Match the component in List-I essential for Polymerase Chain Reaction (PCR) with its function or description in List-II:
List-I (PCR Component)
List-II (Function/Type)
A. Thermostable DNA Polymerase
I. Small chemically synthesised oligonucleotides
B. Primers
II. Isolated from Thermus aquaticus
C. Genomic DNA
III. Template for primer extension
D. In vitro synthesis target
IV. Multiple copies of the gene of interest
Thermostable DNA polymerase is isolated from *Thermus aquaticus* [44, II]. Primers are small chemically synthesised oligonucleotides [44, I]. Genomic DNA serves as the template [44, III]. The goal is to synthesize multiple copies of the gene of interest [43, IV].
Question 412 of 535
📘 CLASS XII
Match the specialized bioreactor components in List-I with their functions in List-II:
List-I (Component)
List-II (Function)
A. Foam Control System
I. Allows periodic withdrawal of culture volumes
B. Sampling Ports
II. Manages unwanted foaming during agitation/sparging
C. Sparged Bioreactor
III. Sterile air bubbles are bubbled (sparged) through
D. Curved Base/Cylindrical Shape
IV. Facilitates proper mixing of reactor contents
Foam control system manages foam [50, II]. Sampling ports allow withdrawal of culture volumes [50, I]. In a sparged bioreactor, sterile air bubbles are sparged through [52, III]. The shape (cylindrical or curved base) facilitates mixing [49, IV].
Question 413 of 535
📘 CLASS XII
Match the contaminant/component in List-I with the substance/enzyme used for its removal or precipitation during DNA isolation (List-II):
List-I (Contaminant)
List-II (Enzyme/Agent Used for Removal)
A. RNA
I. Protease
B. Proteins (e.g., Histones)
II. Ribonuclease
C. Cell Wall of Fungus
III. Chitinase
D. Precipitation of DNA
IV. Chilled Ethanol
RNA is removed by ribonuclease [41, II]. Proteins are removed by protease [41, I]. Fungal cell wall is broken by chitinase [40, III]. DNA is precipitated by chilled ethanol [41, IV].
Question 414 of 535
📘 CLASS XII
Match the cloning site requirements in List-I with their associated reasoning or location in List-II:
List-I (Cloning Site Requirement)
List-II (Reason/Consequence)
A. Few, preferably single recognition sites
I. The ligation of alien DNA is carried out here
B. Restriction site location in vector
II. Will generate several fragments, complicating gene cloning
C. Presence of more than one recognition site
III. To ensure simple gene cloning process
D. BamH I site in pBR322
IV. Located in the tetracycline resistance gene
A vector needs few recognition sites for simple cloning [29, III]. Ligation is carried out at the restriction site [29, I]. Multiple recognition sites complicate cloning by generating several fragments [29, II]. BamH I is located within the *tetR* gene [29, IV].
Question 415 of 535
📘 CLASS XII
Match the natural or modified pathogen in List-I with the host transformation process in List-II:
List-I (Natural Pathogen)
List-II (Host Cell Transformation)
A. Agrobacterium tumifaciens (natural)
I. Transformation of animal cells into cancerous cells
B. Retroviruses (natural)
II. Transformation of normal plant cells into tumor cells
C. Disarmed Ti Plasmid
III. Delivering genes of interest into plant host cells
D. Disarmed Retroviruses
IV. Delivering desirable genes into animal host cells
*A. tumifaciens* naturally transforms plant cells into tumors [34, II]. Retroviruses naturally transform animal cells into cancerous cells [34, I]. Disarmed Ti plasmid (modified *A. tumifaciens*) is used for gene delivery into plants [35, III]. Disarmed retroviruses are used to deliver desirable genes into animal cells [35, IV].
Question 416 of 535
📘 CLASS XII
Match the key term in List-I related to modern biotechnology with its definition or goal in List-II:
List-I (Term)
List-II (Definition/Goal)
A. Recombinant Protein
I. Techniques to alter the chemistry of genetic material
B. Genetic Engineering
II. Maintenance of sterile ambiance
C. Bioprocess Engineering
III. Protein encoding gene expressed in a heterologous host
D. Ultimate Aim of RDT
IV. To produce a desirable protein
A recombinant protein is expressed in a heterologous host [48, III]. Genetic engineering alters the chemistry of genetic material [7, I]. Bioprocess engineering maintains sterile ambiance [8, II]. The ultimate aim of RDT is to produce a desirable protein [47, IV].
Question 417 of 535
📘 CLASS XII
Match the DNA visualization step in List-I with its corresponding compound or result in List-II:
List-I (Visualization Step)
List-II (Compound/Result)
A. Staining of DNA fragments
I. Cannot be seen (without staining)
B. Pure DNA fragments in visible light
II. Ethidium bromide
C. Exposure to UV radiation
III. Results in bright orange bands
D. DNA bands in stained gel
IV. Cut out from the gel piece (Elution)
DNA is stained with ethidium bromide [24, II]. Pure DNA fragments are invisible in visible light [24, I]. UV exposure results in bright orange bands [24, III]. Separated bands are cut out (elution) [24, IV, 25].
Question 418 of 535
📘 CLASS XII
Match the enzyme or enzyme source in List-I with its description or origin in List-II:
List-I (Enzyme/Source)
List-II (Origin/Type)
A. EcoRI
I. Bacterium Thermus aquaticus
B. Taq Polymerase
II. Isolated from Haemophilus influenzae (Implied from Hind II context)
C. Hind II
III. Isolated from Escherichia coli RY 13
D. Nucleases
IV. Larger class of enzymes including Restriction Endonucleases
EcoRI is isolated from *Escherichia coli* RY 13 [17, III]. Taq Polymerase is isolated from *Thermus aquaticus* [44, I]. Hind II is implicitly stated to be derived from *H. influenzae* based on its name (H=Genus, in=species), although the full name is not given in the text, its naming follows the convention derived from its source organism [17, II]. Nucleases are the larger class of enzymes to which REs belong [18, IV].
Question 419 of 535
📘 CLASS XII
Match the component of color-based selection in List-I with its result or function in List-II:
List-I (Element)
List-II (Description/Result)
A. $eta$-galactosidase gene
I. Colonies appear white (no color produced)
B. Non-recombinant colonies (with intact gene)
II. Colonies appear blue (produce color)
C. Recombinant colonies (with insert)
III. Coding sequence where RDNA is inserted for color selection
D. Chromogenic substrate
IV. Used to differentiate recombinants from non-recombinants based on color production
RDNA is inserted within the coding sequence of the $eta$-galactosidase gene [32, III]. Non-recombinant colonies have an intact gene and produce blue color [33, II]. Recombinant colonies have the gene inactivated and do not produce color (white) [33, I]. Chromogenic substrate allows differentiation based on color production [32, IV].
Question 420 of 535
📘 CLASS XII
Match the stage of DNA isolation (List-I) with the corresponding technique or substance used (List-II):
List-I (Process of RDNA Technology)
List-II (Related Step)
A. Release of DNA
I. Treatment with chilled ethanol
B. Removal of proteins
II. Treatment with lysozyme, cellulase, or chitinase
C. Precipitation of purified DNA
III. Treatment with protease
D. Recovery of DNA threads
IV. Spooling (fine threads are removed)
DNA is released by breaking the cell open using enzymes like lysozyme/cellulase/chitinase [40, II]. Proteins are removed by treatment with protease [41, III]. DNA is precipitated by chilled ethanol [41, I]. DNA threads are removed by spooling [41, IV].
