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Traits and
Heredity
Teacher's Guide
Editors:
Brian A. Jerome Ph.D.
Stephanie Zak Jerome
Assistant Editors:
Louise Marrier
Hannah Fjeld
Graphics:
Fred Thodal
Heidi Berry
Brian Bliven
Emily Merkert
Lyndsey Canfield
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Use and Copyright:
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Traits and Heredity
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Table of Contents
Visual Learning Company 1-800-453-8481
A Message from our Company
2
Viewing Clearances
2
Use and Copyright
2
National Standards Correlations
4
Student Learning Objectives
5
Assessment
6
Introducing the Program
7
Program Viewing Suggestions
7
Video Script
8
Answer Key to Student Assessments
12
Answer Key to Student Activities
13
Pre-Test
14
Post-Test
16
Video Review
18
Vocabulary
19
Writing Activity
20
Dominant and Recessive Traits
21
Acquired vs Inherited Traits
23
Genetic Engineering
24
The Double Helix
25
Traits and Heredity
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National Standards Correlations
Benchmarks for Science Literacy
(Project 2061 - AAAS)
The Living Environment - Heredity (5B) Grades 3-5
By the end of the fifth grade, students should know that:
• Some likenesses between children and parents, such as eye color in human beings,
or fruit or flower color in plants, are inherited. Other likenesses, such as people’s table
manners or carpentry skills, are learned.
• For offspring to resemble their parents, there must be a reliable way to transfer
information from one generation to the next.
National Science Education Standards
(Content Standards: K-4, National Academy of Sciences)
Life Science - Content Standard C:
• Many characteristics of an organism are inherited from the parents of the
organism, but other characteristics result from an individual’s interactions with
the environment. Inherited characteristics include the color of flowers and the
number of limbs of an animal. Other features, such as the ability to ride a bicycle,
are learned through interactions with the environment and cannot be passed on to
the next generation.
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Traits and Heredity
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Student Learning Objectives
Upon viewing the video and completing the enclosed student activities,
students will be able to do the following:
• Define traits as the distinguishing characteristics of an organism.
• Describe heredity as the process of passing on traits from parents to
offspring.
• Differentiate between acquired traits and inherited traits, giving
examples of each.
• Identify Gregor Mendel as the father of modern genetics, and define
genetics as the study of heredity.
• Briefly describe Mendel’s Law of Dominance, explaining that the
stronger trait is called the dominant trait and the weaker trait is the
recessive trait.
• Generally explain that chromosomes are structures in cells that
contain genetic material.
• Define DNA as the chemical that determines the genetic code.
• Understand that genetic engineering is a field of scientific
research that has accomplished many beneficial things. However, also
understand that there is some controversy and concern about the longterm effects of genetic engineering.
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Traits and Heredity
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Assessment
Preliminary Test (p. 14-15):
The Preliminary Test is an assessment tool designed to gain an
understanding of students’ preexisting knowledge. It can also be used as a
benchmark upon which to assess student progress based on the objectives
stated on the previous pages.
Post-Test (p. 16-17):
The Post-Test can be utilized as an assessment tool following student
completion of the program and student activities. The results of the
Post-Test can be compared against the results of the Preliminary Test to
assess student progress.
Video Review (p. 18):
The Video Review can be used as an assessment tool or as a student
activity. There are two sections. The first part contains questions displayed
during the program. The second part consists of a five-question video quiz
to be answered at the end of the video.
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Introducing the Program
Before showing the video program to students, ask students to feel their
earlobes. Also tell them to look closely at the earlobes of some of their
classmates. Explain that there are two different types of earlobes: attached
and unattached. Have students observe a classmate who has attached
earlobes and one who has unattached earlobes. Next ask students if they
can play a musical instrument. Again have them compare the results with
the entire class.
Next tell students that these sorts of distinguishing characteristics can
also be called traits. Write the word “trait” on the board. Ask students if
they can think of any other traits. Make two lists of different traits on the
board, separating inherited and acquired traits. Ask students if they notice
a difference between the two lists. Introduce the concept of acquired traits
which are skills that you learn. Discuss the concept of inherited traits, which
are traits you inherit from your parents. Tell students to pay close attention to
the video to learn more about traits and heredity.
Program Viewing Suggestions
The student master “Video Review” is provided (p. 18) for distribution to
students. You may choose to have your students complete this Master while
viewing the program or do so upon its conclusion.
The program is approximately 14 minutes in length and includes a five-question
video quiz. Answers are not provided to the Video Quiz in the video, but are
included in this guide on page 12. You may choose to grade student quizzes
as an assessment tool or to review the answers in class.
The video is content-rich with numerous vocabulary words. For this reason you
may want to periodically stop the video to review and discuss new terminology
and concepts.
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Traits and Heredity
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Video Script
1.
2.
3.
4.
Has anyone ever told you that you have your mother’s or your father’s eyes?
Or have you ever wondered why the children in a certain family all look so similar?
These similarities not only occur in people but in plants and animals as well.
Perhaps you have looked at flowers in a garden and been amazed at how they all look
very alike.
5. Notice how this calf looks so similar to its mother.
6. What causes these similarities between offspring and parents?
7. Or why in some cases do parents and offspring look different from each other?
8. During the next few minutes we are going to explore these questions as we take a look
at some of the factors involved in passing characteristics from parents to offspring.
9. And we will discuss some of the major scientific discoveries which have given us a
greater understanding of traits and heredity.
10. Graphic Transition – What is Heredity?
11. Things such as the color of your hair,...
12. ...the color of your eyes,...
13. ...the markings on the wings of a butterfly,...
14. ...and the shape of this bird’s beak are all characteristics.
15. Another word for characteristics is traits.
16. We have thousands of different traits.
17. Some of these traits, such as skin color and the shape of our ears are traits we can
easily observe.
18. Other traits, such as the shape of a heart valve, or blood type are more difficult to see.
19. A living thing, whether it be a person,...
20. ...animal, or plant has many different traits.
21. Some traits, such as hair color, are passed on from parents to offspring, while others
such as athletic ability are not.
22. “Heredity” is the process of passing on traits from parents to offspring.
23. Let’s take a minute to compare traits that are passed on and those that are not.
24. Graphic Transition – Acquired and Inherited Traits
25. Think about a skill you had to develop, such as reading...
26. ...playing soccer...
27. ...or playing a musical instrument.
28. You Decide!
Are these skills inherited or learned?
29. That’s right, these skills are learned. You are not born with these traits but over time,
and with practice, you acquired these skills. Things that you learn are called “acquired
traits.”
30. Some traits such as hair color, eye color, or your height are not acquired. You can’t
learn or practice something to make your eyes blue.
31. These types of traits are called inherited traits.
32. “Inherited traits” are characteristics that you are born with.
33. Let’s now take a closer look at inherited traits.
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Video Script
34. Graphic Transition – Inherited Traits
35. Our understanding of the process of heredity is relatively young, and we are learning new
things all the time.
36. It was not until the 1860’s that the field of genetics began to take form.
37. “Genetics” is the study of the process of heredity.
38. In the 1860’s an Austrian monk by the name of Gregor Mendel performed thousands of
experiments that established the foundation of the science of genetics.
39. Working mainly with pea plants in his garden, Mendel studied a number of different traits
such as pea plant height,...
40. ...seed color, seed shape...
41. ...and flower position to name just a few.
42. He became very interested in the way these traits were passed on from parents to offspring
over several generations.
43. Mendel himself was also able to control the appearance of traits in offspring by directly
controlling the breeding process.
44. Over a period of seven years, Gregor Mendel took careful notes on the 20,000 plants that
he grew.
45. From his work, Mendel hypothesized that two factors exist for a given characteristic.
46. For example, in the trait for plant height, one factor for height comes from the father, and
the other factor for height comes from the mother.
47. Today scientists call the factors that control traits genes.
48. “Genes” are the basic units of heredity.
49. Let’s explore how genes can interact with each other.
50. Graphic Transition – Dominant and Recessive Traits
51. One of Mendel’s most important discoveries dealt with the principle of dominance and
recessiveness.
52. He reasoned that in some cases one factor could mask another factor.
53. For example, in the case of pea plant height, the trait of tall height masks, or dominates,
the factor for short plant height.
54. The stronger trait which masks the weaker trait is called the dominant trait.
55. And the weaker trait that seemed to disappear is called the recessive trait.
56. This principle is summarized in the Law of Dominance, which states that in a living thing
the dominant trait is expressed and the recessive trait is hidden.
57. There are many traits in humans which are dominant and recessive including earlobe
formation, hairline appearance,
58. ...and even the ability to roll your tongue.
59. The idea of dominance and recessiveness is just one of the many important discoveries
Gregor Mendel made while working with pea plants in his garden.
60. Graphic Transition – Chromosomes
61. The work of Gregor Mendel went largely unnoticed for over 30 years.
62. But in the early 1900’s scientists rediscovered his work, which serves as the foundation for
the modern science of genetics.
63. Scientists agreed with Mendel’s earlier findings that certain traits are inherited from parents.
64. And they also discovered that genes responsible for traits, are found inside cells on small
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Video Script
structures called chromosomes.
65. “Chromosomes” contain genetic material made up of many, many genes.
66. Every cell in the body contains chromosomes.
67. Today we know that chromosomes, magnified here many hundreds of times, control the
traits of an organism.
68. Graphic Transition – DNA
69. In the 1940’s and 1950’s several scientists including Martha Chase, Alfred Hershey,
Edwin Chargaff, Rosalind Franklin, and Maurice Wilkins...
70. ...as well as James Watson and Francis Crick added to our understanding of genetic
material.
71. They found that the genetic material, which makes up genes, consits of a complex
chemical called deoxyribonucleic acid, or DNA for short.
72. You Observe!
Describe the shape of this DNA molecule.
73. That’s right, the DNA molecule kind of looks like a ladder that has been twisted.
74. Scientists call the shape of the DNA molecule a double helix.
75. A close inspection shows that the rungs on the double helix are formed by pairs of
substances called nitrogen bases The DNA ladder may contain hundreds of millions of
pairs of nitrogen bases.
76. There are four different types of nitrogen bases in DNA. These bases combine in
specific ways.
77. The arrangement of the bases determines the genetic code.
78. Graphic Transition – Genetic Engineering
79. One of the most active fields of scientific investigation involves studying the genetic code
not only of humans, but of all kinds of living things from...
80. ...plants to animals to viruses.
81. Genetic engineering involves the amazing process of actually changing the genetic
makeup of a living thing.
82. For example, scientists have produced vaccines by genetically changing viruses to
protect us from harmful diseases.
83. Genetic engineering has also created crops which are more resistant to disease, and
also produce higher yields.
84. Through genetic engineering, microorganisms have even been altered to process
sewage and even clean up oil spills.
85. While there have been numerous benefits from genetic engineering...
86. ...there is concern about the long-term effects that genetically altered organisms may
have on people and the environment.
87. Graphic Transition – Summing Up
88. During the past few minutes we have briefly explored some of the aspects of traits and
heredity.
89. We began by discussing how traits are characteristics of an organism.
90. We observed that some traits, such as eye color, are inherited traits, while others such
as playing an instrument are acquired traits.
91. Heredity is the study of the passing of traits from parents to offspring.
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Video Script
92. Some of the early work of Gregor Mendel was highlighted,...
93. ...particularly the concept of dominant and recessive traits.
94. We saw that the genetic material is found on chromosomes inside cells.
95. The actual material which makes up the genetic code-DNA was also described.
96. Finally, we discussed some of the benefits and concerns of genetic engineering.
97. So the next time you look in the mirror...
98. ...or spend time with family members...
99. Think about some of the things we have discussed during the past few minutes.
100. You just might think about traits and heredity a little differently.
101. Graphic Transition – Video Assessment
102. Fill in the correct word to complete the sentence. Good luck and let’s get started!
1. _________ are the characteristics of a living thing.
2. Hair color is an example of an __________ trait.
3. ________ is the study of heredity.
4. __________ are made up of many, many genes.
5. ______ is the genetic material found in genes.
Answers can be found on page 12.
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Answer Key to Student Assessments
Pre-Test (p. 14-15)
Post-Test (p. 16-17)
1. c - traits
2. a - heredity
3. d - acquired trait
4. b - inherited trait
5. a - genetics
6. b - pea plants
7. c - dominant
8. d - recessive
9. c - DNA
10. a - genetic engineering
11. true
12. false
13. false
14. true
15. false
16. Heredity is the process of passing on
traits from parents to offspring.
17. An example of an acquired trait is the
ability to play the piano. An example of an
inherited trait is the color of your eyes.
18. Genetics is the study of heredity.
19. When you say a trait is “dominant”, it
means that the stronger trait sometimes
masks the weaker trait.
20. DNA is the complex chemical
compound that makes up genetic material.
1. c - dominant
2. b - inherited trait
3. c - DNA
4. d - recessive
5. d - acquired trait
6. c - traits
7. a - genetics
8. a - genetic engineering
9. a - heredity
10. b - pea plants
11. false
12. false
13. true
14. true
15. false
16. DNA is the complex chemical
compound that makes up genetic material.
17. When you say a trait is “dominant”, it
means that the stronger trait sometimes
masks the weaker trait.
18. Heredity is the process of passing on
traits from parents to offspring.
19. Genetics is the study of heredity.
20. An example of an acquired trait is the
ability to play the piano. An example of an
inherited trait is the color of your eyes.
Video Review (p. 18)
1. The skills, such as reading, playing
soccer, or playing a musical instrument,
are learned skills.
2. The DNA molecule looks like a ladder that has been twisted. The shape is
called a double helix.
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Traits and Heredity
1.
2.
3.
4.
5.
traits
inherited
Genetics
Chromosomes
DNA
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Answer Key to Student Activities
Vocabulary (p. 19 )
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
heredity
acquired
traits
chromosomes
genetic engineering
dominant
inherited
DNA
recessive
genetics
Writing Activity (p. 20)
Characteristics of an organism are called traits. The
process of passing traits from parents to offspring is
known as heredity. Not all traits are passed on by
parents to offspring. Skills that you must practice
to learn are called acquired traits. The study of
heredity is genetics. Gregor Mendel was one of the
first scientists to study genetics. Mendel developed
the Law of Dominance. It states that stronger
traits often mask weaker traits. The weaker traits
are called recessive traits. In the 1950s, scientists
discovered DNA, the chemical that makes up genes.
Genes are responsible for the traits of an organism.
Through the process of genetic engineering
scientists have been able to alter the genetic
makeup of a living thing.
In Your Own Words (p. 20)
1. Heredity is the name for the way that traits are
passed from one generation to the next.
2. An inherited trait is a trait that is passed on from the
parents to offspring. An acquired trait is a trait that is
learned or obtained over time.
3. The role of DNA is to hold the genetic material of
an organism.
Dominant and Recessive Traits
(p. 21-22)
1. In his experiments with pea plants, Gregor Mendel
controlled the breeding of the parents in order to see
exactly how traits were passed from one generation to
the next.
2. Mendel discovered dominant traits and recessive
traits. Dominant traits are the “stronger” traits that
usually mask the “weaker” recessive traits.
3. From his mother, the child inherited curly hair,
unattached earlobes, and dimples.
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Dominant and Recessive Traits cont’d.
4. The offspring inherited a widow’s peak and cleft
chin from his father.
5. Recessive traits that can be seen in the pictures
are straight hair, straight hairline, attached earlobes,
no dimples, and smooth chin.
6. You can assume which traits are recessive
because they are the traits that do not appear in the
offspring.
Acquired vs. Inherited Traits (p. 23)
Height –
Using a computer –
Eyecolor –
Shoe size –
Driving a car –
Skin color –
Reading –
Playing the guitar –
Hitting a baseball –
Blood type –
Shape of your nose –
Speaking French –
Pierced ears –
Freckles –
inherited
acquired
inherited
inherited
acquired
inherited
acquired
acquired
acquired
inherited
inherited
acquired
acquired
inherited
Genetic Engineering (p. 24)
1. Genetic engineering is the process that allows
scientists to change the genetic makeup of a
living thing.
2. A GMO is a genetically modified organism, the
first GMO was created in 1974.
3. Benefits of genetic engineering include
creating foods that are resistant to disease, and
developing medecines. Concerns are that the
environment will become less diverse, and that
the long term effects are completely unknown.
The Double Helix (p.25)
1. The structure of DNA was discovered in 1953 by
James D. Watson and Francis Crick.
2. The double helix looks like a ladder that has been
twisted.
3. There are four different types of nitrogen bases in
DNA. The arrangement of the bases determines the
genetic code.
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Pre-Test
Name
Circle the best answer for each of the following questions.
1. Another word for characteristics of a living thing is:
a. markings
b. flowers
c. traits
d. tasks
2. The process of passing on traits from parents to offspring is called:
a. heredity
b. ability
c. skills
d. reproduction
b. inherited trait
c. hard trait
d. acquired trait
3. A trait that you learn is an:
a. applied trait
4. If you get a trait from your parents, it is referred to as an (a):
a. simple trait
b. inherited trait
c. easy trait
d. acquired trait
c. biology
d. chemistry
5. What is the science of heredity called?
a. genetics
b. paleontology
6. Gergor Mendel worked with this organism in his studies of heredity:
a. mice
b. pea plants
c. rats
d. moss
7. The “stronger” trait which tends to mask a “weaker” trait is called:
a. winning
b. recessive
d. powerful
c. dominant
8. A weak trait that seemingly disappears is referred to as:
a. fading
9.
b. dominant
c. losing
d. recessive
c. DNA
d. acid
What substance determines genetic code?
a. blood
b. marrow
10. The process of altering the genetic make-up of a living thing is:
a. genetic engineering
b. biochemistry
c. physics
d. paleontology
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Pre-Test
Name
Write true or false next to each statement.
11.
Hair color is an example of an inherited trait.
12.
If you practice and study enough, you can make your eyes
blue.
13.
Gregor Mendel bred horses to study genetics.
14.
Chromosomes contain the genetic material found in cells.
15.
Genetic engineering has been unsucessful in changing the
genes of living things.
Write a short answer for each of the following.
16. What is heredity?
17. List one example each of an acquired trait and an inherited trait.
18. What is genetics?
19. What does it mean to say a trait is “dominant”?
20. What is DNA?
Traits and Heredity
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Post-Test
Name
Circle the best answer for each of the following questions.
1. The “stronger” trait which tends to mask a “weaker” trait is called:
a. winning
b. recessive
d. powerful
c. dominant
2. If you get a trait from your parents, it is referred to as an (a):
a. simple trait
3.
b. inherited trait
c. easy trait
d. acquired trait
c. DNA
d. acid
What substance determines genetic code?
a. blood
b. marrow
4. A weak trait that seemingly disappears is referred to as:
a. fading
b. dominant
c. losing
d. recessive
b. inherited trait
c. hard trait
d. acquired trait
5. A trait that you learn is an:
a. applied trait
6. Another word for characteristics of a living thing is:
a. markings
b. flowers
c. traits
d. tasks
c. biology
d. chemistry
7. What is the science of heredity called?
a. genetics
b. paleontology
8. The process of altering the genetic make-up of a living thing is:
a. genetic engineering
b. biochemistry
c. physics
d. paleontology
9. The process of passing on traits from parents to offspring is called:
a. heredity
b. ability
c. skills
d. reproduction
10. Gergor Mendel worked with this organism in his studies of heredity:
a. mice
b. pea plants
c. rats
d. moss
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Post-Test
Name
Write true or false next to each statement.
11.
If you practice and study enough, you can make your eyes
blue.
12.
Genetic engineering has been unsucessful in changing the
genes of living things.
13.
Chromosomes contain the genetic material found in cells.
14.
Hair color is an example of an inherited trait.
15.
Gregor Mendel bred horses to study genetics.
Write a short answer for each of the following.
16. What is DNA?
17. What does it mean to say a trait is “dominant”?
18. What is heredity?
19. What is genetics?
20. List one example each of an acquired trait and an inherited trait.
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Video Review
Name
While you watch the video, answer these questions:
You Decide!
1. Are these skills inherited or learned?
You Observe!
2. Describe the shape of this DNA molecule.
After you watch the video, test your knowledge with these
questions.
1. ___________ are the characteristics of a living thing.
2. Hair color is an example of an _______________ trait.
3. ____________ is the study of heredity.
4. ________________ are made up of many, many genes.
5. __________ is the genetic material found in genes.
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Vocabulary
Name
Use these words to fill in the blanks next to the sentences below.
Words
DNA
genetics
inherited
heredity
dominant
acquired
chromosomes
traits
recessive
genetic engineering
1.
The process of passing traits from parents to
offspring.
2.
Traits that are learned or developed over time.
3.
Another word for characteristics of an organism.
4.
Small structures in cells that contain genetic material.
5.
The process of changing the genetic makeup of an
organism.
6.
The stronger trait that sometimes masks the weaker
characteristic.
7.
Traits that you are born with.
8.
The chemical that makes up genetic material.
9.
The weaker trait that seemingly disappears.
10.
The study of the process of heredity.
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Writing Activity
Words
genetics
DNA
heredity
Name
Dominance
traits
acquired
recessive
engineering
Use the correct word from above to complete the sentences in the following
paragraph.
Characteristics of an organism are called _____________ . The process of
passing traits from parents to offspring is known as ______________ . Not all
traits are passed on by parents to offspring. Skills that you must practice to learn
are called ______________ traits. The study of heredity is _______________ .
Gregor Mendel was one of the first scientists to study genetics. Mendel developed
the Law of ________________ . It states that stronger traits often mask weaker
traits. The weaker traits are called ________________ traits. In the 1950s,
scientists discovered _______ , the chemical that makes up genes. Genes are
responsible for the traits of an organism. Through the process of genetic
________________ scientists have been able to alter the genetic makeup of a
living thing.
In Your Own Words
1. What is heredity?
2. What is an inherited trait? What is an acquired trait?
3. What is the role of DNA?
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Dominant and
Recessive Traits
Name
Background: Gregor Mendel, an Austrian monk, is often credited with beginning the
science of genetics in the 1860s. By controlling the breeding of pea plants, Mendel was
able to see exactly how traits were passed down from one generation to the next. Through
his careful experiments with over 15,000 pea plants Mendel learned a great deal about the
process of heredity.
One of Gregor Mendel’s most important discoveries was the difference between dominant
and recessive traits. Mendel developed a principle called the Law of Dominance. It states
that there are two different forms of a trait. The dominant trait is the “stronger” trait, which is
usually expressed in the offspring. The recessive trait is the “weaker” trait; it is not usually
visible in the offspring. For example, in the case of pea plant height, the trait for tallness
dominates that of shortness. In pea plants, tallness is a dominant trait.
People have dominant and recessive traits as well. For example, feel your earlobes.
Are they attached directly to your head? Or do they hang free? In the case of earlobes,
unattached earlobes are dominant over attached earlobes.
Directions: Look carefully at the pictures of the parents and offspring below. Decide
which traits you think are inherited from the mother and which traits are inherited from the
father. Finally, answer the questions on the next page.
Mother
Father
curly hair
straight hair
straight hairline
widow’s peak
unattached
earlobes
attached
earlobes
dimples
no dimples
smooth chin
cleft chin
curly hair
Offspring
widow’s peak
unattached
earlobes
dimples
cleft chin
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Dominant and
Recessive Traits
Name
Questions:
1. What did Gregor Mendel control in his experiments with pea plants? Why did he do
this?
2. List the two types of traits that Mendel discovered, and describe them.
3. Which traits did the child get from his mother?
4. Which traits did he get from his father?
5. List all of the recessive traits you noticed in the pictures.
6. How did you know which traits were recessive?
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Acquired vs.
Inherited Traits
Name
Background: You probably already know that the characteristics of an organism are
referred to as traits. There are two different kinds of traits, characteristics you are born
with, and those that you learn or obtain over time. Traits that you have from birth are called
inherited traits. For example, the color of your hair is an inherited trait. Those traits that
you must learn or develop during your life, such as playing the violin, are acquired traits. In
this activity you will practice distinguishing between inherited traits and acquired traits.
Directions: For each of the traits listed below, decide whether the trait is acquired or
inherited.
Height
Using a computer
Eyecolor
Shoe size
Driving a car
Skin color
Reading
Playing the guitar
Hitting a baseball
Blood type
Shape of your nose
Speaking French
Pierced ears
Freckles
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Genetic
Engineering
Name
Read the information below, and then answer the questions.
People have controlled the reproduction of some animals and
plants for many years. Today, scientists are using techniques that allow
them to change the genetic makeup of a living thing. This process is
called genetic engineering. It is one of the most active fields of scientific
research today. Using genetic engineering, scientists are able to change
an organism’s genetic code. This means that they can create plants and
animals with desirable traits without breeding. The organisms that result
from genetic engineering are called genetically modified organisms, or
GMOs.
The first GMO was created in 1974. Since then, scientists have
created many different types of genetically modified organisms.
For example, scientists have cloned the genetic code of a sheep. This means that
there are two sheep that have the exact same genetic code. Scientists have also used
genetic engineering to create a type of corn that repels insects. Some people believe that
genetically modified foods will be able to save people who are starving. This would happen
because foods like the corn can grow in harsh conditions and provide more nutrients.
Insulin is a chemical that people with diabetes need. Scientists can produce insulin using
genetic engineering.
However, not everyone believes that genetic engineering is a good thing. Some
people say that it is not a good idea to change the natural makeup of a living thing. Others
argue that GMOs will make the environment less diverse because GMOs are stronger
than natural plants and animals. The long term effects of GMOs are completely unknown.
There are both benefits and concerns about genetic engineering.
Questions:
1. What is genetic engineering?
2. What is a GMO and when was the first one created?
3. What are some benefits of genetic engineering? What are some concerns?
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The Double Helix
Name
Background:
In 1953, two scientists, James D. Watson and
Francis Crick, discovered the structure of DNA.
They found the shape of the DNA molecule to be a
double helix, as pictured to the right. The double
helix looks like a ladder that has been twisted.
Each of the rungs on the ladder is made up of a
pair of nitrogen bases. There are four different
types of nitrogen bases in DNA. The sequence of
these chemicals creates the unique genetic code of
every organism. Today we know that the nitrogen
bases always pair up in the following configuations:
cytosine - guanine, adenine - thymine.
Directions:
Using four colors, color in the double helix at the
right side of this page. Pay close attention to the
pairs of nitrogen bases as you color. Use one color
to signify each of the four types of nitrogen bases.
Then answer the questions below.
Questions:
1. When was the structure of DNA discovered, and
by who?
2. Describe the appearance of a double helix.
3. How many different types of nitrogen bases
are in DNA? What does the arrangement of
these bases determine?
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