- What is a plasmid? a) A type of bacteria
b) A small, circular piece of DNA
c) A type of virus
d) A protein molecule
Answer: b) A small, circular piece of DNA - Which of the following is a common feature of plasmids used in genetic engineering? a) They are linear in shape
b) They can replicate independently
c) They require a host chromosome to replicate
d) They contain no genes
Answer: b) They can replicate independently - What is the primary use of plasmids in genetic engineering? a) To deliver genetic material into host cells
b) To serve as viruses
c) To convert bacteria into human cells
d) To produce enzymes
Answer: a) To deliver genetic material into host cells - Which of the following is NOT a type of plasmid commonly used in genetic engineering? a) Expression plasmids
b) Cloning plasmids
c) Plant cell plasmids
d) Vector plasmids
Answer: c) Plant cell plasmids - What is a key feature of a plasmid used as a vector in genetic engineering? a) Ability to resist antibiotics
b) Ability to carry foreign genes
c) Ability to undergo mutation
d) Ability to infect human cells
Answer: b) Ability to carry foreign genes - Which enzyme is often used to cut plasmid DNA in genetic engineering? a) DNA polymerase
b) Reverse transcriptase
c) Restriction enzymes
d) Ligase
Answer: c) Restriction enzymes - What is the function of a selectable marker gene in a plasmid? a) To help the plasmid replicate
b) To allow for the selection of successfully transformed cells
c) To enhance plasmid uptake by host cells
d) To silence unwanted genes
Answer: b) To allow for the selection of successfully transformed cells - What is the typical size range for plasmids used in genetic engineering? a) 100-500 base pairs
b) 1,000-10,000 base pairs
c) 50,000-100,000 base pairs
d) 1,000-10,000 kilobase pairs
Answer: b) 1,000-10,000 base pairs - Which process is used to introduce plasmids into bacterial cells? a) Photosynthesis
b) Electroporation
c) Meiosis
d) Mutation
Answer: b) Electroporation - What role do plasmids play in bacterial antibiotic resistance? a) They block antibiotic entry into cells
b) They produce antibiotics
c) They carry genes that confer antibiotic resistance
d) They help bacteria avoid mutation
Answer: c) They carry genes that confer antibiotic resistance - Which of the following is a feature of the plasmid pBR322? a) It contains an antibiotic resistance gene
b) It is used exclusively in plant genetic engineering
c) It contains genes for human protein production
d) It is a virus
Answer: a) It contains an antibiotic resistance gene - How can plasmids be used to produce insulin in genetic engineering? a) By inserting the gene for insulin production into the plasmid and transferring it to bacteria
b) By modifying the plasmid to create a new hormone
c) By extracting the insulin from plant cells
d) By inserting a human cell nucleus into the plasmid
Answer: a) By inserting the gene for insulin production into the plasmid and transferring it to bacteria - What is the role of ligase in plasmid-based genetic engineering? a) To cut DNA into fragments
b) To seal the plasmid and foreign DNA together
c) To help plasmids replicate
d) To transport the plasmid into the cell
Answer: b) To seal the plasmid and foreign DNA together - Which of the following plasmid vectors is commonly used in plant genetic engineering? a) Ti plasmid
b) pBR322 plasmid
c) Lambda phage
d) Adenovirus
Answer: a) Ti plasmid - What type of cells can plasmids be introduced into for genetic engineering? a) Only bacterial cells
b) Only plant cells
c) Only animal cells
d) Both bacterial and eukaryotic cells
Answer: d) Both bacterial and eukaryotic cells - Which process is involved in integrating plasmid DNA into a host cell’s genome? a) Transcription
b) Translation
c) Transformation
d) Replication
Answer: c) Transformation - What is a major advantage of using plasmids in genetic engineering? a) They are naturally resistant to mutation
b) They can be easily manipulated and transferred between organisms
c) They can survive in extreme environments
d) They can be used to clone animals
Answer: b) They can be easily manipulated and transferred between organisms - What is the origin of replication in a plasmid? a) A segment of DNA that initiates replication
b) A gene that promotes plasmid uptake
c) A protein that facilitates foreign gene expression
d) A viral sequence
Answer: a) A segment of DNA that initiates replication - Which of the following is an example of a plasmid used in cloning? a) pBR322
b) Green fluorescent protein (GFP) plasmid
c) Adenoviral plasmid
d) Retroviral plasmid
Answer: a) pBR322 - How can scientists confirm successful transformation of a cell with plasmid DNA? a) By analyzing the plasmid’s size
b) By checking the presence of a selectable marker
c) By counting the number of bacteria
d) By isolating the foreign DNA
Answer: b) By checking the presence of a selectable marker - What is the purpose of antibiotic resistance genes in plasmids used for genetic engineering? a) To ensure that the plasmid DNA does not degrade
b) To allow transformed cells to survive in the presence of antibiotics
c) To prevent plasmid replication in the host cell
d) To enhance the plasmid’s ability to infect other organisms
Answer: b) To allow transformed cells to survive in the presence of antibiotics - Which of the following is NOT a common use of plasmids in genetic engineering? a) Gene therapy
b) Protein production
c) Gene cloning
d) Photosynthesis enhancement
Answer: d) Photosynthesis enhancement - What is the term for the process in which a plasmid is inserted into a bacterial cell? a) Conjugation
b) Transduction
c) Transformation
d) Replication
Answer: c) Transformation - What is the main purpose of inserting a foreign gene into a plasmid? a) To kill the host cell
b) To replicate the plasmid inside the host cell
c) To produce the protein encoded by the foreign gene
d) To increase the plasmid’s size
Answer: c) To produce the protein encoded by the foreign gene - Which of the following is a major benefit of using plasmids for gene cloning in research? a) They can carry very large genes
b) They can replicate without the need for a host cell
c) They are easy to manipulate and transfer between organisms
d) They can store energy for the cell
Answer: c) They are easy to manipulate and transfer between organisms - What is one limitation of using plasmids for gene expression in eukaryotic cells? a) Eukaryotic cells cannot accept plasmids
b) Plasmids cannot replicate inside eukaryotic cells
c) Eukaryotic cells do not contain antibiotic resistance genes
d) Plasmids may not efficiently express genes in eukaryotic cells
Answer: d) Plasmids may not efficiently express genes in eukaryotic cells - Which of the following molecules is typically used to insert plasmid DNA into host cells? a) RNA polymerase
b) Reverse transcriptase
c) Calcium chloride
d) RNA
Answer: c) Calcium chloride - Which type of plasmid is used in the genetic engineering of plants? a) Ti plasmid
b) F plasmid
c) R plasmid
d) Col plasmid
Answer: a) Ti plasmid - What does the process of plasmid cloning aim to do? a) Modify the genetic sequence of an organism
b) Produce genetically identical organisms
c) Clone a single gene of interest for study or application
d) Isolate plasmids from bacterial cells
Answer: c) Clone a single gene of interest for study or application - Which of the following is the primary method used to select transformed cells in genetic engineering? a) Electroporation
b) Antibiotic resistance
c) Gene silencing
d) PCR amplification
Answer: b) Antibiotic resistance
These MCQs cover a broad range of knowledge on plasmids’ roles in genetic engineering.
