Biotechnology & Applications
What is the role of a selectable marker gene in cloning vectors?
A
To increase the size of the plasmid
B
To identify and select cells that have taken up the recombinant plasmid
C
To prevent bacterial contamination
D
To enhance protein expression
Correct Answer:
B. To identify and select cells that have taken up the recombinant plasmid
Selectable marker genes (like antibiotic resistance genes) allow researchers to identify and select only those cells that have successfully incorporated the recombinant plasmid.
In India, which genetically modified crop has been most widely adopted for commercial cultivation?
A
Bt Brinjal
B
Bt Cotton
C
GM Mustard
D
Herbicide-tolerant soybean
Correct Answer:
B. Bt Cotton
Bt Cotton is the most extensively cultivated GM crop in India since its introduction in 2002, covering millions of hectares across multiple states.
What is the advantage of using CRISPR-Cas9 over traditional gene therapy?
A
It is more expensive
B
It is faster, more precise, and more efficient
C
It only works in prokaryotes
D
It cannot edit genes
Correct Answer:
B. It is faster, more precise, and more efficient
CRISPR-Cas9 is faster, cheaper, and more precise than traditional gene editing methods like zinc finger nucleases or TALENs.
Which technique is used to identify and isolate specific clones from a genomic library?
A
Southern blotting
B
DNA sequencing
C
Gel electrophoresis
D
Northern blotting
Correct Answer:
A. Southern blotting
Southern blotting uses labeled probes to identify specific DNA sequences in clones, allowing isolation of desired clones from genomic libraries.
Golden Rice is enriched with which micronutrient?
A
Iron
B
Iodine
C
Beta-carotene (Vitamin A precursor)
D
Calcium
Correct Answer:
C. Beta-carotene (Vitamin A precursor)
Golden Rice is genetically modified to produce beta-carotene (provitamin A), addressing vitamin A deficiency in developing countries.
In recombinant DNA technology, what is the function of DNA ligase?
A
To cut DNA at specific sites
B
To join DNA fragments by forming phosphodiester bonds
C
To denature double-stranded DNA
D
To synthesize new DNA strands
Correct Answer:
B. To join DNA fragments by forming phosphodiester bonds
DNA ligase catalyzes the formation of phosphodiester bonds between adjacent nucleotides, joining DNA fragments together during cloning.
What does PCR stand for?
A
Polymerase Chain Reaction
B
Protein Coding Region
C
Plasmid Cloning Replication
D
Primary Cell Recognition
Correct Answer:
A. Polymerase Chain Reaction
PCR (Polymerase Chain Reaction) is a molecular technique for amplifying specific DNA sequences through repeated cycles of denaturation, annealing, and extension.
Which of the following is a transgenic organism?
A
Bt cotton
B
Hybrid wheat
C
Polyploid watermelon
D
Mutant rice produced by irradiation
Correct Answer:
A. Bt cotton
Bt cotton contains foreign genes from Bacillus thuringiensis, making it a true transgenic organism. Others are produced by conventional breeding or mutation.
What is the primary purpose of using plasmids in biotechnology?
A
To store genetic information in prokaryotes
B
As vectors for introducing foreign genes into host cells
C
To produce antibodies in animals
D
To facilitate photosynthesis
Correct Answer:
B. As vectors for introducing foreign genes into host cells
Plasmids are small, circular DNA molecules used as vectors to carry and transfer foreign genes into host cells during genetic engineering.
Which enzyme is used to cut DNA at specific recognition sequences in genetic engineering?
A
Restriction endonuclease
B
DNA ligase
C
DNA polymerase
D
Helicase
Correct Answer:
A. Restriction endonuclease
Restriction endonucleases recognize and cut DNA at specific palindromic sequences, producing sticky or blunt ends used in cloning.
