 3 Multiple Choice
1. B
Why? Scientists have to observe a phenomenon before
2. B
Precision = able to do the same thing over and over
Accuracy = able to give a measurement that is true
Device 1 was far from the actual 400 ppm, but right
around 416 each time.
Module 3 Multiple Choice
3. D
Even though Device 2 wavers a bit, it is very close to the
true amount of lead. It is accurate and precise.
ppm = parts of lead in a million parts of water
4. A
Why? Actually, I think studying natural systems can be
dangerous. This is a terrible question written to match
the book.
Module 3 Multiple Choice
5. D
Why? A control group needs to be the same as your
experimental group, except it isn’t being exposed to the
manipulated variable.
Ex: You slam your hand in the car door. Both hand are
under the same conditions, except the manipulated
variable is the impact of a car door. You compare your
good hand (control) to the bad hand (experimental)
End of Chapter Questions
Q and A
Why?
1. D
Reduced human population growth hasn’t happened
2. B
They all sound a little true….watch out for ONLY, ALWAYS, etc.
3. B
Both population and food production have increased, although
population has increased by much more
4. B
A- it’s from the ice, not the air C- Can’t replicate; once the sample is
taken, it’s contaminated D- Only part of an ecological footprint
E- This is long term temp, NOT seasonal
5. C
consuming at that rate. Again, a question where you pick the BEST
6. C
A natural law is true every time (i.e. gravity), while a theory COULD be
disproven (although it has a TON of evidence)
End of Chapter Questions
Q and A
Why?
7. E
Some forest fires are not anthropogenic (caused by man)- lightning,
etc.
8. B
1950- 250 grain per capita 2000- 300 (50/300 = 20%)
9. E
From the reading on page 10
10. D
A null hypothesis is a statement you are trying to prove wrong. The
statement that caffeine has no effect on pulse rate is your baseline
11. A
B doesn’t match the data; C, D, E are all inferences/opinions
Chapter 7 Homework
 Due Monday the 21st/Tuesday the 22nd.
 Document on my website under Lab/Activities/HW
Who are all these people?
What is their life like?
 Find the document called “world of 100 people” on
my website
 Fill it in with your best guesses!
 http://www.economist.com/blogs/graphicdetail/2014/
11/daily-chart-10
Local/Nat’l Pop. measurements
We measure populations using a few tools:
Population density = population
area
Ex: Maple Valley’s density in 2014 was 3966 people/1 sq. mile
Birth Rate = births in one year
total population
x 100
Death Rate = deaths in one year
total population
x 100
Local/nat’l Pop. Measurements
 Immigration = migration of people into a country
 Emigration = migration of people out of a country
Population growth rate =
(births + immigration) – (deaths + emigration) x 100
total population
 What is the population growth rate of Maple Valley if there
were 259 births, 150 immigrants, 199 deaths, and 75 emigrants
in 2014? The total population is 24,512.
 Now go back and calculate the birth and death rates!
Rule of 70
 Calculate Doubling Time
70
= Doubling Time
growth as a %
(growth rate is called r)
 In 1980 a country has one million people and a 2%
growth rate, in what year will its population have
doubled?
 70/2% = 35
1980+35 = 2015
Global Population Measurements
 It is easier to calculate birth and death rate per 1,000
people than per 7.2 billion people
CBR (crude birth rate) = births per 1,000 people
CDR (crude death rate) = deaths per 1,000 people
Global population growth= (CBR – CDR)
10
Why no immigration or emigration?
Age Structure Diagrams!
What is an Age Structure Diagram?
Vertical Axis - Age Groups
Elderly dependents
Working population
Young dependents
Horizontal Axis- Population Numbers
Age Structure Diagrams
 Profile of country’s residents
 Gives us a glimpse into large-scale health events and
future growth/decline
US Baby Boom after WWII
Due Next Time
 Power of the Pyramids Activity
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