Free Biotechnology MCQs with Answers

• A. Meloidogyne incognita
• B. Agrobacterium tumefaciens
• C. Penicillium expansum
• D. Trichoderma harzianum

Explanation: Agrobacterium tumefaciens has been extensively used in genetic engineering experiments.

• A. Construction of recombinant DNA by joining with cloning vectors.
• B. Isolation of DNA molecules.
• C. Cutting of DNA into fragments.
• D. Separation of DNA fragments according to their size.

Explanation: Electrophoresis is a technique used for the separation of substances of different ionic properties.

• A. DNA polymerase
• B. Exonucleases
• C. DNA ligase
• D. Endonucleases

Explanation: The construction of the first recombinant DNA emerged from the possibility of linking a gene encoding antibiotic resistance with a native…

• A. Synthesizes DNA
• B. Cuts the DNA molecule randomly.
• C. Cuts the DNA molecule at specific sites
• D. Restricts the synthesis of DNA inside the nucleus.

Explanation: Restriction endonucleases were found by Arber in 1962 in bacteria. They act as "molecular scissors" or chemical scalpels.

• A. Crown gall bacterium and Caenorhabditis elegans
• B. Escherichia coli and Agrobacterium tumefaciens
• C. Vibrio cholerae and a tailed bacteriophage
• D. Diplococcus sp. and Pseudomonas sp.

Explanation: E.coli contains many important standard cloning vectors widely used in gene cloning experiments like pBR322 contains origin of replication…

• A. Are present in mammalian cells for degradation of DNA when the cell dies
• B. Are used in genetic engineering for ligating two DNA molecules
• C. Are used for in vitro DNA synthesis
• D. Are synthesized by bacteria as part of their defense mechanism.

Explanation: Restriction endonucleases are enzymes that digest double stranded DNA following recognition of specific nucleotide sequences.

• A. Enhancer
• B. Transgene
• C. Promoter
• D. Reporter

Explanation: The plants, in which a functional foreign gene has been incorporated by any biotechnological methods that generally is not present in the…

• A. They are small and therefore, easy to study.
• B. They are uniparental in origin and do not take part in recombination
• C. Their structure is known in greater detail
• D. They can be studied from the samples of fossil remains.

Explanation: Sequence of both mtDNA and Y chromosomes are considered for the study of human evolution because they are uniparental in origin.

• A. Clostridium septicum
• B. Xanthomonas citri
• C. Bacillus coagulens
• D. Agrobacterium tumefaciens

Explanation: Agrobacterium tumefaciens has been extensively used in genetic engineering experiments.

• A. Restriction endonuclease
• B. DNA ligase
• C. Transcriptase
• D. Primase

Explanation: DNA restriction endonuclease is an important class of restriction exonucleases, class II, which cut double­stranded DNA molecules only at…

• A. Bacteriophage transforms in wild.
• B. It is not mutated.
• C. Both strains have similar cistrons.
• D. Both strains have different cistrons.

Explanation: A mutant strain of T4 - bacteriophage, RII, fails to lyse the E.coli but when two strains R-­II (X) and R-­IIY are mixed then they lyse…

• A. Minimal medium and Streptomycin
• B. Complete medium and Streptomycin
• C. Only minimal medium
• D. Only complete medium.

Explanation: If Streptomycin resistant mutant is to be obtained, the material should be allowed to grow on medium lacking streptomycin so that both…

• A. 50 kilo base
• B. 500 kilo base
• C. 5000 kilo base
• D. 5 kilo base.

Explanation: A plasmid is a DNA molecule separate from the chromosomal DNA and capable of autonomous replication.

• A. It is circular DNA which have capacity to join to eukaryotic DNA.
• B. It can move between prokaryotic and eukaryotic cells.
• C. Both ends show replication.
• D. It has antibiotic resistance gene.

Explanation: Plasmid and bacteriophage are used as vectors in genetic engineering. Plasmid is an autonomously replicating circular extra chromosomal…

• A. Mitochondrial gene
• B. Plasmid gene
• C. Bacterial gene
• D. None of these.

Explanation: The DNA plasmid replicates in a semi­ conservative manner. The initiation of replication is controlled by the plasmid gene and elongation…

• A. Ligase
• B. Restriction endonulcease
• C. Primase
• D. Exonucleases.

Explanation: Recombinant DNA is the product obtained after isolating a specific DNA segment and then inserting it into another DNA molecule at a…

• A. Nitrobacter and Azotobacter
• B. Rhizobium and Diplococcus
• C. Nitrosomonas and Kliebsiella
• D. Escherichia and Agrobacterium

Explanation: E.coli contains many important standard cloning vectors widely used in gene cloning experiments like pBR322 contains origin of replication…

• A. Used for in vitro DNA synthesis.
• B. Used in genetic engineering.
• C. Synthesized by bacteria.
• D. Present in mammalian cells for degradation of DNA.

Explanation: Restriction endonucleases were found by Arber in 1962 in bacteria. They act as "molecular scissors" or chemical scalpels.

• A. We can cut DNA at specific sites by endonucleases like DNase I.
• B. Restriction endonucleases purified from bacteria can be used in vitro.
• C. The phenomenon of transduction in bacteria is well understood.
• D. We can see DNA by electron microscope.

Explanation: DNA restriction endonuclease are an important class of restriction exonucleases, class II, which cut double­stranded DNA molecules only at…

• A. They can cut DNA at specific base sequence.
• B. They are nucleases that cut DNA at variable sites.
• C. They can degrade harmful proteins.
• D. They can join different DNA fragments.

Explanation: DNA restriction endonuclease are important class of restriction exonucleases, class II, which cut double­stranded DNA molecules only at…