Lesson 3 | Adaptation and Evolution
Student Labs and Activities
Page
Launch Lab
45
Content Vocabulary
46
Lesson Outline
47
MiniLab
49
Content Practice A
50
Content Practice B
51
Language Arts Support
52
School to Home
54
Key Concept Builders
55
Enrichment
59
Challenge
60
Lab A
63
Lab B
66
Lab C
69
Chapter Key Concepts Builder
70
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Heredity and How Traits Change
Name
Date
Launch Lab
Class
LESSON 3: 10 minutes
How does variation help survival?
Mutations cause differences, or variations, in traits. How can variations help or hinder an
organism’s survival?
Procedure
1. Read and complete a lab safety form.
2. Examine various cell phones or
pictures of cell phones. Note the
different features that each cell phone
offers. For example, some might have
a full keyboard, some might have a
camera, and some might have a
hands-free option.
3. Make a data table in the Data and
Observations section below, and
record your observations about the
characteristics of each phone.
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Data and Observations
Think About This
1. What are some of the variations among the phones?
2. If each variation represents a mutation in the population of phones, how might each
mutation have a positive or a negative impact on the population?
3.
Key Concept How do you think the development of new characteristics might
help a population of organisms survive?
Heredity and How Traits Change
45
Name
Date
Class
Content Vocabulary
LESSON 3
Adaptation and Evolution
Directions: Unscramble each word. Then write each term on the line before its definition.
1. vurvise
2. voonsaretinc goobily
3. neinitxtoc
4. notovelui
5. aiotapdnat
6. ionratvia
7. lartuna leensciot
8. uconedirt
10. a process by which individuals with traits that help them
survive in their environment live longer, compete better,
and reproduce more than individuals without these traits
11. a branch of science focused on studying why some species
are in trouble and what can be done to save them
12. an inherited trait that increases the chance of survival
and reproduction
13. to bring a substance into a habitat or population
14. to remain alive
15. the death of all members of a species
16. change over time
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Heredity and How Traits Change
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9. a slight difference in an inherited trait
Name
Date
Class
Lesson Outline
LESSON 3
Adaptation and Evolution
A. Mutations, Variation, and Natural Selection
1. Mutations can lead to changes in
, which means that
mutations can produce differences among individuals.
2. Slight differences in inherited traits among individuals in a population are
called
.
3. In the 1970s, scientists observed that the
size of a group
of finches changed as a result of changes in their food supply.
4.
is the process by which individuals with variations that
help them survive in their environment live longer, compete better, and reproduce
more than those individuals without these variations.
B. Adaptations
1. An inherited trait that increases an organism’s chance of surviving and reproducing
in a particular environment is called a(n)
.
2. Adaptations can be structural, functional, or
.
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a. The flap of skin that enables a flying squirrel to glide through the air is an
example of a(n)
adaptation.
b. Structural adaptations involve
characteristics, such as
color or shape.
c. The smaller
of desert plants are an adaptation that
helps them reduce water loss in a dry environment.
d. Functional adaptations involve
systems that affect an
organism’s physiology or biochemistry.
e. To survive with a short
season, the alpine snowbell
produces flower buds at the end of the previous season.
f.
adaptations, such as migration, involve the ways an
organism behaves or acts.
g. Animal species that migrate to find adequate food and suitable temperatures
survive and
Heredity and How Traits Change
more successfully.
47
Name
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Class
Lesson Outline continued
C. Evolution of Populations—Why Traits Change
1. When a(n)
trait has become more frequent in a
population, the population has adapted and evolved.
a. Another way to describe
is change over time.
b. Evolution by natural selection is a way that
change
over time.
c. Species can look and behave differently than their ancestors because the
frequency of
traits changes over time.
2. The evolution of antibiotic-resistant
is a modern
example of change over time.
a. Bacteria that survive when exposed to an antibiotic are
called
.
b. Antibiotic-resistant bacteria are of great concern to scientists because they can
cause deadly
.
D. Extinction and Conservation Biology
1. When a population lacks variation among its individuals and the environment
changes, the population might lose its ability to
a.
.
occurs when the last individual of a species dies.
b. New species introduced into many habitats make it difficult for some
species to survive and reproduce.
2. The branch of biology that studies why many species are in trouble and what can
be done to save them is called
biology.
3. Scientists introduced several female panthers from a population in Texas into the
Florida population to increase genetic
population.
48
in the Florida
Heredity and How Traits Change
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successfully and fail to
Name
Date
Class
MiniLab
LESSON 3: 15 minutes
How can you observe change over time?
Analyze and Conclude
Finch Beak Size,
Galápagos Islands
Number of Finches
The data collected by the scientists who studied
the finches on the Galápagos Islands is shown in
the graphs on the right. Recall that the scientists
measured the beak size of the adult finches in
1976 then, in 1978, measured the beaks of all the
birds that survived the drought. Examine the
graphs, and then answer the following questions.
90
1976
60
30
0
1. Hypothesize Write a hypothesis that explains
6
7
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2. Analyze What change occurred in the average
beak size of the finch population after the
drought of 1977?
Number of Finches
why some birds might have survived the
drought of 1977, while most birds did not.
12
8
9
10
Beak Depth (mm)
11
8
9
10
Beak Depth (mm)
11
1978
8
4
0
6
7
3. Infer How might differences in beak size have affected which birds survived the
drought? Do the data in the graphs support your hypothesis? If not, revise your
hypothesis to reflect this information.
4.
Key Concept Infer how the change in the environment might have affected the
beak size of the finch population for the years following 1978.
Heredity and How Traits Change
49
Name
Date
Class
Content Practice A
LESSON 3
Adaptation and Evolution
Directions: On the line before each definition, write the letter of the term that matches it correctly. Each term is
used only once.
1. slight differences in inherited traits among a
population
2. the process by which individuals with traits that
help them survive in their environment live
longer, compete better, and reproduce more than
those individuals without these traits
3. change over time
A. adaptation
B. conservation biology
C. evolution
D. extinction
E. natural selection
F. variation
4. when the last individual of a species dies
5. a branch of biology that studies why many
species are in trouble and what can be done to
save them
6. an inherited trait that increases an organism’s
chance of surviving and reproducing in a
particular environment
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Heredity and How Traits Change
Name
Date
Class
Content Practice B
LESSON 3
Adaptation and Evolution
Directions: Identify each statement from the list as an example of variation or natural selection. Write the letter
of the statement beneath the correct heading.
A. Over time, the average height of a sunflower population becomes tall in order to
receive more sunlight.
B. Birds of the same species in a population have slight differences in nest-building skills.
C. In a population, some sunflowers are tall and others are short.
D. In two years, the average beak size of a population of birds increases so the birds are
able to eat large, hard seeds.
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Variation
Natural Selection
Directions: Identify each statement from the list as an example of structural adaptation, functional adaptation,
or behavioral adaptation. Write the letter of the statement beneath the correct heading.
A. A flying squirrel has a flap of skin that allows it to glide distances of up to 45 m and
escape from predators.
B. Caribou, birds, whales, and butterflies migrate south for the winter to find adequate
food and suitable temperatures to survive and reproduce more successfully.
C. The alpine snowbell has adapted to survive with a short growing season.
D. The reduced size of leaves on desert plants helps reduce water loss in a dry
environment.
Structural Adaptation
Heredity and How Traits Change
Functional Adaptation
Behavioral Adaptation
51
Name
Date
Language Arts Support
Class
LESSON 3
Word-Meaning Activity: Using Antonyms
The prefix anti– or ant– means “opposite.” The suffix –onym means “word” or “name.” An
antonym is a word that means the opposite of another word. Fast and slow are antonyms.
Liquid and solid are also antonyms.
Directions: On the line before each word in the numbered column, write the letter of the correct antonym.
1. dominant
A. sexual
2. homozygous
B. phenotype
3. similarity
C. survival
4. asexual
D. destruction
E. heterozygous
5. multicellular
F. difference
6. extinction
G. unicellular
7. genotype
H. recessive
8. conservation
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Heredity and How Traits Change
Name
Date
Language Arts Support
Class
LESSON 3
Word-Study Activity: Words with a silent h
Some words are spelled with an h that is not pronounced in American English when the
word is spoken aloud. These words have a silent h. For example, the h in the word herb is
silent. In contrast, the h in the word happy is pronounced.
Directions: Read each sentence below. Underline words that are spelled with a silent h. Circle words that are
spelled with a pronounced h.
1. Human height is controlled by polygenic inheritance.
2. He was an honest and honorable person.
3. Sex-linked traits are carried on the X or Y chromosomes.
4. An heir is someone who receives an inheritance of possessions or is of a social status.
The scientific use of the term inheritance refers to the passing of alleles from parents to
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
offspring.
5. Mendel conducted many monohybrid crosses.
6. He crossed many sets of heterozygous pea plants that produced green pea pods.
7. Mendel’s true-breeding green-pod and yellow-pod pea plants were homozygous for
pod color.
8. It can take hours of study to learn how to use a Punnett square.
Heredity and How Traits Change
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Name
Date
Class
School to Home
LESSON 3
Adaptation and Evolution
Directions: Use your textbook to respond to each statement.
1. Some traits allow organisms to survive and reproduce through the process
of natural selection.
Describe a sequence of events that shows natural selection over a period of time.
2. Adaptations increase an organism’s chances of surviving and reproducing.
Give an example of a type of adaptation that allows an organism to survive in a
particular environment.
List some reasons for extinction.
4. Conservation biology studies species in trouble and proposes solutions to
save them.
Describe the efforts of scientists to save the Florida panther population.
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Heredity and How Traits Change
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3. Extinction occurs when the last individual of a species dies.
Name
Date
Class
Key Concept Builder
LESSON 3
Adaptation and Evolution
Key Concept How does natural selection occur?
Directions: Use the diagram to answer each question or respond to each statement on the lines provided.
Figure 1
1 Variation
Figure 2
2 Inheritance
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Figure 3
3 Competition
Figure 4
4 Natural Selection
This diagram shows the process of natural selection.
1. Describe the variations among the sunflowers in Figure 1.
2. Why do you think the tall sunflowers started to die in Figure 3?
3. What might happen to the sunflowers in Figure 4 if resources become plentiful?
Heredity and How Traits Change
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Name
Key Concept Builder
Date
Class
LESSON 3
Adaptation and Evolution
Key Concept How does natural selection occur?
Directions: In the space below, write a descriptive story about a fictional species of bird. Include examples of
variations among the bird population and an example of natural selection in your story. Be creative.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
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Heredity and How Traits Change
Name
Date
Key Concept Builder
Class
LESSON 3
Adaptation and Evolution
Key Concept What is an adaptation?
Directions: Circle the term in parentheses that correctly completes each sentence.
1. The traits of surviving individuals become (more common/less common) as the
survivors reproduce and pass the genes for their traits to their offspring.
2. Structural adaptations involve physical characteristics such as
(color and shape/migration patterns).
3. Many desert plants have leaves that are reduced in size to help (increase/reduce)
water loss in a dry environment.
4. Functional adaptations involve (internal/external) systems that affect an organism’s
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
physiology or biochemistry.
5. Behavioral adaptations like migration involve the ways an organism
(passes on traits/behaves or acts).
6. An adaptation is a(n) (learned/inherited) trait that increases an organism’s chance of
surviving and reproducing in a particular environment.
7. The alpine snowbell blooming while it is surrounded by snow is an example of
(functional/behavior) adaptation.
Heredity and How Traits Change
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Name
Date
Class
Key Concept Builder
LESSON 3
Adaptation and Evolution
Key Concept Why do traits change over time?
Directions: Answer each question or respond to each statement on the lines provided.
1. What is evolution?
2. How are evolution and natural selection related?
3. Describe how evolution relates to a species and its ancestors.
4. What is a modern example of change over time?
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5. What is extinction?
6. What events can lead to extinction?
7. What is conservation biology?
8. Give an example of how conservation biology helps species in danger of extinction.
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Heredity and How Traits Change
Name
Date
Enrichment
Class
LESSON 3
Sickle Cell Anemia
Sickle cell anemia is a blood-based,
inherited disease that is caused by a single
mutation in the gene for hemoglobin.
Hemoglobin is the protein that carries
oxygen in the blood. The homozygous
dominant genotype is HbAHbA. This
person is healthy. The homozygous
recessive genotype is HbSHbS. This person
is completely affected by sickle cell disease.
However, the heterozygous genotype
HbAHbS has a defective allele and a normal
allele. This individual is rarely affected by
sickle cell trait.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
The Origin of the Disease
The origin of the disease has been traced
to central Africa, where the first known case
is thought to have occurred in the 1920s. It
surely existed earlier, but it was not until
then that the disease could be diagnosed.
In central Africa, homozygous sickle cell
disease occurs in approximately 25 percent
of the population. However, heterozygous
sickle cell trait occurs in approximately
40 percent of the population. Scientists of
the day wondered how natural selection
had not acted against the sickle cell allele
and reduced its frequency. Why was this
potentially fatal allele so common in
central Africa and almost unknown in
other parts of the world?
A Selective Advantage
It was observed that the sickle cell trait
(heterozygous) was three times more
common among African families than
African-American families in the United
States. But sickle cell disease (homozygous)
was less common in Africa than in the
United States. It was also observed that the
high frequency of the trait coincided with
the distribution of malaria. Malaria is a
disease characterized by cycles of chills,
fever, and sweating. It is caused by a
protozoan in red blood cells, which is
transmitted to humans by the bite of an
infected mosquito. Malaria kills about
1.2 million people per year worldwide.
When the protozoan infects a red blood
cell of a heterozygote, the cell sickles and
is removed from the blood by the spleen
along with the protozoan. Thus, the
individual is spared the ravages of malaria.
The person with healthy cells does not
have this advantage. The cells do not sickle
and the protozoan remains in the blood
to reproduce. Interestingly, malaria kills
both homozygotes—those who are healthy
without the defective allele, and those who
are affected by two defective alleles. Thus,
in malaria prone areas, sickle cell trait is a
survival trait. The selective advantage is not
present in areas not prone to malaria.
Applying Critical-Thinking Skills
Directions: Answer each question or respond to each statement.
1. Consider How could an inherited disorder possibly be a survival defense against another
disease?
2. Infer the reason that sickle cell disease occurs with similar frequency as sickle cell trait
in the United States.
Heredity and How Traits Change
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Class
Challenge
LESSON 3
Antibiotics and Antibacterial Soap
Antibiotics are used to treat bacterial infections. Usually, antibiotics effectively kill the
bacteria causing the infection; however, a few bacteria in a population might have a mutation
that enables them to survive. These bacteria are said to be resistant to that antibiotic. When
the antibiotic-resistant bacteria reproduce, their offspring are likely to also be resistant.
Write a Newspaper Article
Write an article that will help the students in your school learn about antibiotic resistance
and the proper use of antibiotics and antibacterial products. Research your topics, and
discuss the following:
1. Explain what antibiotics are effective against and when they do not work.
2. Tell readers why they should take an entire prescription as directed. Tell what effect not
taking the entire prescription can have on the future effectiveness of antibiotics against
the same organism.
3. Research how common bacteria can become immune to antibiotic medication and
antibacterial soaps and then become hard to treat.
Remind them to scrub thoroughly so the most resistant bacteria do not remain behind
on hands and under nails.
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Heredity and How Traits Change
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4. Inform patients that plain soap and water is as cleansing as antibiotic soap and water.
Name
Date
Lab A
Class
1 class period
What’s in a face?
The traits that make us each look different are caused by thousands of combinations of
different pairs of alleles. Each gene in a pair comes from one parent, and each gene is
selected randomly.
Ask a Question
How can you model the allele contribution of each parent to determine the genotype and
the phenotype of an organism’s traits?
Materials
coin
Safety
Make Observations
1. Read and complete a lab safety form.
2. Obtain your group number. If you are in group 1, you will make a female face. If you
are in group 2, you will make a male face.
3. On a separate sheet of paper, draw a table like the one shown in your textbook. The
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
table lists the traits you will use to make your face.
For the first trait, flip a coin to determine the allele contributed by the mother.
For all traits, heads will represent the dominant allele, and tails will represent the
recessive allele.
Record your results.
4. Flip the coin a second time to determine the allele contributed by the father.
Record your results.
Record the genotype for this trait.
5. Repeat steps 3 and 4 for each of the remaining traits.
6. Using the genotypes, determine and record the phenotype your face will express for
each trait.
Draw your face.
Heredity and How Traits Change
63
Name
Date
Class
Lab A continued
7. Find a partner who has created a face of the opposite gender of
yours.
Based on the genotypes of each face, determine the possible
genotypes of a second generation.
Use Punnett squares to track the different genotypes.
8. For each trait, determine and record the most probable phenotype. If there is an
equal chance of either genotype, flip a coin to decide which phenotype you will use.
Form a Hypothesis
9. Form a hypothesis to explain the relationship between the genotypes of the first
generation and the phenotype of the second generation. Predict the phenotype of
your second-generation face.
Test Your Hypothesis
generation face for the first trait. Heads represents the first allele in the genotype.
Tails represents the second allele in the genotype.
Record your results.
11. Repeat step 10 to determine the allele contributed by the father.
Record the genotype for this trait.
12. Repeat steps 10 and 11 for the remaining traits.
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Heredity and How Traits Change
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10. Flip the coin to determine which allele the mother will contribute to the second-
Name
Date
Class
Lab A continued
13. Using the genotypes, determine and record the phenotype your face will express for
each trait.
Draw your face below.
14. Compare the phenotype of the second-generation face to your hypothesis.
Analyze and Conclude
15. Analyze Did your results match your hypothesis? Why or why not?
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16. Critique Were there some genetic combinations that were more likely for the
offspring than others?
Were there some combinations that were not possible? Why?
17.
The Big Idea How are genes and traits passed on
from parents to offspring?
Remember to use scientific
methods.
Make Observations
Ask a Question
Form a Hypothesis
Test your Hypothesis
Communicate Your Results
With your partner, make a poster that shows the cross
between the two faces and the second-generation face that
resulted. Include information about how you determined
the genotypes and the phenotypes for each trait.
Heredity and How Traits Change
Analyze and Conclude
Communicate Results
65
Name
Date
Lab B
Class
1 class period
What’s in a face?
The traits that make us each look different are caused by thousands of combinations of
different pairs of alleles. Each gene in a pair comes from one parent, and each gene is
selected randomly.
Ask a Question
How can you model the allele contribution of each parent to determine the genotype and
the phenotype of an organism’s traits?
Materials
coin
Safety
Make Observations
1. Read and complete a lab safety form.
2. Obtain your group number. If you are in group 1, you will make a female face. If you
are in group 2, you will make a male face.
3. On a separate sheet of paper, draw a table like the one shown in your textbook. The
4. Flip the coin a second time to determine the allele contributed by the father. Record
your results. Record the genotype for this trait.
5. Repeat steps 3 and 4 for each of the remaining traits.
6. Using the genotypes, determine and record the phenotype your face will express for
each trait. Draw your face below.
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Heredity and How Traits Change
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
table lists the traits you will use to make your face. For the first trait, flip a coin to
determine the allele contributed by the mother. For all traits, heads will represent the
dominant allele, and tails will represent the recessive allele. Record your results.
Name
Date
Class
Lab B continued
7. Find a partner who has created a face of the opposite gender of yours. Based on the
genotypes of each face, determine the possible genotypes of a second generation. Use
Punnett squares to track the different genotypes.
8. For each trait, determine and record the most probable phenotype. If there is an equal
chance of either genotype, flip a coin to decide which phenotype you will use.
Form a Hypothesis
9. Form a hypothesis to explain the relationship between the genotypes of the first
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
generation and the phenotype of the second generation. Predict the phenotype of your
second-generation face.
Test Your Hypothesis
10. Flip the coin to determine which allele the mother will contribute to the secondgeneration face for the first trait. Heads represents the first allele in the genotype. Tails
represents the second allele in the genotype. Record your results.
11. Repeat step 10 to determine the allele contributed by the father. Record the genotype
for this trait.
12. Repeat steps 10 and 11 for the remaining traits.
13. Using the genotypes, determine and record the phenotype your face will express for
each trait. Draw your face below.
Heredity and How Traits Change
67
Name
Date
Class
Lab B continued
14. Compare the phenotype of the second-generation face to your hypothesis.
Analyze and Conclude
15. Analyze Did your results match your hypothesis? Why or why not?
16. Critique Were there some genetic combinations that were more likely for the offspring
than others? Were there some combinations that were not possible? Why?
17.
The Big Idea How are genes and traits passed on
from parents to offspring?
Make Observations
Ask a Question
Form a Hypothesis
Communicate Your Results
Test your Hypothesis
With your partner, make a poster that shows the cross
between the two faces and the second-generation face that
resulted. Include information about how you determined
the genotypes and the phenotypes for each trait.
Analyze and Conclude
Communicate Results
Extension
Choose one of the facial characteristics and do several genetic crosses to create many
offspring. Then draw a pedigree that illustrates the presence of the trait over the two
generations.
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Heredity and How Traits Change
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Remember to use scientific
methods.
Name
Date
Class
Lab C
Modeling Multiple Alleles
Directions: Use the information and data from the Lab What’s in a face? to perform this lab.
You have learned that an individual’s traits are determined by alleles that they get from
their parents. In Lab B, you used coin tosses to model how the allele contributions from
each parent determine the genotype and the phenotype of an individual’s facial traits.
Design a procedure to model the inheritance of multiple alleles in human ABO blood types.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Please note that you must complete Lab B before beginning Lab C. Also, have your teacher
approve your design and safety procedures before beginning your experiment.
Heredity and How Traits Change
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Name
Date
Class
Chapter Key Concepts Builder
Heredity and How Traits Change
End-of-Chapter Practice
Directions: Work with a partner to create a pamphlet that explains the extinction or near extinction of a species.
Choose a species that has faced extinction or is extinct. Explore the following questions:
Was the species’ habitat altered or destroyed?
Was the species hunted to extinction?
Were new species introduced into the habitat making it difficult for the native species to survive
and reproduce?
Did an understanding of genetics help restore the population?
Then, as a pair, determine how you will organize the pamphlet to explain the extinction or
near extinction of the species. Think about:
Materials you will need:
Design of the pamphlet:
Individual responsibilities:
After your pamphlet is complete, present your findings to the class and display your
pamphlet for students to see.
Pamphlet Requirements:
• well-organized, neat, and easy to understand
• comprehensive with good use of visuals and/or diagrams
• Both partners contribute equally.
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Heredity and How Traits Change
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What role did conservation biology play in preventing the extinction or trying to prevent it?