Question

answer all the questions

18) A mutation occurs such that a spliceosome cannot remove one of the introns in a gene. What effect will this have on the gene? Translation will continue, but a nonfunctional protein will be made b) Translation will continue and will skip the intron sequence c) It will have no effect; the gene will be transcribed and translated into protein d) Transcription will terminate easily and the protein will not be made 19. During the process of translation: A) the peptide is 'passed from the tRNA in the P-site to the tRNA in the A-site. B) incoming tRNAs must first bind to the E-site. C) initiation begins with the binding of the ribosomal SSU to the poly-A tail of the mRNA. D) the mRNA is translated by one ribosome at a time. 20) The presence of a poly-A tail on a RNA molecule indicates that: A. there are exons present that must be removed. B. this RNA molecule does not contain introns. C. the transcript should be immediately degraded. D. this is a rRNA molecule. E. None of the above answers is correct 21)A proteasome" is a large structure in the cytoplasm that: A. translates mRNA into protein B. supercoils DNA C. processes RNA D. enzymatically degrades proteins 22) During the 'elongation stage of translation, after the arrival of each new tRNA: A) The amino acid is ‘passed' from the tRNA in the A-site to the tRNA in the P-site. B) Newly arriving RNAs must first bind to the E-site. C) The peptide is 'passed from the RNA in the P-site to the tRNA in the A-site. D) The new tRNA must first bind to the P-site of the ribozome.

Answer 1

Answer 18- a) translation will continue, but a non-functional protein will be made.

Reason- If the spliceosome fails to remove an intron due to mutation, a mRNA with junk will be made, and get translated into a wrong protein.

Answer 19- c) initiation begins with the binding of ribosomal SSU to the poly-A tail of mRNA.

Reason- During translation, the tRNA at the A site moves to the P site through translocation.

The initiator tRNA first binds directly to the P site of the small ribosomal subunit.

Multiple ribosomes can translate a single mRNA molecule at the same time.

Answer 20- b) this RNA molecule doesnot contain introns.

Reason- A poly-A tail is added to an RNA at the end of transcription, i.e introns have been removed.

Answer 21- d) Enzymatically degrades protein.

Reason- The main function of the proteasome is to degrade unwanted or damaged proteins by proteolysis.

Answer 22- c) the peptide is 'passed' from the tRNA in the P-site to the tRNA in the A-site.

Reason-the initiator tRNA binds to the P-site of the ribosome.

Answer 23- c) the peptide is 'passed' from the tRNA in the P-site to the tRNA in the A-site.

Answer 24- e) small nuclear RNAs

Reason- translation initiation involves the mRNA, ribosomal small subunit, translation initiation factors and the initiator tRNA.

Answer 25- a) it is a RNA virus, as it contains uracil instead of thymine.

b) single stranded.