4- A point mutation results from
Anonymous Quiz
50%
Substitution of a base
0%
Insertion of a base
6%
Deletion of a base
44%
All of these
5- Substitution of a base can result in a
Anonymous Quiz
8%
Silent mutation
8%
Missense mutation
0%
Nonsense mutation
85%
All of these
6- A silent mutation is most likely to result from
Anonymous Quiz
8%
Substitution of the first base of a codon
83%
Substitution of the third base of a codon
8%
Conversion of a nonsense codon into a sense codon
0%
Conversion of a sense codon into a nonsense codon
7- The effect of a missense mutation can be
Anonymous Quiz
0%
Acceptable
20%
Partially acceptable
7%
Unacceptable
73%
All of these
8- Amino acid sequence of the encoded protein isn't changed in
Anonymous Quiz
42%
Silent mutation
0%
Acceptable missense mutation
42%
Both A and B
17%
Non of these
9- Hemoglobin S is an example of a /an
Anonymous Quiz
0%
Silent mutation
17%
Acceptable missense mutation
25%
Unacceptable missense mutation
58%
Partially acceptable missense mutation
10- If the codon UAC on mRNA changes into UAG as a result of a base Substitution in DNA, it will result in
Anonymous Quiz
17%
Silent mutation
25%
Acceptable missense mutation
58%
Nonsense mutation
0%
Frameshift mutation
11- Insertion of a base in a gene can cause
Anonymous Quiz
0%
Change in reading frame
0%
Garbled Amino acid sequence in the encoded protein
0%
Premature termination of translation
100%
All of these
12- A frameshift mutation changes the reading frame because the genetic code
Anonymous Quiz
0%
Is degenerate
27%
Is overlapping
64%
Has no punctuations
9%
Is universal
13- From DNA the genetic message is transcribed into this compound :
Anonymous Quiz
25%
Protein
67%
mRNA
8%
tRNA
0%
rRNA
14- In the following partial sequence of mRNA, a mutation of the template DNA results in a change in codon 91 to UAA the type of mutation is
Anonymous Quiz
33%
Missense
17%
Silent
50%
Nonsense
0%
Frameshift
1- In the process of transcription in bacterial cells
Anonymous Quiz
0%
Intiation requires rho protein
7%
RNA polymerase incorporates methylated bases in correct sequence
93%
Both sigma unit and core enzymes of RNA polymerase are required for accurate promotor site binding
0%
Primase is necessary for intiation
2- The correct statement concerning RNA and DNA polymerase is
Anonymous Quiz
9%
RNA polymerase use nucleoside diphosphate
0%
RNA polymerase require primers and add bases at 5' end of the growing polynucleotide chain
27%
DNA polymerase can add nucleotides at both ends of the Chain
64%
All RNA and DNA polymerases can add nucleotides only at the 3' end of growing polynucleotide chain
3- Termination of the synthesis of the RNA molecule is signalled by a sequence in the template strand of the DNA molecule, a signal that is recognized by a termination protein, the
Anonymous Quiz
83%
Rho factor
8%
ᓂ factor
8%
δ factor
0%
ε factor
4- The mechanism of synthesis of DNA and RNA are similar in all the following ways except
Anonymous Quiz
0%
They involve release of pyrophosphate from each nucleotide added
0%
They require activated nucleotide precursor and Mg +2
0%
The direction of synthesis is 5'→ 3'
100%
They require a primer
5- A mRNA of eukaryotes can code for
Anonymous Quiz
77%
Only one polypeptide
8%
Two polypeptide
8%
Three polypeptide
8%
Five polypeptide
6- mRNA of prokaryotes can code for
Anonymous Quiz
77%
More than one polypeptide
15%
Only one polypeptide
8%
Many exons and introns
0%
Introns only
7- Reverse transcriptase is capable of synthesising
Anonymous Quiz
86%
RNA → DNA
14%
DNA → RNA
0%
RNA → RNA
0%
DNA → DNA
8- The intiation site for transcription is recognized by
Anonymous Quiz
0%
Alfa subunit of DNA - dependent RNA polymerase
8%
Beta subunit of DNA - dependent RNA polymerase
83%
Sigma factor
8%
Rho factor
11- In mammals, synthesis of mRNA is catalysed by
Anonymous Quiz
8%
RNA polymerase 1
85%
RNA polymerase 2
8%
RNA polymerase 3
0%
RNA polymerase 4