Biotechnology and its Applications MCQs for NEET — Zoology Questions with Answers

(d) Taq polymerase is a thermostable DNA polymerase obtained from Thermus aquaticus.

Theimusaquaticus is a bacterium that lives in hot springs and hydrothermal vents.

The DNA molecule to which the gene of interest is integrated for cloning is called vector. It is a DNA molecule used as a vehicle to artificially carry foreign genetic material into another cell, where it can be replicated and/for expressed. A vector containing foreign DNA is termed as recombinant DNA.

Plasmid is a small fragment of DNA (about 10 Kbp size) that is physically separate form and can replicate freely of chromosomal DNA within a cell. It can clone small DNA fragments.

Cosmid-45 Kbp

BAC-300-350 Kbp

YAC-1 Mbp/1,000 Kbp-2,500 Kbp)

DNA fragments generated by restriction endonucleases can be separated based on their size using a technique called gel electrophoresis. It involves applying an electric field to separate DNA fragments through a porous gel matrix, with smaller fragments moving faster than larger ones.

(c) Algae is a plant and so its cell wall is made up of cellulose. Cellulase enzyme is needed for degradation of its cell wall.

The hypervariable regions of DNA have Variable Number of Tandem repeats (VNTRs) of short

nucleotide sequences which are specific for each individual (except for monozygotic twins). Variations

also occur due to mutations, small deletions or insertions. Therefore, DNA cut by a particular

endonuclease will have different lengths in different persons. This phenomenon is called Restriction

Fragment Length Polymorphism. It is the basis of genetic (or DNA) fingerprinting and is useful in

identifying individuals from their semen, blood or tissues or any other DNA sample and resolution of

parent hood disputes. Polymerase Chain Reaction (PCR) is also useful in genetic fingerprinting as it can

amplify the DNA sample even if available in a very small amount.

Probes are 15-30 bases long radioactive labelled oligonucleotides (RNA or DNA) used to detect complementary nucleotide sequences, used for disease diagnosis, etc.

Polymerase Chain Reaction (PCR) is used to amplify a DNA segment or to synthesize in vitro the multiple copies of gene (or DNA) of interest, using two sets of primers and the enzyme DNA polymerase. This enzyme is isolated from a bacterium Thermus aquaticus and it remains active during the high temperature but high temperature induced denaturation of double stranded DNA.

Biolistics or gene gun is a direct or vectorless way used to introduce alien DNA into host cells. In this method of gene transfer, high velocity micro-particles of gold or tungsten, coated with DNA are bombarded on the plant cells.

Palindromic DNA is a base sequence of DNA, which reads the same forward or backward. It has similar sequence in both the strands. Different types of palindromic sequences are recognised by restriction endonucleases.