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CHAPTER 13 ACTIVE READING WORKSHEETS
GENE TECHNOLOGY
Section 13-3: Genetic Engineering
Read the passage below, which covers topics from your textbook. Answer the
questions that follow.
Many viral diseases, such as influenza, smallpox, and polio, cannot be treated
effectively by existing drugs. Instead, many viral diseases are combated by
prevention, using vaccines. A vaccine is a substance that contains a harmless
version of a virus or a bacterium. Traditionally, vaccines have been made of
disease-causing agents—also called pathogens—that have been treated
(chemically or physically) so that they can no longer cause disease. Vaccines
can also be produced using active pathogens that carry surface proteins that are
the same as or very similar to a more harmful pathogen. When a person
contracts the disease or receives a vaccine, his or her body recognizes the
pathogen’s surface proteins and makes antibodies against the pathogen. In the
future, if the same pathogen enters the body, the body is prepared to combat it
quickly and to prevent or weaken the pathogen’s effects.
On rare occasions a vaccine may cause the disease it is intended to protect
people against. Genetic engineering can be used to produce DNA vaccines,
which may be safer than some traditionally prepared vaccines. The genes for a
disease-causing virus’s surface proteins can be inserted into a harmless virus.
The transplanted genes cause the harmless virus to produce the surface
proteins that alert the body to the presence of the disease-causing virus.
Genetic engineering can also be used to alter the genome of a pathogen so that
it no longer causes a disease. The altered pathogens can then be used as a
vaccine against unaltered forms of the pathogen.
Fill in the blank to complete each sentence.
SKILL: Completing Sentences
One reading skill is the ability to complete an incomplete sentence by
logically determining what will complete the unfinished thought.
1. Three examples of viral diseases are ________________________________ .
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Modern Biology
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Genetic Engineering
Name ______________________________ Class ___________________ Date __________________
2. Many viral diseases are combated by prevention through ________________ .
3. A vaccine is a substance that contains a harmless version of a ____________ .
4. Another name for a disease-causing agent is __________________________ .
5. A pathogen can be chemically or physically treated to eliminate its ability to
____________________________________________________________ .
6. If a pathogen enters the body of a person who has been vaccinated for that
particular virus, the body will recognize the __________________________ .
7. Sometimes, a vaccine causes the disease _____________________________ .
8. One method of producing effective DNA vaccines that are safer than vaccines
that are produced by traditional methods is through ____________________ .
9. Through genetic engineering, genes for a disease-causing virus’s surface
proteins are inserted into a ________________________________________ .
10. Genetic engineering can be used to alter the __________________________ .
11. Pathogens that have been altered so that they no longer cause a disease can be
used as a vaccine against _________________________________________ .
Read the question and write your answer in the space provided.
SKILL: Vocabulary Development
12. What is the meaning of the term prevention in the second sentence of the
passage?
_______________________________________________________________
Circle the letter of the phrase that best completes the statement.
13. A body that recognizes a pathogen’s surface proteins has likely
a. received a vaccination for the disease.
b. had the disease at an earlier time.
c. been altered genetically.
d. Both (a) and (b)
Original content Copyright © by Holt, Rinehart and Winston. Additions and changes to the original content are the responsibility of the instructor.
Modern Biology
56
Genetic Engineering