Multiple Choice QuestionsRemoval of introns and joining the exons in a defined order in transcription unit is called
splicing
tailing
transformation
transformation
Whose experiments cracked the DNA and discovered unequivocally that is genetic code is a triplet?
Nirenberg and Mathaei
Hershey and Chase
Morgan and Sturtevant
Morgan and Sturtevant
A.
Nirenberg and Mathaei
The existence of a triplet code was simply an assumption till 1961 when Nirenberg and Methaei proved its existence by experiment. They were able to synthesise artificial mRNA, which contained only one nitrogenous base, ie, uracil. This synthetic poly-U sequence was then placed in a cell-free system containing protein synthesizing enzymes (extracted from bacterium E. coil) and 20 amino acids together with necessary ATP. During the process, a small polypeptide molecule was produced, which was formed by the linking of phenylalanine. This issuggested that UUU is code for phenylalanine. Nirenberg got Nobel Prize for his contributions.
select the incorrect statement from the following
Linkage is an exception to the principle of independent assortment in heredity
galactosemia is an inborn error of metabolism
small population size results in a random genetic drift in a population
small population size results in a random genetic drift in a population
Semiconservative replication of DNA was first demonstrated in
Drosophila melanogaster
Escherichia Coli
Streptococcus pneumoniae
Streptococcus pneumoniae
Transgenic plants are
produced by a somatic embryo in an artificial medium
generated by introducing foreign DNA into a cell and regenerating a plant from that cell
Produced by protoplast fusion in the artificial medium
Produced by protoplast fusion in the artificial medium
What is not true for genetic code?
A condon in mRNA is read in a non-contiguous fashion
It is nearly universal
It is degenerate
It is degenerate
Given below is the diagram of a bacteriophage in which one of the options, all the four parts A, B, C and D are correct?
|
A |
B |
C |
D |
|
Tail fibres |
Head |
Sheath |
Collar |
|
A |
B |
C |
D |
|
Sheath |
Collar |
Head |
Tail fibres |
|
A |
B |
C |
D |
|
Head |
Collar |
Sheath |
Tail fibres |
|
A |
B |
C |
D |
|
Head |
Collar |
Sheath |
Tail fibres |
Gel electrophoresis is used for
cutting of DNA into fragments
separation of DNA fragments according to their size
construction of recombinant DNA by joining with cloning vectors
construction of recombinant DNA by joining with cloning vectors
Polymase is formed by
several ribosomes attached to a single mRNA
many ribosomes attached to a strand of endoplasmic reticulum
a ribosome with several subunits
a ribosome with several subunits
In the DNA molecule
the total amount of purine nucleotides and pyrimidine nucleotides is not always equal
there are two strands, which run parallel in the 5' →3' direction
the proportion of adenine in relation to thymine varies with organism
the proportion of adenine in relation to thymine varies with organism
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