Match the Bioreactor components/systems in List-I with their functions/goals in List-II:
List-I (Bioreactor Component)
List-II (Function/Purpose)
A. Stirrer/Agitator System
I. Maintenance of sterile (microbial contamination-free) ambiance
B. Sampling Ports
II. Facilitates even mixing and oxygen availability throughout the vessel
C. Bioprocess Engineering
III. Allows small volumes of the culture to be withdrawn periodically
D. Continuous Culture System
IV. Produces larger biomass by maintaining cells in active log phase
The stirrer facilitates even mixing and oxygen availability. Sampling ports allow culture withdrawal. Bioprocess engineering maintains sterile ambiance. Continuous culture maintains the log/exponential phase, leading to higher yields.
Question 352 of 535
📘 CLASS XII
Match the methods of introducing alien DNA into host cells (List-I) with their defining characteristic (List-II):
List-I (Method)
List-II (Target/Description)
A. Competent Cells (Heat Shock)
I. Recombinant DNA directly injected into nucleus of animal cell
B. Micro-injection
II. Cells are bombarded with micro-particles coated with DNA (e.g., Gold/Tungsten)
C. Biolistics (Gene Gun)
III. Uses treatment with divalent cation like calcium and brief exposure to 42°C
D. Disarmed Pathogen Vectors
IV. Modified Retroviruses or Ti plasmids used for gene delivery
Competent cells are prepared using divalent cations and heat shock (42°C). Micro-injection involves direct injection into the nucleus of an animal cell. Biolistics uses high velocity micro-particles of gold or tungsten coated with DNA. Disarmed pathogen vectors (like retroviruses or Ti plasmid) transfer recombinant DNA by infection.
Question 353 of 535
📘 CLASS XII
Match the year in List-I with the significant event in the development of RDT/Biotechnology in List-II:
List-I (Year)
List-II (Event)
A. 1963
I. Isolation and characterization of the first sequence-specific restriction endonuclease (Hind II)
B. 1968
II. Stanley Cohen and Herbert Boyer accomplish the construction of the first recombinant DNA molecule
C. 1972
III. Isolation of the two enzymes (one cut DNA, one methylated DNA) restricting bacteriophage growth in E. coli
D. 1936
IV. Herbert Boyer was born
1963: Two enzymes, including restriction endonuclease, isolated from E. coli. 1968: Hind II, the first sequence-specific restriction endonuclease, characterized (five years later than 1963). 1972: Cohen and Boyer constructed the first recombinant DNA molecule. 1936: Herbert Boyer was born.
Question 354 of 535
📘 CLASS XII
Match the pathogen or related element in List-I with its role in natural or engineered gene transfer in List-II:
List-I (Pathogen/Element)
List-II (Associated Vector/Disease)
A. Retroviruses
I. Insect vector for malarial parasite
B. Agrobacterium tumifaciens
III. Source of modified Ti plasmid cloning vector for plants
C. Mosquito
I. Insect vector for malarial parasite
D. T-DNA
IV. Piece of DNA delivered by bacterium to cause tumor formation in plants
Retroviruses are disarmed and used to deliver desirable genes into animal cells. *A. tumifaciens* harbors the Ti plasmid, modified as a plant vector. Mosquito acts as an insect vector to transfer the malarial parasite. T-DNA is the DNA piece delivered by *A. tumifaciens* to transform plant cells.
Question 355 of 535
📘 CLASS XII
Match the steps involved in Downstream Processing (List-I) with their corresponding description/requirement (List-II):
List-I (Downstream Step)
List-II (Component/Requirement)
A. Separation and Purification
I. Thorough testing required for drugs
B. Formulation
II. Collectively referred to as Downstream Processing
C. Clinical Trials
III. Strict testing required for each product
D. Quality Control Testing
IV. Product mixed with suitable preservatives
Separation and purification are collectively referred to as downstream processing. Formulation involves the product being mixed with suitable preservatives. Clinical trials are required for drug formulations. Strict quality control testing is required for each product.
Question 356 of 535
📘 CLASS XII
Match the restriction enzyme characteristics in List-I with their description or quantification in List-II:
List-I (Characteristic)
List-II (Feature/Number)
A. Palindromic Sequence
I. DNA cut at specific positions within the double helix
B. Restriction Endonuclease Function
II. Over 900
C. Number of Restriction Enzymes Known
III. Sequence of base pairs that reads same on the two strands (5' → 3' direction)
D. Recognition Sequence for Hind II
IV. Specific sequence of six base pairs
Palindromic sequence reads the same on both strands in the 5' → 3' direction. Endonucleases make cuts at specific positions within the DNA. More than 900 restriction enzymes are known today. Hind II recognizes a specific sequence of six base pairs.
Question 357 of 535
📘 CLASS XII
Match the individuals/groups in List-I with their key contributions in List-II:
List-I (Scientist)
List-II (Contribution)
A. Herbert Boyer
I. Studied small ringlets of DNA called plasmids
B. Stanley Cohen
II. French philosopher who influenced anthropocentric approach
C. Rene Descartes
III. Observed restriction enzymes leaving 'sticky ends' on DNA
D. Combined work (1972)
IV. Construction of the first artificial recombinant DNA molecule
Boyer observed restriction enzymes leaving sticky ends. Cohen studied plasmids. Descartes influenced the anthropocentric approach. Cohen and Boyer constructed the first recombinant DNA molecule in 1972.
Question 358 of 535
📘 CLASS XII
Match the DNA type in List-I with its replication characteristic in List-II, regarding cloning vectors:
List-I (DNA Type)
List-II (Replication/Copy Number)
A. Plasmid DNA
I. Replicate independent of chromosomal DNA
B. Bacteriophage DNA
II. Low copy number (e.g., one or two copies per cell)
C. Some Plasmids
III. Very high copy numbers of their genome
D. High Copy Number Vector
IV. Used when one wants to recover many copies of target DNA
Plasmids replicate independent of chromosomal DNA. Bacteriophages have very high copy numbers. Some plasmids have only one or two copies per cell. A high copy number vector is chosen to recover many copies of the target DNA.
Question 359 of 535
📘 CLASS XII
Match the component/step of Polymerase Chain Reaction (PCR) in List-I with its description in List-II:
List-I (PCR Requirement)
List-II (Step/Function)
A. Primers
I. Achieves amplification to approximately billion times
B. DNA Polymerase
II. Small chemically synthesised oligonucleotides complementary to DNA regions
C. Repeated Amplification
III. Enzyme used for extension of primers using genomic DNA as template
D. High Temperature Step
IV. Induces denaturation of double stranded DNA
Primers are oligonucleotides complementary to DNA regions. DNA polymerase extends the primers. Repeated amplification results in approximately 1 billion copies. High temperature induces denaturation.
Question 360 of 535
📘 CLASS XII
Match the selection mechanism/result in List-I with the corresponding outcome or requirement in List-II:
List-I (Selection Mechanism)
List-II (Outcome/Feature)
A. Insertional Inactivation
I. Colonies appear blue
B. Non-recombinant Colonies (chromogenic)
II. Colonies do not produce any colour (white)
C. Recombinant Colonies (chromogenic)
III. Requires simultaneous plating on two plates having different antibiotics
D. Selection using two antibiotic resistance genes
IV. Inactivation of the gene for synthesis of β-galactosidase
Insertional inactivation results in the inactivation of the gene for $eta$-galactosidase synthesis. Non-recombinant colonies produce blue colour. Recombinant colonies do not produce color (white). Selection using two antibiotic resistance genes requires simultaneous plating on two plates.
