Essential Biochemistry - Regulation Of Gene Expression And Mutation (Section 2)
1
How is gene expression in eukaryotes controlled?
Answer
(B)
Many different ways
2
Which of the following are types of point mutations?
Answer
A
B
3
Which of the following is the combined process of the transcription of a gene into mRNA and its translation into protein?
Answer
(B)
Gene expression
4
Which of the following is a consequence of the deletion of a single nucleotide from the coding strand of a gene?
Answer
(C)
Frame shift mutation
5
Where does the RNA polymerase bind to initiate transcription?
Answer
(C)
Promoter
6
What is the function of beta-galactosidase?
Answer
(A)
Hydrolyzes lactose into glucose and galactose
7
What is the effect of a 'missense mutation'?
Answer
(B)
It changes the amino acid sequence.
8
What happens to the RNA polymerase when the repressor is bound to the operator?
Answer
(B)
It cannot bind to the promoter and transcribe the genes.
9
In the lac operon, what is the role of the 'I' gene?
Answer
(A)
It codes for the repressor protein.
10
What does the term 'operon' refer to?
Answer
(B)
A group of genes that are transcribed together
11
Which of the following mutations would likely have the least severe impact on a protein?
Answer
(C)
Insertion of three nucleotides.
12
In the presence of lactose, what molecule acts as an inducer?
Answer
(C)
Lactose
13
What is the effect of CAP-cAMP binding to the CAP-binding site of the promoter?
Answer
(B)
It stimulates transcription.
14
Which type of mutation results in a change of the amino acid sequence that might be acceptable?
Answer
(C)
Missense mutation
15
What is the role of the repressor protein in the lac operon?
Answer
(B)
It binds to the operator site and blocks transcription.
16
What is the role of the operator in the lac operon?
Answer
(B)
It is the binding site for the repressor protein.
17
Which of the following is the type of gene that is expressed only when a specific positive regulatory substance, i.e., an inducer or activator, is present?
Answer
(A)
Inducible gene
18
In the presence of glucose, how is the lac operon affected?
