Molecular Biology Practice Questions - Set B





1.         The bond between a phosphate group and the ribose sugar group in RNA is called which of the following?

a.         Phosphodiester linkage

b.         Glycosidic bond

c.         Peptide bond

d.         Hydrogen bond

e.         Amide bond


2.         The bond between complementary bases in DNA are called which of the following?

a.         Phosphodiester linkages

b.         Glycosidic bonds

c.         Peptide bonds

d.         Hydrogen bonds

e.         Amide bonds


3.         Which of the following is does not play a role in DNA replication?

a.         DNA polymerase

b.         Helicase

c.         Okazaki fragments

d.         DNA Ligase

e.         Guanyl transferase


4.         Which of the following codons would not have a corresponding tRNA?

a.         UAA

b.         CGA

c.         UUU

d.         AUG

e.         GCG


5.         Which of the following is the most likely rate of translation in prokaryotic organisms (a unit = one monomer in the growing chain or polymer)?

a.         2 units per second

b.         11 units per second

c.         156 units per second

d.         1187 units per second

e.         5692 units per second


6.         Codons that code for the same amino acid are called:

a.         Synonyms or synonymous

b.         Similar or alike

c.         Degenerate or redundant

d.         Complements or complementary

e.         Synchronous


7.         Adenine and guanine are examples of what class of nitrogen base?

a.         Glycols

b.         Pyrimidines

c.         Glycosides

d.         Purines

e.         Steroids


8.         What signals the end of transcription?

a.         Stop codon

b.         Terminator

c.         The end of the DNA chain

d.         RNA polymerase runs out

e.         End codon


9.         The start codon in mRNA is:

a.         AUU

b.         UAA

c.         AUG

d.         UAG

e.         ATC


10.       Which of the following is not a component of a nucleotide?

a.         Phosphate group

b.         Anti-codon

c.         Nitrogen base

d.         Ribose

e.         Deoxyribose


11.       What is the typical rate of mutation per round of DNA replication?

a.         1 in 1,000 base pairs

b.         1 in 10,000 base pairs

c.         1 in 1,000,000 base pairs

d.         1 in 1,000,000,000 base pairs


12.       Which of the following is an example of a missense mutation?

a.         UAC to UAG

b.         AAA to UAA

c.         UGC to UCC

d.         UAA to UGA

e.         UUU to CCC


13.       The structure of tRNA resembles a(n):

a.         Cloverleaf

b.         an "L" shape

c.         A helix

d.         a double helix

e.         a cube

14.       Which of the following is not a DNA base?

a.         Thymine

b.         Uracil

c.         Adenine

d.         Guanine

e.         Cytosine


15.       What is the name of the enzyme responsible for helping charge tRNA molecules?

a.         Guanyl transferase

b.         Polymerase

c.         Helicase

d.         Aminoacyl-tRNA synthase

e.         Ligase


16.       Which of the following is not an RNA base?

a.         Adenine

b.         Uracil

c.         Thymine

d.         Cytosine

e.         Guanine


17.       The strand on which DNA replication is continuous is called the:

a.         Leading strand

b.         Lagging strand

c.         Major strand

d.         Minor strand

e.         Dominant strand


18.       What is the name of a mutation that changes the reading frame of an RNA molecule?

a.         Frameshift mutation

b.         Missense mutation

c.         Nonsense mutation

d.         Change-frame mutation

e.         A base pair substitution


19.       What is the enzyme responsible for stitching together Okazaki fragments?

a.         Helicase

b.         Single-stranded binding protein

e.         Primase

d.         Ligase

e.         Nuclease


20.       How many base pairs make up a codon?

a.         1

b.         2

c.         3

d.         4

e.         8


21.       If a codon consisted of 4 bases, how many different codons would be possible?

a.         0

b.         20

c.         64

d.         256

e.         1024


22.       How many hydrogen bonds are formed between one A:T base pair?

a.         1

b.         2

c.         3

d.         4

e.         5


23.       What is the name of the enzyme responsible for unwinding helical DNA for replication?

a.         Helicase

b.         DNA Polymerase

c.         Ligase

d.         Exonuclease

e.         RNA Polymerase


24.       How many nucleotides specify an amino acid?

a.         1

b.         3

c.         6

d.         9

e.         12


25.       What links codons and anti-codons together during DNA translation?

a.         DNA ligase

b.         Single-stranded binding protein

c.         Complementary base pairing

d.         GTP

e.         Amino acid acyl synthase


26.       Which of the following is not a source of DNA damage?

a.         Chemical damage

b.         Splicing

c.         Attack by water

d.         Radiation damage

e.         Transposable element


27.       At which position on the ribose ring is the base group attached to the nitrogen base group?

a.         1'

b.         2'

c.         3'

d.         4'

e.         5"


28.       At which position on the ribose ring is does DNA polymerase add a nucleotide in the process of DNA synthesis?

a.         1'

b.         2'

c.         3'

d.         4'

e.         5"










1.         A

2.         D

3.         E

4.         A

5.         B

6.         C

7.         D

8.         B

9.         C

10.       B

11.       C

12.       C

13.       A

14.       B

15.       D

16.       C

17.       A

18.       A

19.       D

20.       C

21.       D

22.       B

23.       A

24.       B

25.       C

26.       C

27.       A

28.       C