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Name
12
Class
DNA
Date
Chapter Test B
Multiple Choice
Write the letter that best answers the question or completes the statement on the line provided.
_____ 1. In Griffith’s bacterial transformation experiments.
a. harmless bacteria change into harmful bacteria.
b. harmful bacteria change into harmless bacteria.
c. harmless bacteria are infected by viruses.
d. harmful bacteria are infected by viruses.
_____ 2. What happened when Griffith injected mice with the harmless, R-strain bacteria alone?
a. The bacteria transformed.
c. The mouse died.
b. The mouse lived.
d. The bacteria died.
_____ 3. What did Griffith observe when he injected a mixture of heat-killed, disease-causing bacteria
and live harmless bacteria into mice?
a. The disease-causing bacteria dies.
b. The mice developed pneumonia.
c. The harmless bacteria died.
d. The mice were unaffected.
_____ 4. What did Avery conclude caused transformation?
a. DNA was the transforming factor.
b. A protein was the transforming factor.
c. A carbohydrate was the transforming factor.
d. A lipid was the transforming factor.
_____ 5. What is inside a bacteriophage?
a. protein.
b. nucleic acid.
c. lipid
d. carbohydrate
_____ 6. What do bacteriophages infect?
a. mice.
b. humans.
c. viruses.
d. bacteria.
_____ 7. What happens when a piece of DNA is missing?
a. Genetic information is stored.
b. Genetic information is copied.
c. Genetic information is lost.
d. Genetic information is transmitted.
_____ 8. In what way is DNA like a book?
a. DNA has information organized with an kind of index.
b. DNA has stored information, that can be copied and passed on.
c. DNA has information wrapped in an identifying cover.
d. DNA has information that is periodically updated.
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_____ 9. Which of the following could make up one nucleotide found in DNA?
a. adenine + phosphate group + thymine
b. cytosine + phosphate group + guanine
c. deoxyribose + phosphate group + polymerase
d. deoxyribose + phosphate group + cytosine
_____ 10. Because of base pairing in DNA, the percentage of
a. adenine in DNA is about equal to the percentage of guanine.
b. thymine in DNA is about equal to the percentage of adenine.
c. adenine in DNA is much greater than the percentage of thymine.
d. cytosine in DNA is much greater than the percentage of guanine.
Percentages of Bases in Five Organisms
Source of DNA
A
Human
Chicken
28.8
Bacterium (S. lutea)
13.4
T
G
19.9
29.4
C
21.5
Figure 12–1
_____ 11. Figure 12–1 shows the results of measuring the percentages of the four bases in the DNA of
three organisms. Some of the values are missing. Based on Chargaff’s rule, the percentages
of guanine bases in chicken DNA should be around
a. 28.8%
c. 21.5%
b. 19.9%
d. 13.4%
_____ 12. Avery’s experiment worked because bacteriophages and bacteria share which component?
a. proteins
c. DNA
b. carbohydrates
d. lipids
_____ 13. What did Rosalind Franklin contribute to the effort to identify the structure of DNA?
a. models made of cardboard and wire showing the shape of DNA
b. the ratios of the two sets of nucleotide pairs in DNA
c. radioactive evidence that DNA carried the genetic code
d. x-ray diffraction photos of the DNA molecule
_____ 14. During DNA replication, a DNA strand that has the bases CTAGGT produces a strand with
the bases
a. TCGAAC.
c. AGCTTG.
b. GATCCA.
d. GAUCCA.
_____ 15. In eukaryotes, DNA
a. is located in the nucleus.
c. is located in the ribosomes.
b. floats freely in the cytoplasm. d. is circular.
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Modified True/False
Indicate whether the statement is true or false. If false, change the underlined word or phrase to make
the statement true.
_____16. A bacteriophage is larger than a bacterium.
_____17. The three parts of a DNA nucleotide are the phosphate group, deoxyribose, and the base.
_________________
_____18. In eukaryotes, DNA replication proceeds in one direction along the DNA molecule.
Completion
Complete each statement on the line provided.
19. The outer covering of the virus in Figure 12–2 is made of
.
20. The structure labeled X in Figure 12–3 is a(n)
.
21. The Watson and Crick model of DNA is a(n)
which two strands are wound around each other.
, in
Figure 12–2
22. ___________________ are weak bonds that hold the two strands of
DNA together, but also allow the DNA to separate and replicate.
23. DNA replication is carried out by a series of
.
24. The tips of chromosomes are known as
.
Short Answer
In complete sentences, write the answers to the questions on the lines
provided.
25. During DNA replication, what two processes must occur before the
two strands of a DNA molecule can separate?
Figure 12–3
26. Identify and explain the role of the molecule, represented by the spheres in
Figure 12–4.
27. Identify one difference between prokaryotic and eukaryotic DNA replication.
Figure 12–4
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Answer Key
Chapter 12 —Test B
Multiple Choice
1. a 2. b 3. b 4. a 5. b 6. d 7. c 8. b 9. d 10. b 11. c 12. c 13. d 14. b 15. d
Modified True/False
16. F; smaller 17. T 18. F; two directions
Completion
19. protein coat 20. nucleotide 21. double helix 22. Hydrogen bonds 23. enzymes 24. telomeres
Short Answer
25. The hydrogen bonds between the base pairs must be broken, and the molecule must unwind.
26. The molecule is DNA polymerase, an enzyme that joins individual nucleotides to make a strand of DNA.
27. In prokaryotes, DNA replication starts in one place, and in eukaryotes DNA replication starts in many
places.