The technique of DNA fingerprinting was developed by which scientist?
- A.Alec Jeffreys
- B.Kary Mullis
- C.Har Gobind Khorana
- D.Paul Berg
Correct answer
Explanation
The correct answer is A, Alec Jeffreys. The British geneticist Alec Jeffreys developed DNA fingerprinting in 1984 by studying short repeated sequences that vary in number from person to person, and the method is now used in criminal investigation, in disputes about parentage and in identifying victims of accidents and disasters. Option B, Kary Mullis, invented the polymerase chain reaction and won the Nobel Prize in Chemistry in 1993, and since the reaction is used in fingerprinting the two names are often exchanged. Option C, Har Gobind Khorana, shared the Nobel Prize in 1968 for work on the genetic code and the synthesis of nucleic acids, which is earlier and different work. Option D, Paul Berg, made the first recombinant DNA molecule. In India this work is done at the Centre for DNA Fingerprinting and Diagnostics at Hyderabad.
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Practice Questions
View allWhich enzyme cuts DNA at a specific recognition sequence and is therefore called molecular scissors?
- A.DNA ligase
- B.Restriction endonuclease
- C.DNA polymerase
- D.Reverse transcriptase
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A restriction endonuclease recognises a short palindromic sequence in DNA and cuts both strands there, leaving sticky ends that can pair with another piece cut by the same enzyme; Hind II was the first such enzyme to be discovered and EcoRI from Escherichia coli is the most widely used.
Read the full explanation →Which bacterium is used as a natural vector to transfer genes into plant cells?
- A.Escherichia coli
- B.Agrobacterium tumefaciens
- C.Bacillus thuringiensis
- D.Rhizobium leguminosarum
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This soil bacterium naturally transfers a part of its tumour inducing plasmid, called the Ti plasmid, into the cells of a dicotyledonous plant and causes crown gall disease; genetic engineers disarm the plasmid, insert the gene they want and use the bacterium as a vector, which is why it is…
Read the full explanation →The insect resistance gene of Bt cotton is obtained from which organism?
- A.A virus
- B.A soil bacterium
- C.A fungus
- D.An alga
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The genes called cry genes are taken from Bacillus thuringiensis, a bacterium of the soil that forms protein crystals during its spore stage.
Read the full explanation →Golden Rice is a genetically modified variety enriched with which substance?
- A.Iron
- B.Beta carotene
- C.Lysine
- D.Vitamin C
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Golden Rice carries genes that let the grain make beta carotene, the orange pigment that the human body converts into vitamin A, and the colour of the grain gives the variety its name; the aim is to reduce night blindness and childhood blindness in populations whose diet is mainly rice.
Read the full explanation →Which heat stable enzyme is used in the polymerase chain reaction?
- A.Taq polymerase
- B.DNA ligase
- C.EcoRI
- D.Lysozyme
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The polymerase chain reaction repeats three steps, denaturation at a high temperature, annealing of short primers and extension of the new strand, so the enzyme must survive near boiling water; Taq polymerase, obtained from the bacterium Thermus aquaticus of hot springs, does exactly that and lets a single DNA segment…
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