Download - Biology DNA: The Genetic · PDF filePowerPoint Notes on Chapter 9 ... including certain bacteria. ... The Genetic Material. Holt Biology DNA: The Genetic Material., DNA. 12

Name ____________________________________________________________ Period ______

Biology

DNA: The Genetic Material

Date Assignment Points Earned Possible Points

Chapter 9 Vocabulary 13

Chapter 9 Notes

Chapter 9 Questions

Directed Reading 9-2

DNA Structure Skills

Worksheet

Biology Homework:

DNA/Concept Map

Directed Reading 9-3

Active Reading 9-3

Chapter 9 DNA: The Genetic Material

Vocabulary Use the glossary and don’t shorten the definition. If a page number is listed, use that page to

define the term.

Section 1: Identifying the Genetic Material

1. vaccine -

2. virulent –

3. transformation –

4. bacteriophage –

Section 2: The Structure of DNA

5. double helix –

6. nucleotide –

7. deoxyribose –

8. base-pairing rules –

9. complementary base pair –

Section 3: The Replication of DNA

10. DNA replication –

11. DNA helicase –

12. replication fork –

13. DNA polymerase –

PowerPoint Notes on Chapter 9 - DNA: The Genetic Material Section 1 Identifying the Genetic Material Objectives

Relate Griffith’s conclusions to the observations he made during the transformation experiments.

Summarize the steps involved in Avery’s transformation experiments, and state the results.

Evaluate the results of the Hershey and Chase experiment.

Transformation : Griffith’s Experiments

In 1928, ______________________________, a bacteriologist, was trying to prepare a

____________________ against pneumonia.

A vaccine is a substance that is prepared from _______________ or _______________

disease causing agents, including certain bacteria.

The vaccine is introduced into the body to _________________ the _______________

against future infections by the disease-causing agent.

Griffith discovered that ___________________ bacteria could turn virulent when mixed

with bacteria that cause disease.

A bacteria that is virulent is _____________________________________.

Griffith had discovered what is now called _______________________, a change in

genotype caused when cells take up foreign genetic material.

Griffith’s Discovery of

Transformation

Transformation: Avery’s Experiments

In 1944, a series of experiments showed:

o The activity of the material responsible for transformation is not affected by

_______________-destroying enzymes.

o HOWEVER, the activity IS stopped by a ________ -destroying enzyme.

Thus, almost 100 years after Mendel’s experiments, Oswald Avery and his co-workers

demonstrated that __________ is the material responsible for transformation.

Viral Genes and DNA: DNA’s Role Revealed

In 1952, Alfred Hershey and Martha Chase used the

bacteriophage T2 to prove that ___________ carried

genetic material.

A ___________________, also referred to as a phage, is

a _______________ that infects bacteria.

When phages infect bacterial cells, the phages are able

to ______________________________, which are

released when the bacterial cells rupture.

Hershey and Chase carried out the following

experiment:

o Step 1 T2 phages were labeled

with _______________________.

o Step 2 The phages infect E. coli

bacterial cells.

o Step 3 Bacterial cells were spun to

remove the virus's ____________

coats.

Hershey and Chase concluded that the

_________ of viruses is injected into the

bacterial cells, while most of the _______

__________________ remain outside.

The injected DNA molecules cause the

bacterial cells to produce more ________

_________ and proteins.

This meant that the DNA, rather than

proteins, __________________________

_________________, at least in viruses.

Section 2 The Structure of DNA

Objectives

Describe the three components of a nucleotide.

Develop a model of the structure of a DNA molecule.

Evaluate the contributions of Chargaff, Franklin, and Wilkins in helping Watson and Crick determine the double-helical structure of DNA.

Relate the role of the base-pairing rules to the structure of DNA.

A Winding Staircase

Watson and Crick determined that a DNA molecule is a ____________________ — two

strands twisted around each other, like a winding staircase.

_______________________ are the subunits that make up DNA. Each nucleotide is

made of three parts: a phosphate group, a five-carbon sugar molecule, and a nitrogen-

containing base.

The five-carbon sugar in DNA nucleotides is called ____________________________.

The nitrogen base in a nucleotide can be either a bulky, _________________________,

or a smaller, _______________________________.

Structure of a Nucleotide

Discovering DNA’s Structure:

Chargaff’s Observations

In 1949, Erwin Chargaff observed that for each organism he studied, the amount of

_______________ always equaled the amount of ________________ (A=T).

Likewise, the amount of ______________ always equaled the amount of ____________

(G=C).

However, the amount of adenine and thymine and of guanine and cytosine __________

between different organisms.

Wilkins and Franklin’s Photographs

By analyzing the complex patterns on

_______________________________

photo, scientists can determine the

structure of the molecule.

In 1952, Maurice Wilkins and Rosalind

Franklin developed high-quality _________

diffraction photographs of strands of _____.

These photographs suggested that the DNA

molecule resembled a tightly coiled ____________ and was composed of two or three

chains of ______________________.

Watson and Crick’s DNA Model

In 1953, Watson and Crick built a model of DNA with the configuration of a __________

________________, a “spiral staircase” of two strands of nucleotides twisting around a

central axis.

The double-helical model of DNA takes into account __________________ observations

and the __________________ on Franklin’s X-ray diffraction photographs.

Pairing Between Bases

An _________________ on one strand always pairs with a ______________ on the

opposite strand, and a _______________ on one strand always pairs with a _________

on the opposite strand.

These _________-_____________________________ are supported by Chargaff’s

observations.

The strictness of base-pairing results in two strands that contain ___________________

________________________________.

The diagram of DNA below the helix makes it easier to visualize the base-pairing that

occurs between DNA strands.

*3 Things that determine how DNA base pairs bond:

1. ________________________

2. ________________________

3. ________________________

Section 3 The Replication of DNA Objectives

Summarize the process of DNA replication.

Describe how errors are corrected during DNA replication.

Compare the number of replication forks in prokaryotic and eukaryotic DNA.

Roles of Enzymes in DNA Replication

The complementary structure of DNA is used as a basis to ______________________

_________________________________________________

The process of making a copy of DNA is called _________________________.

DNA replication occurs during the ____________________ phase of the cell cycle,

before a cell divides.

DNA replication occurs in three steps:

o Step 1 ________________________________opens the double helix by breaking

the _____________ bonds that link the complementary nitrogen bases between the

two strands. The areas where the double helix separates are called

_______________________________.

o Step 2 At the replication fork, enzymes known as ___________________________

move along each of the DNA strands. DNA polymerases add __________________

to the exposed nitrogen bases, according to the ________________________ rules.

o Step 3 Two ________ molecules form that are _________________ to the original

DNA molecule.

Checking for Errors

In the course of DNA replication, _________________________ sometimes occur and

the wrong ___________________________ is added to the new strand.

An important feature of DNA _______________________ is that DNA polymerases

have a “____________________________” role.

This proofreading reduces errors in DNA replication to about _______________ error

per 1 billion nucleotides.

The Rate of Replication

Replication does NOT begin at one end of the DNA molecule and end at the other.

The ____________________ DNA molecules found in ________________________

usually have two replication forks that begin at a single point.

The replication forks move away from each other until they meet on the opposite side of

the DNA circle.

In ________________________ cells, each chromosome contains a single, long strand

of DNA.

Each _______________________ chromosome is replicated in about 100 sections that

are 100,000 ___________________________ long, EACH section with its own starting

point.

With multiple replication forks working in concert, an entire human chromosome can be

replicated in about ____________ hours.

Replication Forks Increase the Speed of Replication

Chapter 9 Section 1 Questions

1. What question did Mendel’s experiments answer?

2. What question did Mendel’s experiment create?

3. What was Frederick Griffith trying to find in his experiments?

4. How does a vaccine work?

5. How were the two types of bacteria different in Griffith’s experiments?

Strain #1(S bacteria)-

Strain #2 (R bacteria)--

6. What happened when Griffith injected the mice with S bacteria?

7. What happened when Griffith injected the mice with R bacteria?

8. What happened when Griffith injected the mice with “heated-killed” S bacteria?

9. What happened when Griffith injected the mice with “heated-killed” S bacteria

and live R bacteria?

10. How did Griffith explain what happened in his experiment?

11. What did Oswald Avery discover?

12. What did Hershey and Chase conclude from their experiments?


1. What was the importance of discovering DNA’s structure?

2. What is meant by double helix?

3. Who discovered the structure of the DNA molecule?

4. What are the three parts of the nucleotide?

a.

b.

c.

5. What is the five carbon sugar in DNA called?

6. What parts of the DNA nucleotide remains the same?

7. What part changes in DNA nucleotide?

8. What are the four different nitrogen bases in DNA?

a.

b.

c.

d.

9. What type of bond holds the two strands of the double helix together?

10. How did Erwin Chargaff contribute to Watson and Crick’s discovery?

11. How did Maurice Wilkins and Rosalind contribute to Watson and Crick’s

discovery?

12. What does adenine always pair with?

13. What does guanine always pair with?

14. What does cytosine always pair with?

15. What does thymine always pair with?


1. When does DNA replication occur during the cell cycle?

2. What enzyme opens the DNA’s double helix by breaking the hydrogen bonds?

3. What is the area where the double helix is held apart called?

4. What enzyme adds the new nucleotides to the original DNA strand?

5. What enzyme is responsible for “proof-reading” the new DNA strands?

6. How many replication forks does prokaryotic DNA have?

7. How many replication forks does eukaryotic DNA have?

Copyright © by Holt, Rinehart and Winston. All rights reserved.

Holt Biology 3 DNA: The Genetic Material

Section: The Structure of DNAIn the space provided, write the letter of the description that best matches the

term or phrase.

______ 1. double helix

______ 2. nucleotides

______ 3. deoxyribose

______ 4. DNA

______ 5. hydrogen bond

______ 6. nitrogen base

______ 7. adenine

______ 8. cytosine

In the space provided, explain how the terms in each pair are related to

each other.

9. base-pairing rules, complementary

10. adenine, thymine

11. cytosine, guanine

Name Class Date

Directed ReadingSkills Worksheet

a. a five-carbon sugar

b. type of bond that holds the double

helix together

c. one of three parts of a nucleotide

made of one or two rings of carbon

and nitrogen atoms

d. subunits that make up DNA

e. one of two pyrimidines used as a

nitrogen base in nucleotides

f. one of two purines used as a

nitrogen base in nucleotides

g. abbreviation for deoxyribonucleic

acid

h. two strands of nucleotides twisted

around each other

Chapter 9 Section 2 Pages 194-197



Name Class Date

Directed Reading continued

Read each question, and write your answer in the space provided.

12. What was Chargaff’s observation about the nitrogen bases in DNA?

13. What role did the photographs of Wilkins and Franklin play in the discovery

of the structure of DNA?

14. What did Watson and Crick deduce about the structure of DNA?

Complete the Section Review questions on page 197, #1-6.


Holt Science: Biology 17 Science Skills Worksheets

INTERPRETING DIAGRAMS

Use the figure below to answer questions 1–3.


1. In the space provided, identify the structures labeled A–E.

A. _________________________________________________________________

B. ____________________________________________________________________

C. ____________________________________________________________________

D. ____________________________________________________________________

E. ____________________________________________________________________

2. What do the lines connecting the two strands represent? Why are there three

lines connecting the strands in some instances and only two lines in others?

3. Suppose that a strand of DNA has the base sequence ATT-CCG. What is the

base sequence of the complementary strand?

Name Class Date

DNA StructureSkills Worksheet

B

C

ED

A

Name ________________________________________________ Score ______ Period ______ Biology Homework: DNA 1. Draw a nucleotide and label its three basic parts. 2. Which parts make up the sides of the ladders? Which parts make up the rungs of the ladder? To which part do the rungs of the ladder attach on the sides? 3. What 2 parts do all nucleotides have in common? 4. What part of a nucleotide makes them different? 5. What is the base pair rule? Who discovered this idea? 6. What did Franklin and Wilkins’ x-ray diffraction photograph of strands of DNA suggest about the structure of the DNA molecule? 7. Using Chargaff’s data and the x-ray diffraction photograph of DNA, who built the first model of DNA and describe its structure? 8. What 3 things determine which nitrogen bases pair with which? 9. Which of the 4 nitrogen bases are purines? Which of the 4 nitrogen bases are pyrimidines? 10. Use the base pair rule to complete the missing side of DNA. Pretend the list of nitrogen bases is an entire nucleotide. Match up the correct missing side of this DNA molecule. G G C T C C C T T T G C G C A A A A T G C T A T C G C C G G A A A T T G T C A



Using the terms and phrases provided below, complete the concept map showing

the discovery of DNA structure.

amount of base pairs Franklin and Wilkins pyrimidine

DNA polymerases nitrogen base replication

double helix phosphate group Watson and Crick

five-carbon sugar purine

Name Class Date

Concept MappingSkills Worksheet

Discovery of DNA structure

includes research by

X-ray photosof DNA

who showed who showedwho showed

Chargaff

nucleotides

which undergoeswhich is composed of

which involvesmade of a

which can be a

such as

1. 2.

3. 4.

5. 6.

7.

8.

9. 10. 11.



Section: The Replication of DNAIn the space provided, write the letter of the description that best matches the

term or phrase.

______ 1. DNA replication

______ 2. DNA helicases

______ 3. replication forks

______ 4. DNA polymerases

______ 5. synthesis


6. How did the complementary relationship between the sequences of

nucleotides lead to the discovery of DNA replication?

7. What prevents the separated DNA strands from reattaching to one another

during DNA replication?

8. What prevents the wrong nucleotide from being added to the new strand

during DNA replication?

Complete each statement by writing the correct term or phrase in the space

provided.

9. Prokaryotic DNA is reproduced with replication

forks.

Name Class Date

Directed ReadingSkills Worksheet

a. add nucleotides to the exposed nitrogen

bases according to the base-pairing rules

b. process of making a copy of DNA

c. the two areas that result when the double

helix separates during DNA replication

d. open up the double helix by breaking the

hydrogen bonds between nitrogen bases

e. phase during the life cycle of a cell during

which DNA replication occurs




Name Class Date

Directed Reading continued

10. Each human chromosome is replicated in about

sections.

11. The number of nucleotides between each replication fork in human DNA is

approximately .

Complete Section Review questions on page 200, # 1-5 below.



Section: The Replication of DNARead the passage below. Then answer the questions that follow.

The process of making a copy of DNA is called DNA replication.

It occurs during the synthesis (S) phase of the cell cycle, before a

cell divides. The process can be broken down into three steps.

Step 1: Before replication can begin, the double helix must

unwind. This is accomplished by enzymes called DNA helicases,

which open up the double helix by breaking the hydrogen bonds

that link the complimentary nitrogen bases. Once the two strands

of DNA are separated, additional enzymes and other proteins

attach to each strand, holding them apart and preventing them

from twisting back into their double-helical shape. The two areas

on either end of the DNA where the double helix separates are

called replication forks because of their Y shape.

Step 2: At the replication fork, enzymes known as DNA

polymerases move along each of the DNA strands, adding

nucleotides to the exposed nitrogen bases according to the

base-pairing rules. As the DNA polymerases move along, two

new double helixes are formed.

Step 3: Once a DNA polymerase has begun adding nucleotides

to a growing double helix, the enzyme remains attached until

all of the DNA has been copied and it is signaled to detach. This

process produces two DNA molecules, each composed of a new

and an original strand. The nucleotide sequences in both of these

DNA molecules are identical to each other and to the original

DNA molecule.

SKILL: READING EFFECTIVELY


1. What is replication?

2. When does replication occur?

Name Class Date

Active ReadingSkills Worksheet




Name Class Date

Active Reading continued

3. What must occur before replication can begin?

SKILL: INTERPRETING GRAPHICS

4. The figure below shows DNA replicating. In the space provided, describe

what is occurring at each lettered section of the figure.

Part a. _________________________________________________________________

Part b. _________________________________________________________________

Part c. _________________________________________________________________

In the space provided, write the letter of the term or phrase that best completes

the statement.

______ 5. DNA helicases and DNA polymerases are alike in that both are

types of

a. nucleotides.

b. nitrogen bases.

c. enzymes.

d. Both (a) and (b)

Part a. Part b. Part c.

Download - Biology DNA: The Genetic · PDF filePowerPoint Notes on Chapter 9 ... including certain bacteria. ... The Genetic Material. Holt Biology DNA: The Genetic Material., DNA. 12

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