Multiple Choice QuestionsThe binding site of tRNA with mRNA & amino acids respectively are
mRNA with DHU loop and amino acid with CCA end.
mRNA with CCA end and amino acid with anticodon loop
mRNA with anticodon loop and amino acid with DHU loop
mRNA with anticodon loop and amino acid with CCA end
During protein synthesis in an organism at one point the process comes to a halt. Select the group of the three codons from the following, from which any one of the three could bring about this halt.
UUU, UCC, UAU
UUC, UUA, UAC
UAG, UGA, UAA
UUG, UCA, UCG
C.
UAG, UGA, UAA
Non-sense codon or terminator codon are the codons that do not code for any amino acid. It is a set of three nucleotides for which there is no corresponding tRNA molecule to insert an amino acid into the polypeptide chain. Protein synthesis is hence terminated and the completed polypeptide released from the ribosome. Three stop codons are UAA (ochre), UAG (amber) and UGA (opal).
Mutations which generate any of these three codons in a position which normally contains a codon specifying an amino acid are known as nonsense mutations.
Assertion: An organism with lethal mutation may not even develop beyond the zygote stage.
Reason: All types of gene mutations are lethal.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
Which one of the following pairs is correctly matched with regard to the codon and the amino acid coded by it
UUA - valine
AUG - cysteine
AAA - lysine
CCC - alanine
Assertion : Replication and transcription occur in the nucleus but translation occurs in the cytoplasm.
Reason : mRNA is transferred from the nucleus into the cytoplasm where ribosomes and amino acids are available for protein synthesis.
If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion
If Assertion is true but Reason is false
If both Assertion and Reason are false
Which one of the following pairs of terms/ names mean one and the same thing?
Gene pool - genome
Codon - gene
Cistron - triplet
DNA fingerprinting - DNA profiling
What is true about tRNA?
It binds with an amino acid at it 3' end
It has five double stranded regions
It has a codon at one end which recognizes the anticodon on messenger RNA
It looks like clover leafin the three dimensional structure
All eukaryotic genes contain two kinds of base sequences. Which of the following plays role in protein synthesis ?
Introns
Exons
Electrons
Both (a) and (b)
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