In eukaryotes which of the following is removed from initially transcribed RNA before it is transported to the cytoplasm for translation ?
(2) 3' Poly A tail
(3) Ribosome binding site
(4) 5' cap
(1) The introns are non coding sequences in the transcript of the split gene of eukaryotes. RNA splicing removes introns and joins exons forming the function cistron.
The process of splicing in eukaryotes :
(1) is reminiscent of antiquity
(2) represents dominance of RNA world
(3) is an indicator of the complexity of human genome
(4) is a legacy of organic evolution
(2) Splicing is possible in RNA as metabolic machinery has evolved around RNA. This is not possible in DNA.
In prokaryotes, the predominant site for control of gene expression is the :
(1) transcription initiation
(2) processing level
(3) transport of mRNA
(4) translation level
(1) Transcription initiation is binding of RNA polymerase to the promoter. If you remember operon this is the point of regulation of gene expression in prokaryotes.
In Hershey and Chase experiment, what finding led to the conclusion that DNA is the genetic material ?
(1) The presence of radioactivity in the bacteria when 35S was used.
(2) The presence of radioactivity in the supernatant when 35S was used.
(3) The presence of radioactivity in the bacteria when 32P was used.
(4) The presence of radioactivity in the supernatant when 32P was used.
(3) Radioactive phosphorus would label the DNA but not proteins.
Which of the following important biochemical reactions in living systems is catalyzed by a ribozyme?
(1) Repair of DNA
(2) Electron transport chain
(3) Formation of peptide bond
(4) Organization of MTOC during cell division
(3) In prokaryotes the 23srRNA of the larger subunit of ribsome is a ribozyme that catalyzes peptide bond formation.
VNTR are useful in DNA profiling because they:
I. Are hypervariable
II. Are inherited
III. Synthesize constitutiveenzymes
(1) I, II, III are correct
(2) I and II are correct
(3) I and III are correct
(4) II and III are correct
(2) VNTR are mini-satellite repeats that do not code for any protein.
Which enzyme polymerizes RNA with defined sequences in a template independent manner?
(1) Peptidyl transferase
(2) RNA polymerase
(3) Reverse transcriptase
(4) Polynucleotide phosphorylase
(4) This is Severo Ochoa enzyme.
The process of RNA splicing shows the dominance of :
(1) DNA world
(2) RNA world
(3) Protein world
(4) Microbial world
(2) The metabolic machinery has evolved around RNA.
In RNA splicing :
(1) Exons are removed and introns are joined together
(2) Introns are removed and exons are joined together
(3) Cistrons are removed and introns are joined together
(4) Introns are removed and Cistrons are joined together
(2) Introns are non-coding sequences in a split gene.