Practice Worksheet for SBQ1-AK[1].pdf

Practice Sheet SBQ1 BIO40A-G9ASP
1
Subtopic 5.5 Identifying the Substance of the Gene
1.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
changed into harmless bacteria
√ B. The mice developed pneumonia
C. The harmless bacteria died
D. The mice were unaffected
2. Which of the following is true about the figure given?
A. It revealed every detail about the structure of DNA
√ B. X-ray photograph of DNA produced by Franklin
C. It was used to study RNA
D. X-ray photograph of DNA produced by Watson and Crick
3. Which of the following is true about Griffith’s experiment?
A. He concluded that DNA is the genetic material
B. When heat-killed, S-strain bacterial cause the mouse to die
√ C. R-strain bacteria became disease causing when mixed with heat-killed S-strain bacteria
D. S-strain bacteria can cause disease only when heat-killed

2
4. Use the figure below that represents part of the experiment that was conducted by
Griffith to answer questions a and b.
a. Describe the experimental set up and the results of each set in Griffiths experiment.
Set
up
Result
Set-1 Griffith infected mice with the virulent bacteria (strain S) the mice died
Set-2 Griffith infected mice with the non-virulent bacteria (strain R) the mice
survived
Set-3 Griffith infected mice with heat-killed virulent bacteria (strain S) the mice died
Set-4 Griffith infected mice with a mix of heat-killed strain S and
living strain R
the mice died
b. What was the conclusion in set 4? What did this conclusion indicate?
Griffith’s concluded that the living R cells had somehow been transformed into
virulent S cells
It indicated that there was some form of transferrable genetic material present
within the cells

3
5. Use the table below, which summarizes Griffith experiments, to answer questions a-d.
a. Identify one control experiment among the four experiments shown in the table.
Explain your answer.
- Experiment 1. The use of the living S type bacteria to infect the mouse/all
variables kept the same.
- Experiment 2. The use of living R type bacteria to infect the mouse/all variables
kept the same.
b. Complete the table below to explain the results of each experiment.
Experiment Explanation of the results
1
The live S type is virulent that caused the death of the mouse/the immune
system of the mouse could not kill the bacteria
2
The live R type is a non-virulent and the mouse was not affected by it/the
immune system of the mouse was able to kill the bacteria
3 The dead S type did not affect the mouse/ unable to cause disease/death
4
The live R type has changed into avirulent type when mixed with the dead S
type and caused the mouse to die
c. Describe one conclusion that Griffith drawn from the experiment.
- There is a substance/chemical in the heat-killed S type that has transformed the
R type to become a virulent type.
d. Suggest what the next experimental step might be after Griffith experiment.
- To identify the substance that caused the transformation of the bacteria.

4
6. Use the diagram below, which shows the steps of the two experiments of Hershey and Chase,
to answer questions a-c
a. Evaluate the choice of using sulfur and phosphorus as radioactive labelling agents in
this experiment.
Sulfur is found in proteins but not DNA and phosphorus is found in DNA but not proteins.
It will be easy to track these two chemicals during the course of the experiment.
b. Based on the bar graph below, determent the bar that represents the sulfur
radioactive part of the experiment and the bar that represents the phosphorus
radioactive part of the experiment.
A: Sulfur radioactive
B: Phosphorus radioactive
c. A student claims that if the virus that was used in the
experiment is an RNA virus that can successfully infect
bacteria, then the results will be different. Identify whether this claim is correct or not
and support your answer with scientific explanation.
II. The claim is incorrect.
III. RNA is a nucleic acid and is made of the same elements as DNA. It
contains phosphorus but not sulfur, and thus the results of the experiment will be the
same.

5
5.6 The Structure of DNA
1.Structure X represents a , while structure Y represents a .
A. sugar molecule phosphate group
B. nitrogenous base hydrogen bond
√ C. phosphate group sugar molecule
D. phosphate group hydrogen bond
2.If the percentage of Adenine in the DNA is 28% then the percentage of Guanine will be .
√ A. 22%
B. 28%
C. 48%
D. 57%
3. Which of the followings does NOT apply to the nucleotide base-pairing rule?
A. √Adenine pairs with Guanine
B. Pyrimidine pairs with Purine
C. Thymine pairs with Adenine
D. Guanine pairs with Cytosine

6
4. Among the molecules represented below, which of them are purines?
A. 1 and 5 only
B. 1 and 3 only
C. All of them are purines
D. 3, 4 and 5 only
√ E. 1 and 2 only
5. Which of the following is/are NOT component(s) in the DNA nucleotide?
II. Ribose
III. Deoxyribose
IV. Thymine
V. IV. Uracil
A. I and II only
B. I and III only
C. II and III only
D. √ I and IV only
6. Chargaff discovered that the base Thymine is almost equal in percentage to__________.
√ A. adenine
B. cytosine
C. guanine
D. uracil
7. Which base pairs are found in DNA_________.
A. A–C and T–G
√ B. A–T and C–G
C. A–G and C–T
D. A-U and C-G
1 2 3 4 5

7
8. Refer to the following figure that shows part of a DNA molecule to answer questions a and b.
a. Identify the structures labeled Q, W
and Z in the figure.
Structure Q: nucleotide
Structure W: phosphate group
Structure Z: deoxyribose sugar
b. Name the three molecules indicated
as 1, 2 and 3 in the figure.
1: Guanine
2: Thymine
3: Cytosine or Guanine
9. Complete the blanks with suitable term or words.
Statement Term
The basic unit of the DNA molecule Nucleotide
Adenine always bind with Thymine
Bonding between the nitrogenous bases in the DNA Hydrogen
A type of virus that infects bacteria Bacteriophage
Single ringed nitrogenous bases Pyrimidines
Double ringed nitrogenous bases Purine
Adenine and Guanine Purine
Thymine, cytosine and uracil Pyrimidines
10. What type of bond connects base pairs_________.
A. covalent bond
B. ionic bond
√ C. hydrogen bond
D. peptide bond

8
11. Watson and crick breakthrough model of DNA by announcing that it is a_________.
A. single helix
√ B. double Helix
C. triple Helix
D. nonhelical
12. Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism.
Approximately what percentage of the nucleotides in this sample will be thymine?
A. 8%
√ B. 16%
C. 42%
D. 58%
E. 48%
13. A sample of DNA was analyzed to have 45% of nitrogenous bases with two fused carbon rings
that have the ability to form two hydrogen bonds. These nitrogenous bases are most
probably_______________ bases
√ A. adenine
B. cytosine
C. guanine
D. thymine
E. uracil
14. Refer to the following figure that shows part of a
DNA molecule to answer questions a-b.
a. Identify the structures labeled A, B, C and D in the
figure.
Structure A: deoxyribose sugar
Structure B: phosphate group
Structure C: nitrogenous base
Structure D: nucleotide
b. Name different forms of structure C.
Adenine, Guanine, Cytosine, Thymine

9
5.7DNA Replication
1. Which of the following is/are the correct DNA replication process(es) in humans?
A Replication A
B Replication B
√ C. Replication C
D Replication A and C
2. Which of the following best describes the DNA Replication process?
A. It is dispersive because each new DNA molecule has one parent strand and one daughter strand
B. It is reductive, because each new strand has half of the original DNA
√ C. It is semi conservative, because each new DNA has one original strand and one new strand
D. It is fully conservative, because the new copies are exactly the same like the original molecule
3. Use a √ to identify which statements are true about DNA replication in
both eukaryotes and prokaryotes.
Statement Prokaryot
e
Eukaryot
e
Bot
h
Origin of replication is needed to start the replication process √
Replication occurs in both directions √
Replication occurs along a circular DNA molecule √
Replication occurs along a linear DNA molecule √
Has multiple origins of replication √
Has one origin of replication √

10
4. Use the table to identify the enzymes in Figures 1 and 2 and their function in the process of
DNA replication.
Figure 1 Figure 2
Enzyme
Fig. 1
Enzyme
Name
Function Enzyme
Number in Fig.
2
A Helicase It unwinds and separates the DNA into single
strands to prepare for replication
2
B DNA
Polymerase
It adds new nucleotides to the growing
nucleotide chain
6
C Ligase It connects DNA fragments of the lagging
strand
8
5. At the beginning of the process of DNA replication the strands___________.
A. Bind
B. Copy
C. Attach
√ D. Separate

11
6. Place the steps of DNA replication in the correct order.
3, 4, 1, 2
7. Identify the types of cells based on the DNA replication processes shown in Figures A
and B.
Figure A: Prokaryotes
Figure B: Eukaryotes

12
8. DNA replication results in two DNA molecules__________________.
A. each with two new strands.
B. one with two new strands and the other with two original strands.
√ C. each with one new strand and one original strand.
D. each with two original strands.
9. During DNA replication, a DNA strand that has the bases CTAGGT produces a strand with
the bases____.
A. TCGAAC.
√ B. GATCCA.
C. AGCTTG.
D. GAUCCA.
10. In the figure below, what nucleotide is going to be added at point 1, opposite from
thymine?
A. Guanine
B. Thymine
√ C. Adenine
D. Cytosine
11. In both prokaryotes and eukaryotes, how many copies of the chromosome are left after
replication?
A. 1
√ B. 2
C. 3
D. 4

13
12. Which events take place in DNA replication?
I. Formation of messenger RNA
II. Unwinding of DNA double helix
III. Formation of complementary strands by DNA polymerase
A. I and II only
B. I and III only
√ C. II and III only
D. I, II and III
13. The main enzyme involved in DNA replication is____________.
A. DNA oxidase
B. DNA synthase
√ C. DNA polymerase
D. DNA ligase
14. Which of the following are pyrimidines______________.
A. Adenine - Guanine
B. Guanine – Cytosine
C. Adenine – Cytosine
√ D. Thymine - Cytosine
15. The molecule labeled X in the adjacent diagram is the_____________.
A. RNA polymerase
B. DNA helicase
C. DNA ligase
D. DNA topoisomerase
√ E. DNA polymerase

14
16. Which of the following statements is TRUE in regard to the figure below?
I. It takes place in the cytoplasm
II. Many origins are formed
III. Occurs in two opposing directions at the same time
A. I only
B. II only
√ C. I and II
D. II and III
17. Complete the following chart that summarizes DNA replication. First step is mentioned
to guide you.
The enzyme Helicase unzips the DNA
molecule and the two strands unwind.
Unwound DNA serves as
templates for new DNA
DNA polymerase joins individual
nucleotides to produce new strand
DNA polymerase prof read the newly
formed strands
DNA ligase zips the nucleotides together

15
18. Diagram I below shows the pairing between two nitrogenous bases in a DNA molecule.
Diagram II shows the process of DNA replication. Use the two diagrams answer
questions a-c.
a. Identify the type of the nitrogenous bases X and Y in diagram I. Explain your answer.
- X: Purine/Guanine. It is composed of two fused rings and pairs to the other
nitrogenous base by three hydrogen bonds.
- Y: Pyrimidine/Cytosine. It is composed of one ring and pairs to the other
nitrogenous base by three hydrogen bonds.
b. Identify whether diagram II illustrates DNA replication in a prokaryotic or eukaryotic
cell. Explain your answer.
- Prokaryotic cell.
- One origins of replication/circular DNA.
c. Identify whether the labeled sequence W in diagram II is formed as a leading strand
or a lagging strand. Explain your answer.
- Leading strand.
- Synthesis is with the direction of replication/replication fork.

16
19. Use the diagram below, which shows the process of DNA replication, to answer
questions a and b.
a. Describe the role of the two labeled enzymes: X and Y in the diagram.
X: topoisomerase enzyme works in removing the supercoiling that is resulted from
unwinding of DNA during the process of DNA replication.
Y: helicase enzyme is responsible for breaking down hydrogen bonds between the two DNA
strands/unwinds the DNA.
b. Compare and contrast how strand 1 and strand 2 are being built during DNA
replication.
Strand 2 (the leading strand) is the strand which is synthesized in the same direction as the
replication fork while strand 1 (the lagging strand) is the strand which is synthesized in
opposite direction to the replication fork.
Strand 2 (the leading strand) is synthesized continuously while strand 1 (the lagging strand)
is synthesized in fragments which are called Okazaki fragments.
20. Use numbers to sequence the steps of DNA replication.
Sequence Stages of DNA replication
______3______ DNA polymerase builds the leading strand continuously in the 5’à 3’ direction
______5______ Two DNA molecules identical to each other and to the original molecule are
formed
______1______ Helicase unwinds the double helix
______4______ Lagging strand is synthesized discontinuously by building Okazaki fragments
______2______ Single strand binding proteins stabilize the unwound DNA strands

17
21. The diagram below shows a simplified representation of the process of DNA replication.
A, B and C are enzymes involved in the process.
a. Use the table below to identify enzymes A, B, and C. Describe the role of each in
replication.
Letter Name of enzyme Role in DNA replication
Enzyme A Helicase Unwinds DNA strands to allow replication
Enzyme B DNA polymerase Builds DNA molecules by assembling nucleotides
Enzyme C Ligase It connects Okazaki fragments at lagging strand
b. Explain the consequences if enzyme A fails to perform its function.
DNA replication will not occur because without the helicase enzyme the DNA strand cannot
unzip, therefore DNA polymerase cannot bind to the 3' end of the dna and create a new
complimentary strand of DNA.

Practice Worksheet for SBQ1-AK[1].pdf

Empfohlen

Empfohlen

Weitere ähnliche Inhalte

Ähnlich wie Practice Worksheet for SBQ1-AK[1].pdf

Ähnlich wie Practice Worksheet for SBQ1-AK[1].pdf (20)

Kürzlich hochgeladen

Kürzlich hochgeladen (20)

Practice Worksheet for SBQ1-AK[1].pdf