Lesson 3 | DNA and Genetics
Student Labs and Activities
Page
Appropriate For:
Launch Lab
46
all students
Content Vocabulary ELL
47
all students
Lesson Outline ELL
48
all students
MiniLab
50
all students
Content Practice A
51
AL
AL
AL
Content Practice B
52
AL
OL
BL
School to Home
53
Key Concept Builders
54
Enrichment
58
Challenge
59
AL
AL
BL
Lab A
62
AL
AL
AL
Lab B
65
AL
OL
BL
Lab C
68
AL
AL
BL
Chapter Key Concepts Builder
69
AL
AL
AL
Lesson Quiz A
60
AL
AL
AL
Lesson Quiz B
61
AL
OL
BL
Chapter Test A
70
AL
AL
AL
Chapter Test B
73
AL
OL
AL
Chapter Test C
76
AL
AL
BL
all students
AL
AL
AL
all students
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Assessment
Teacher Support
Answers (with Lesson Outlines)
AL Approaching Level
T6
OL On Level
BL Beyond Level
ELL English-Language Learner
Teacher evaluation will determine which activities to use or modify to meet any ELL student’s proficiency level.
Genetics
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Name
Date
Class
Launch Lab
LESSON 3: 20 minutes
How are codes used to determine traits?
Interpret this code to learn more about how an organism’s body cells use codes to
determine genetic traits.
Procedure
1. Analyze the pattern of the simple
A
code shown to the right. For example,
= DOG
2. In your Science Journal, record the
correct letters for the symbols in the
code below.
D
B
E
C
F
G
H
I
J
K
L
M
N
Q
O
P
R
U
S
V
T
W
X
Y
Z
1. What do all codes, such as Morse code and Braille, have in common?
2. What do you think might happen if there is a mistake in the code?
3.
Key Concept How do you think an organism’s cells might use code to determine
its traits?
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Genetics
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Think About This
Name
Date
Class
Content Vocabulary
LESSON 3
DNA and Genetics
Directions: Write the correct term in the boxes to the right of each definition. Then unscramble the letters
in the shaded boxes to spell a seventh term.
DNA
mutation
nucleotide
RNA
transcription
translation
replication
1. a change in the nucleotide
sequence of a gene
2. the copying of DNA
3. carries the code for
making proteins from the
nucleus to the cytoplasm
4. process that makes mRNA
from DNA
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
5. nitrogen base + a sugar +
a phosphate group
6. organism’s genetic
material
7. When they are unscrambled, the letters from the shaded boxes spell
, the process that uses RNA to make protein.
Genetics
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Name
Date
Class
Lesson Outline
LESSON 3
DNA and Genetics
A. The Structure of DNA
1. Genes provide
for a cell to assemble molecules that
express traits such as eye color or seed shape.
2. Chromosomes are made of proteins and deoxyribonucleic acid, or
, which is an organism’s genetic material.
3. Strands of DNA in a chromosome are tightly
like a
telephone cord.
4. The work of several scientists revealed that DNA is shaped like a twisted ladder,
or a(n)
.
5. DNA is made of
, which are molecules made of a
nitrogen base, a sugar, and a phosphate group.
6. There are four
bases—adenine (A), cytosine (C),
thymine (T), and guanine (G).
7.
copies a DNA molecule to make another DNA
molecule. It produces two
strands of DNA.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
B. Making Proteins
1. The DNA of each cell carries a complete set of genes that provides instructions
for making all the
a cell requires.
2. Segments of DNA that are not parts of genes are often called
DNA.
3. Ribonucleic acid, or
, is a type of nucleic acid that
carries the code for making proteins from the nucleus to the cytoplasm.
a. Like DNA, RNA is made of
.
b. Unlike DNA, RNA is single-stranded and has the sugar
. It has the nitrogenous base
instead of thymine.
4. The process of making mRNA from DNA is
.
5. The three types of RNA are transfer RNA, ribosomal RNA, and
RNA.
6. The process of making a protein from RNA is called
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.
Genetics
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Date
Class
Lesson Outline continued
7. The order of the nitrogen bases in mRNA determines the order of the
in a protein.
8. Each series of three nitrogen bases on mRNA is called
a(n)
.
a. Most codons code for
.
b. One of the codons codes for an amino acid that is at the
of a protein. This codon signals that
should start. Three of the codons do not code for
any
. Instead, they code for the
of the protein.
C. Mutations
1. A change in the nucleotide sequence of a gene is a(n)
.
2. Mutations can be triggered by exposure to X-rays,
light,
radioactive materials, and some kinds of chemicals.
3. Types of DNA mutations include deletion mutations,
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
mutations, and substitution mutations.
4. Each type of mutation changes the sequence of nitrogen base pairs, which can
cause a gene to code for a different
than a normal gene.
5. Because mutations can change proteins, they can
change
6. Mutations can have
.
effects, positive effects, or no effect
on traits.
Genetics
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Name
Date
MiniLab
Class
LESSON 3: 25 minutes
How can you model DNA?
Making a model of DNA can help you understand its structure.
Procedure
1. Read and complete a lab safety form.
2. Link a small paper clip to a large
paper clip. Repeat four more times,
making a chain of 10 paper clips.
3. Choose four colors of chenille
stems. Each color represents one of
the four nitrogen bases. Record the
color of each nitrogen base in your
Science Journal.
4. Attach a chenille stem to each large
5. Repeat step 2 and step 4, but this time
attach the corresponding chenille-stem
nitrogen bases. Connect the nitrogen
bases.
6. Securely insert one end of your double
chain into a block of styrene foam.
7. Repeat step 6 with the other end of
your chain.
8. Gently turn the blocks to form a
double helix.
paper clip.
Analyze and Conclude
1. Explain which part of a DNA molecule is represented by each material you used.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
2. Predict what might happen if a mistake were made in creating a nucleotide.
3.
Key Concept How did making a model of DNA help you understand
its structure?
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Genetics
Name
Date
Class
Content Practice A
LESSON 3
DNA and Genetics
Directions: On each line, write the term from the word bank that correctly completes each sentence. Each term
is used only once.
amino acids
DNA
double helix
genes
genetic disorder
mutation
nitrogen
nucleotides
phosphate
proteins
replication
RNA
traits
transcription
translation
1. Chromosomes are made of
and
.
2. An organism’s
are encoded in segments of its
chromosomes called
.
3. A DNA molecule is shaped like a twisted ladder, a shape that is called
a(n)
.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4. The genetic units called
are made of a sugar, a(n)
group, and a(n)
base.
5. The process by which a new copy of a DNA molecule is created is
called
.
6. Three kinds of
molecules carry out genetic instructions for
the production of proteins.
7. This process involves two main steps, called
and
.
8. In the second of those steps, units called
are linked
together.
9. A change in a gene’s sequence of nucleotides is called a(n)
.
10. A change in a gene’s sequence of nucleotides can lead to a(n)
, such as cystic fibrosis.
Genetics
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Name
Date
Content Practice B
Class
LESSON 3
DNA and Genetics
Directions: Answer each question on the lines provided.
1. Which two substances are chromosomes made of?
2. What are the three parts of a nucleotide?
3. What is name for the process by which new copies of DNA are made?
4. What are the three kinds of RNA?
5. What is the process by which the coded DNA information for making a protein
is copied into RNA?
7. What is a mutation, and what are the three types of mutations discussed in the lesson?
8. Which three genetic disorders are caused by mutations?
9. How can a mutation be beneficial?
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Genetics
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6. What process is carried out by RNA to produce a protein?
Name
Date
School to Home
Class
LESSON 3
DNA and Genetics
Directions: Use your textbook to answer each question or respond to each statement.
1. Chromosomes contain the genetic code that controls inherited traits.
Describe the typical set of human chromosomes in each cell in terms of the number
of chromosomes and explain what each parent contributes to each set.
2. The strands of DNA in chromosomes are shaped like a twisted ladder.
DNA’s shape is due to the nucleotides that form it.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
What is a nucleotide, and how does it determine the structure of DNA?
3. The copying of a DNA molecule to make another DNA molecule is called
replication.
What are the steps of replication?
4. Mutation occurs when there is a change in the nucleotide sequence in a gene.
Describe the different types of mutations.
Genetics
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Name
Date
Class
Key Concept Builder
LESSON 3
DNA and Genetics
Key Concept What is DNA?
Directions: On the line before each statement, write T if the statement is true or F if the statement is false.
1. Genetic information is encoded in a molecule called DNA.
2. This molecule is shaped like a twisted ladder, a shape that is called a triple
helix.
3. James Watson and Francis Crick discovered the structure of this molecule after
studying gamma-ray images of the molecule.
4. The sides of the ladder are made from joined molecules called bases.
5. The combination of a nitrogen base, a sugar, and a phosphate group is a unit
called a gene.
6. The base guanine always joins with the base cytosine.
8. The process by which the molecule of heredity makes copies of itself is called
transcription.
9. Most genes encode information for the production of proteins.
Directions: Answer the question on the lines provided.
10. How does DNA replicate itself?
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Genetics
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7. An organism’s genes are located in cell structures called chromosomes.
Name
Date
Class
Key Concept Builder
LESSON 3
DNA and Genetics
Key Concept What is the role of RNA in protein production?
Directions: Complete this concept map by choosing terms from the word bank and writing them in the correct spaces.
amino acids
DNA
instructions
molecules
nucleic acid
proteins
RNA
transcription
translation
units
1.
is a type of
2.
constructs these
7.
that copies coded
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3.
from
8.
from
4.
called
9.
for the production of
5.
in a process called
10.
in a process called
6.
Genetics
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Name
Date
Class
Key Concept Builder
LESSON 3
DNA and Genetics
Key Concept What is the role of RNA in protein production?
Directions: The diagram below shows one strand of a DNA molecule with six bases shown. A strand of mRNA
has just been created from those bases that will be used to make part of a protein. Write the letters of the
corresponding RNA bases on each line provided. (Remember that in RNA, U takes the place of T.)
DNA
A
G
G
C
T
A
mRNA
1.
2.
Directions: Answer each question on the lines provided.
3. Which structures in the cell are proteins assembled in?
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4. What component of a cell are these structures attached to?
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Genetics
Name
Date
Key Concept Builder
Class
LESSON 3
DNA and Genetics
Key Concept How do changes in the sequence of DNA affect traits?
Directions: Answer each question on the lines provided.
1. How many human chromosomes are there?
2. Approximately how many human genes are there?
3. What is a mutation?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
4. Which four causes of mutations are discussed in the lesson?
5. Which two genetic disorders are caused by mutations that are mentioned in the lesson?
Genetics
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Name
Date
Class
Enrichment
LESSON 3
The Sickle-Cell Mutation
In the 1940s, doctors in Africa began to
notice that many patients who survived
malaria had a common mutation—their
hemoglobin was genetically different from
those who got the disease. This genetic
change gave the patients’ red blood cells
a sickle shape, rather than a normal disk
shape. The change was also associated with
a high risk of contracting a potentially fatal
blood disease called sickle-cell disease. In
essence, the sickle-cell mutation protected
the patient from malaria, but gave the
patient another deadly disease.
disease. But he or she does not have the
disease. In the Punnett square shown here,
normal hemoglobin has the dominant
allele S, and the sickle-cell mutation has
the recessive allele s. If both parents are
heterozygous for the sickle-cell mutation,
there is a 25 percent chance that their
offspring will have sickle-cell disease.
S
s
SS
Ss
Ss
ss
S
Natural Selection
Sickle-Cell Genotype
A person who is heterozygous for the
sickle-cell mutation is a carrier of the
s
Treatment
Sickle-shaped red blood cells cannot
easily pass through blood vessels. The result
is intense pain, fever, infections, and
weakness. Currently, no widespread cure
for sickle-cell disease exists, although some
patients have benefited from bone-marrow
transplants. Doctors usually give patients
an arsenal of different treatments to
combat the disease, such as blood
transfusions, antibiotics, and drugs that
help the red blood cells obtain oxygen.
Applying Critical-Thinking Skills
Directions: Answer each question or respond to each statement.
1. Classify the offspring of the heterozygous parents in the Punnett square as normal
hemoglobin, carrier, or sickle cell.
2. Predict What might happen to the sickle-cell mutation if malaria in Africa were
eliminated?
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Genetics
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Scientists estimate that in some areas of
Africa, up to 40 percent of the population
carries at least one sickle-cell gene. Those
people who carry two sickle cell genes, one
from each parent, have sickle-cell disease.
The mutation is most common in those
parts of the continent that are hit hardest
by malaria—the tropical and subtropical
lowlands. The malaria pathogen does not
thrive in sickle-shaped red blood cells. So
people with the sickle-cell mutation tend
to survive, reproduce, and pass on the gene
to future generations.
Name
Date
Challenge
Class
LESSON 3
Mutations
A mutation is a change in the nucleotide sequence of a gene. The diagram below shows
a sequence of DNA. In the space, sketch three possible mutations of the DNA sequence.
Write a brief caption under each drawing. In the captions, identify and describe the
mutation.
T
A
G
C
C
G
T
A
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DNA sequence
Genetics
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