MICR 290 Exam Compilations Questions And
Complete Solutions, Guaranteed Passing| Latest
Update | 2025/2026
1. What are the correct features of a plasmid? - ANSWER ✓
Circular, double-stranded DNA present in the bacterial
cytoplasm
Many plasmids carry genes that confer antibiotic resistance
2. Why are plasmids useful? - ANSWER ✓ Plasmids are
extremely valuable tools for biotechnology applications, and
recombinant plasmids are used in many different areas of
research. By inserting a sequence of DNA into a plasmid and
transforming a bacterial culture with this recombinant DNA, the
culture can then be used as a "factory" to produce a massive
number of copies of the plasmid. This is one way to produce
copies of the DNA sequence that was inserted into the plasmid
(i.e. the insert). The resulting plasmid can then be purified from
the bacterial culture (e.g. using spin columns) and used in down-
stream applications.
,3. What are vectors? - ANSWER ✓ The plasmids used in the
lab for cloning purposes are known as vectors, as they act as
"vectors" for the insert that they carry.
Many of the plasmids used for research purposes are artificial
constructs, combining DNA sequences from several different
sources (including natural bacterial plasmids).
Most empty vectors are relatively small, typically ranging from
2-5 kb (kilobases) in size; this contrasts natural plasmids, which
are often 10-100 kb. Cloning vectors can be considered to be
"stripped down" versions of natural plasmids, consisting
principally of the core components required for plasmid
replication and selection. As long as these components are not
disrupted, it is possible to clone almost any insert DNA
sequence into a plasmid.
4. What is cloning? - ANSWER ✓ Cloning refers to the process
of inserting a sequence of DNA (also called an insert) into a
plasmid. The resulting plasmid is a form of recombinant DNA,
meaning that it is an artificial (i.e. laboratory-produced)
construct combining DNA sequences from two or more different
sources.
,It refers to the process of inserting a sequence of DNA into a
vector. The insert may come from various sources (e.g. from
DNA purified from bacteria), but is most commonly produced
by polymerase chain reaction.
Plasmids used for cloning are known as cloning vectors, and are
designed to simplify the process of transferring an insert into the
empty vector. If the goal is to produce a protein encoded by the
insert DNA (i.e. the insert is a gene), a specific kind of cloning
vector known as an expression vector must be used.
5. What are the 3 components found in most cloning vectors? -
ANSWER ✓ 1. Multiple Cloning Site (MCS):
This region of DNA is designed to simplify the process of
cloning an insert into the vector. This region is recognized by
several different restriction enzymes, enzymes which cut DNA.
The insert can then be enzymatically connected to the cut vector.
2. Origin of Replication (Ori):
This sequence of DNA is required for the plasmid to be
replicated by bacteria. This sequence is recognized by the
bacterial replication machinery (i.e. enzymes that replicate
DNA), which produce more copies of the plasmid. The origin of
replication plays a role in determining the copy number of a
plasmid, which determines the number of copies of the plasmid
in a cell.
, 3. Selectable Marker:
This is a gene that makes it possible to selectively culture the
bacteria that contain the plasmid. Selectable markers tend to be
genes that confer antibiotic resistance. Therefore, in the presence
of the antibiotic, bacteria transformed with the plasmid will
survive and bacteria which lack the plasmid will die.
6. How can we clone insert DNA into a vector? - ANSWER ✓
A common approach using restriction enzymes and an enzyme
known as DNA ligase.
In this process, the empty vector is cut open using restriction
enzymes, and the insert is connected to the cut vector by DNA
ligase.
7. What are restriction enzymes? - ANSWER ✓ Restriction
enzymes, or restriction endonucleases, are enzymes that cleave
phosphodiester linkages, breaking the bond between the
phosphorus atom of the phosphate group and the oxygen of the
deoxyribose sugar. This effectively cuts a strand of DNA into
two smaller strands.
*Very selective: only cleave DNA at these sites
Complete Solutions, Guaranteed Passing| Latest
Update | 2025/2026
1. What are the correct features of a plasmid? - ANSWER ✓
Circular, double-stranded DNA present in the bacterial
cytoplasm
Many plasmids carry genes that confer antibiotic resistance
2. Why are plasmids useful? - ANSWER ✓ Plasmids are
extremely valuable tools for biotechnology applications, and
recombinant plasmids are used in many different areas of
research. By inserting a sequence of DNA into a plasmid and
transforming a bacterial culture with this recombinant DNA, the
culture can then be used as a "factory" to produce a massive
number of copies of the plasmid. This is one way to produce
copies of the DNA sequence that was inserted into the plasmid
(i.e. the insert). The resulting plasmid can then be purified from
the bacterial culture (e.g. using spin columns) and used in down-
stream applications.
,3. What are vectors? - ANSWER ✓ The plasmids used in the
lab for cloning purposes are known as vectors, as they act as
"vectors" for the insert that they carry.
Many of the plasmids used for research purposes are artificial
constructs, combining DNA sequences from several different
sources (including natural bacterial plasmids).
Most empty vectors are relatively small, typically ranging from
2-5 kb (kilobases) in size; this contrasts natural plasmids, which
are often 10-100 kb. Cloning vectors can be considered to be
"stripped down" versions of natural plasmids, consisting
principally of the core components required for plasmid
replication and selection. As long as these components are not
disrupted, it is possible to clone almost any insert DNA
sequence into a plasmid.
4. What is cloning? - ANSWER ✓ Cloning refers to the process
of inserting a sequence of DNA (also called an insert) into a
plasmid. The resulting plasmid is a form of recombinant DNA,
meaning that it is an artificial (i.e. laboratory-produced)
construct combining DNA sequences from two or more different
sources.
,It refers to the process of inserting a sequence of DNA into a
vector. The insert may come from various sources (e.g. from
DNA purified from bacteria), but is most commonly produced
by polymerase chain reaction.
Plasmids used for cloning are known as cloning vectors, and are
designed to simplify the process of transferring an insert into the
empty vector. If the goal is to produce a protein encoded by the
insert DNA (i.e. the insert is a gene), a specific kind of cloning
vector known as an expression vector must be used.
5. What are the 3 components found in most cloning vectors? -
ANSWER ✓ 1. Multiple Cloning Site (MCS):
This region of DNA is designed to simplify the process of
cloning an insert into the vector. This region is recognized by
several different restriction enzymes, enzymes which cut DNA.
The insert can then be enzymatically connected to the cut vector.
2. Origin of Replication (Ori):
This sequence of DNA is required for the plasmid to be
replicated by bacteria. This sequence is recognized by the
bacterial replication machinery (i.e. enzymes that replicate
DNA), which produce more copies of the plasmid. The origin of
replication plays a role in determining the copy number of a
plasmid, which determines the number of copies of the plasmid
in a cell.
, 3. Selectable Marker:
This is a gene that makes it possible to selectively culture the
bacteria that contain the plasmid. Selectable markers tend to be
genes that confer antibiotic resistance. Therefore, in the presence
of the antibiotic, bacteria transformed with the plasmid will
survive and bacteria which lack the plasmid will die.
6. How can we clone insert DNA into a vector? - ANSWER ✓
A common approach using restriction enzymes and an enzyme
known as DNA ligase.
In this process, the empty vector is cut open using restriction
enzymes, and the insert is connected to the cut vector by DNA
ligase.
7. What are restriction enzymes? - ANSWER ✓ Restriction
enzymes, or restriction endonucleases, are enzymes that cleave
phosphodiester linkages, breaking the bond between the
phosphorus atom of the phosphate group and the oxygen of the
deoxyribose sugar. This effectively cuts a strand of DNA into
two smaller strands.
*Very selective: only cleave DNA at these sites
