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The correct answer is (b) 100-1000

Best explanation: Bioreactor is a device or vessel which helps in carrying out various biological reactions providing them OPTIMUM conditions. It helps in the PROPER growth of organisms giving US the DESIRED product with its high yield.

Correct answer is (a) antibiotic-resistance

Best explanation: The transformants which will be SUCCESSFULLY transformed and consisting of an antibiotic-resistance gene will grow on plates CONTAINING ANTIBIOTICS. This gene can act as a SELECTABLE marker to DIFFERENTIATE between transformants and non-transformants. The non-transformants will not grow on a plate containing antibiotics and will eventually die.

Correct answer is (d) Polymerase chain REACTION

Easy explanation: PCR stands for Polymerase chain reaction. It is a technique used for DNA amplification. It was DEVELOPED by Kary Mullis and is a useful technique in GENETIC engineering.

Right answer is (c) DENATURATION, annealing, and extension

For explanation: Denaturation, annealing, and extension are THREE steps involved in PCR. In denaturation, the DNA is DENATURED. The PRIMERS are ADDED in annealing and in extension, the primers extend giving rise to new DNA strands.

The correct answer is (c) anode

Easiest explanation: During agarose GEL electrophoresis the DNA MOVES towards the anode. Since DNA is NEGATIVELY CHARGED it moves toward the positively charged terminal. An anode is a positive terminal while the CATHODE is the negative terminal.

The correct answer is (b) Ligase

Best explanation: LIGASES are the enzyme that helps in the JOINING of two strands of DNA. LYASE is responsible for the breakdown of molecules. Helicase helps in the UNWINDING of DNA. Lipases are enzymes that breakdown lipids.

The correct answer is (d) Ethanol

Best explanation: Ethanol is USED to obtain the precipitate of PURE DNA. It’s used in CONCENTRATING and de-salting of NUCLEIC ACIDS. It makes the nucleic acid less hydrophilic thus easing their extraction.

Correct option is (a) protease

Explanation: The enzyme which cleaves proteins is a protease. RNase is the enzyme that cleaves the RNA. LIPASES are responsible for the breakdown of lipids while DNASE CATALYZES the breakdown of DNA.

Right choice is (b) Histone

The explanation is: The DNA is WOUND around histone proteins. They are alkaline in nature which helps in packaging and condensation of DNA. DNA wound around histone forms a COMPLEX CALLED a nucleosome.

The correct option is (b) exponential phase

The best I can EXPLAIN: The log (logarithmic) phase of the bacterial growth curve is also known as the exponential phase. It is the second phase of the bacterial growth curve. In this phase the bacteria that have adapted to the NEW ENVIRONMENT doubles. Thus, the maximum growth RATE is SEEN in this phase.

The CORRECT choice is (a) separation and purification

Easiest explanation: Downstream processing is the various stages that OCCUR after the completion of the fermentation process. It refers to the recovery and purification of various BIOSYNTHETIC PRODUCTS that are beneficial for HUMANS. It also involves stages such as separation and purification.

Right answer is (c) 4

To explain I would SAY: A typical bacterial growth curve has FOUR distinct PHASES, namely log phase, lag/exponential phase, stationary phase, and death/decline phase. Bacteria divide with the help of binary fission. Few other micro-organisms such as algae, PROTOZOA, yeasts ALSO show these same growth phases.

The correct OPTION is (c) Stirrer

For explanation: Bioreactor is a device or vessel which helps in carrying out various biological reactions providing them OPTIMUM conditions. The stirrer facilitates the even MIXING of INGREDIENTS like broth, the air in a bioreactor. This stirrer is ALSO known as impellers.

The CORRECT option is (d) Optimum

Easiest EXPLANATION: Optimum means favorable. These CONDITIONS favor the growth of bacteria and maximum growth is seen when the cells are provided with optimum conditions. Maximum growth leads to maximum PRODUCT yield.

The correct choice is (b) Continuous

Easiest EXPLANATION: The continuous culturing method PRODUCES the cells which are in the same PHASE i.e. exponential phase. SINCE all cells are in the same phase. This TYPE of culturing method produces higher biomass and yields the maximum desired product.

Right option is (c) recombinant

To explain I WOULD say: A protein ENCODED by a GENE of recombinant DNA is called a recombinant protein. The heterologous host is the host responsible for producing proteins that they are not supposed to produce that is they express the genes which are ARTIFICIALLY INCORPORATED within them.

The correct option is (c) Continuous

To explain: The continuous culture SYSTEM is USED to obtain the cells in the exponential PHASE. In continuous culture, the FRESH media is added from one side while the used media is SIMULTANEOUSLY drained from the other side. This helps to obtain cells in a single phase.

Right answer is (d) HERBERT Boyer

Best explanation: Recombinant DNA technology is ASSOCIATED with Herbert Boyer since he invented it along with Stanley Cohen. He worked on restriction enzymes FOUND in E.coli. He invented DNA CLONING which led to the discovery of several recombinant PROTEINS such as insulin.

Correct choice is (a) selectable

Best explanation: The antibiotic resistance gene can be used as a selectable marker for SELECTING transformants. This gene CONFERS the trait for artificial SELECTION and may code for resistance to any antibiotic such as ampicillin, penicillin, kanamycin, tetracycline, etc. The successful transformants will grow on antibiotic-containing media.

The CORRECT CHOICE is (b) E.coli

Best explanation: E.coli is the bacteria most commonly USED in genetic engineering. It is a model organism. It can be EASILY and inexpensively cultured within a laboratory. It GROWS at a faster rate and has a doubling time of approximately 20 minutes.

The correct choice is (b) ribonuclease

The best I can explain: Ribonuclease is the enzyme responsible for CATALYZING the cleavage of RNA. RNA STANDS for ribonucleic acid. It is also KNOWN as RNase. It also cleaves the DNA-RNA HYBRIDS.

Right choice is (a) Monosaccharide

Easy EXPLANATION: Carbohydrates are made up of MONOSACCHARIDES. It is the sugar that cannot be HYDROLYZED further. They come TOGETHER to form a disaccharide which further goes on forming a carbohydrate. They are the major source of energy for living BEINGS.

The correct option is (C) Fatty acids

Explanation: LIPID is a macromolecule made up of fatty acids and glycerol. A fatty acid CONSISTS of carboxylic acid along with an aliphatic chain. This chain can be saturated (single bond) or UNSATURATED (double or triple bonds).

Correct answer is (d) LIPIDS, polysaccharides

The best I can EXPLAIN: Along with DNA the cell also consists of various MACROMOLECULES such as lipids, RNA, polysaccharides. A macromolecule is a LARGE MOLECULE that is formed by polymerization of monomers. A macromolecule consists of more than 100 monomers.

Right choice is (b) PURE

The explanation is: The RESTRICTION enzyme needs to be in pure form to cut the DNA. The restriction ENZYMES are molecular SCISSORS that cleave the DNA at specific recognition sites. Restriction enzymes are also known as restriction endonucleases or restrictase.

Right OPTION is (c) chitinase

To explain I would say: The fungal CELL wall consists of CHITIN as the major component. Chitinase is the enzyme used for the BREAKDOWN of chitin. This enzyme breaks down the glycosidic bonds present in the chitin. This enzyme is usually PRODUCED by higher plants for their protection.

The correct option is (c) DNase

The explanation: The enzyme which cleaves DNA is DNase. It CATALYZES the breakdown of phosphodiester LINKAGES of DNA. It is a type of endonuclease. Ligases are the enzymes used in the joining of TWO strands.

Right ANSWER is (d) cellulase

Easy EXPLANATION: Cellulase is the enzyme used for the LYSIS of plant cells. It catalyzes cellulolysis, which is the breakdown of cellulose. Cellulase acts on the glycosidic linkages of cellulose. Cellulose is MOSTLY found in plant cell walls along with other components.

Right option is (b) lysozyme

To explain I would say: The ENZYME USED for breaking or lysis of bacterial CELLS is lysozyme. It helps in the BREAKDOWN of CARBOHYDRATES found in a bacterial cell. It is also found in tears.

The correct choice is (b) Biolistics

The explanation is: Biolistics or gene gun is the method that uses a ‘disarmed PATHOGEN’ vector. A pathogen from which virulence or disease-causing genes are removed is known as a disarmed pathogen. It is a process in which DNA is transferred into a HOST WITHOUT any RISK of infection.

Correct ANSWER is (a) Aurum

To explain: The microparticles of GOLD-coated with DNA are used in gene gun technique. Aurum is a LATIN word for gold. Other METAL used for this technique is TUNGSTEN.

The CORRECT choice is (c) divalent

To explain I would say: CALCIUM is a divalent CATION. It has a valency of 2 and is WRITTEN as Cu^2+. Some other examples of divalent atoms are Zn^2+, Mg^2+, Co^2+, ETC.

Correct option is (c) 42°C

For explanation: 42°C-45°C is the ideal TEMPERATURE for heat-shock treatment. Mostly calcium chloride is USED in this. It is suitable for the TRANSFORMATION of BACTERIAL cells such as E.coli.

Right option is (d) gene gun

Explanation: Biolistics is also known as a gene gun. It is a method in which cells are BOMBARDED with high-velocity micro-particles of GOLD or tungsten COATED with DNA. It is mostly USED for PLANT cells.

The correct choice is (b) micro-injection

To elaborate: The method by which recombinant DNA is directly injected into the nucleus of an ANIMAL cell is called micro-injection. A GLASS micropipette is USED for injecting the material into cells.

The correct choice is (C) heat-shock treatment

Easy explanation: Heat-shock treatment is a method in which the vial is INCUBATED in ice, then treated at temperature up to 50°C and again TRANSFERRED on ice. It is usually used in transferring recombinant DNA within the HOST (bacterial cell).

Right option is (d) Calcium

To elaborate: The DIVALENT cations of calcium are used to make cells COMPETENT. Calcium is used in the form of a salt of calcium CHLORIDE. It increases the EFFICIENCY of the bacterial membrane to allow the passage of FOREIGN DNA.

Right CHOICE is (B) DNA

The best EXPLANATION: DNA is an example of a hydrophilic molecule. Hydrophilic molecules are water-loving and tend to dissolve in water easily. They carry a POSITIVE or negative CHARGE.

Correct ANSWER is (a) HYDROPHILIC molecule

Easiest EXPLANATION: The molecule which dissolves in water is CALLED hydrophilic molecules. They are polar in nature which helps them in dissolution in water. Being hydrophilic in nature DNA cannot pass through the cell membrane.

The correct answer is (b) Ti

To explain I would say: The Ti plasmid in Agrobacterium tumifaciens LEADS to tumor formation in dicots. ‘Ti’ STANDS for tumor-inducing. It may CONTAIN more than ONE T-DNA region. This plasmid is modified and used as a cloning vector.

The correct option is (a) Agrobacterium tumifaciens

The EXPLANATION is: Agrobacterium tumifaciens is the bacteria which TRANSFERS ‘T-DNA’ within plants. It mostly infects DICOT plants. This ‘T-DNA’ is RESPONSIBLE for the formation of transformed cells called tumors from normal PLANT cells.

Right ANSWER is (c) More than one recognition site

The best explanation: Recognition site is the sequence of DNA where the DNA is cleaved. The presence of more than one recognition site will lead to SEVERAL cuts within DNA leading to FRAGMENTATION of DNA. This will complicate the process of gene cloning.

The correct answer is (c) INSERTIONAL inactivation

For explanation I would say: Insertional inactivation is the process in which the gene is inactivated due to the insertion of other genes within it or within its coding sequence. This LEADS to loss of FUNCTION of that specific gene. THUS, insertion of recombinant DNA within the gene encoding for β–galactosidase will lead to insertional inactivation.

Right answer is (d) Kanamycin

Easiest explanation: Antibiotics are the SUBSTANCES that either INHIBIT the growth or kill bacteria. They are widely USED to TREAT diseases caused by bacteria. Some examples of antibiotics are kanamycin, ampicillin, penicillin, tetracycline, etc.

Correct OPTION is (b) TRANSFORMATION

To explain I WOULD say: Transformation is a process in which a FOREIGN DNA is directly picked up by the bacteria from the surrounding environment. It leads to a change in the characteristics of bacteria. It was first observed by GRIFFITH in 1928.