1. 2/6 A/B Day
LEQ: What things can change the impact
that a chemical has on a living thing?
1. What is a carcinogen?
2. What causes FAS?
3. What disease is associated with cholesterol?
4. What disease is associated with levels of
glucose and insulin in the body?
5. What disease is associated with inflamed or
swollen bronchi?

2. Today’s LEQ: What things can change the
impact that a chemical has on a living
thing?
By the end of today, you should be able to…
1. Describe how changing the
dose, exposure, concentration, potency, and
concentration of a chemical can change the
impact a chemical has on an organism.
2. Explain why the eagle population dropped so
dramatically in the United States!

3. Focus Vocabulary:
97. Dose
98. Potency
99. Exposure
100. Susceptibility
101. Concentration

4. Stop-and-Jot:
What do you know about bald eagles?

5. Eagles in trouble…
The bald eagle, our national bird, is the
only eagle native to North America.
Bald eagles are found throughout most of the United
States. Their most important food source is fish, which
they catch with their talons. Beginning in the 1950s and
60s, the bald eagle population started to decrease, and in
1967, the bald eagle was declared an endangered
species. Scientists eventually discovered the cause of the
rapid decline in the bald eagle population, but it wasn’t
until 2007 that the bald eagle was officially removed from
the endangered species list. What was the cause of the
near-extinction of bald eagles? Stay tuned to find out!

6. Possible Killers: Make a hypothesis
Hunting by humans
Hunting by other animals
Disappearing food source
Harmful chemicals in habitat
Global Warming/Climate change
Disappearing habitat (Deforestation)
Disease

7. 1. When was the Bald Eagle population the lowest?
2. What do you think caused the Bald Eagle population to suddenly
decrease?
3. Why do you think it took longer for the Bald Eagle population to go
back up again?
Eagles (thousands)
Number of Bald
1940 ‘50 ’60 ‘70 ‘90 2000 ‘10

8. Make a FRAYER DIAGRAM for each VOCAB WORD
(dose, potency, exposure, susceptibility, concentration)
DEFINITION: Sentence:
(CREATE YOUR
(Write definition of
OWN SENTENCE
the word from the
using the word)
station)
EXAMPLE:
DOSE
CLUE!!!
Come see me—I will give
(Write the example you the clue to help solve
of the word from the mystery! Copy all of
the station) the important clues here!

9. Discovery Education
DDT: A Threat to America’s Bald Eagles

10. Let’s Practice: Fill in the blank!
Beginning in the 1950’s, scientists started spraying large
DOSES
_________ of DDT into the environment. DDT is a chemical
with a very high POTENCY meaning it is extremely
________,
powerful, even in small amounts. As humans continued to
spray DDT into the environment, we quickly learned that the
_______________ of the chemical increased as it traveled
CONCENTRATION
higher up the food chain. Small organisms, like
insects, would only have a small percentage of DDT in their
bodies, but the organisms at the top of the food chain would
eat millions of smaller animals, which would greatly increase
the amount of the chemicals in their bodies. Organisms
EXPOSURE to the chemical continued to increase because the
________
chemical did not disappear once it was sprayed into the
environment. Because different organisms have a different
SUSCEPTIBILITY
______________ to the chemical, not all of the eagles died.

11. EOG QUESTION
Which factor best explains why some people
will develop cancer and others will not after
being exposed to the same high levels of a
harmful chemical?
a) concentration of the chemical
b) potency of the chemical
c) individual susceptibility to the chemical
d) individual exposure to the chemical

12. DDT: Pros and Cons
Do you think we should lift the
bans on DDT?
Why or Why not?!

13. Summarizer:
1. Increased exposure to a chemical would
[increase/decrease] your chance of getting sick.
2. Would you rather be exposed to a high dose of a
dangerous chemical or a low dose of a dangerous
chemical?
3. If everyone is exposed to the same amount of a
dangerous chemical, why won’t everyone get sick?
4. Eagles have a [higher/lower] concentration of DDT
in their bodies than insects do.
5. Which would you predict to be more potent:
bleach or water? Why?