biology
chemistry
physics
miscellaneous
biology mcqs
chemistry mcqs
physics mcqs

Start typing to see results.

Subjects

biology
chemistry
physics
miscellaneous
biology mcqs
chemistry mcqs
physics mcqs

miscellaneous

coding
- Mastering Clean Code: Essential Tips for Every Developer
reactjs notes series

Molecular Basis of Inheritance: MCQ Test

Test your comprehensive knowledge of DNA structure, replication, transcription, genetic code, translation, gene regulation, the Human Genome Project, and DNA fingerprinting with these challenging multiple-choice questions.

Test Your Knowledge

Showing questions 81 - 100 of 169

81. What is the primary role of mRNA in protein synthesis?

Bringing amino acids
Reading the genetic code
Providing the template
Catalyzing peptide bond formation

The mRNA provides the template [52].

82. What is the primary role of tRNA in protein synthesis?

Providing the template
Bringing amino acids and reading the genetic code
Playing structural and catalytic role
Regulating gene expression

tRNA brings amino acids and reads the genetic code [53].

83. What is the primary role of rRNA during translation?

Providing the template
Bringing amino acids
Playing structural and catalytic role
Regulating gene expression

rRNAs play structural and catalytic role during translation [53].

84. In bacteria, how many DNA-dependent RNA polymerases are there to catalyse transcription of all types of RNA?

One
Two
Three
Four

There is single DNA-dependent RNA polymerase that catalyses transcription of all types of RNA in bacteria [53].

85. What factors transiently associate with bacterial RNA polymerase to initiate and terminate transcription, respectively?

Sigma (σ) factor and Rho (ρ) factor
Alpha (α) factor and Beta (β) factor
Enhancer and Silencer
Promoter and Terminator

The RNA polymerase is only capable of catalysing the process of elongation. It associates transiently with initiation-factor (σ) and termination-factor (ρ) to initiate and terminate the transcription, respectively [54].

86. Why can transcription and translation be coupled in bacteria?

Because mRNA requires processing
Because there is separation of cytosol and nucleus
Because mRNA does not require processing and there is no separation of cytosol and nucleus
Because ribosomes are absent

In bacteria, since the mRNA does not require any processing to become active, and also since transcription and translation take place in the same compartment (there is no separation of cytosol and nucleus in bacteria), many times the translation can begin much before the mRNA is fully transcribed. Consequently, the transcription and translation can be coupled in bacteria [54, 55].

87. In eukaryotes, how many RNA polymerases are found in the nucleus, and what is their clear division of labour?

One; transcribes all RNAs.
Two; one for mRNA, one for tRNA/rRNA.
Three; RNA polymerase I for rRNAs, RNA polymerase III for tRNA/5srRNA/snRNAs, RNA polymerase II for hnRNA.
Four; for different genes.

There are at least three RNA polymerases in the nucleus... The RNA polymerase I transcribes rRNAs, whereas the RNA polymerase III is responsible for transcription of tRNA, 5srRNA, and snRNAs. The RNA polymerase II transcribes precursor of mRNA, the heterogeneous nuclear RNA (hnRNA) [55, 56].

88. What additional processing steps does hnRNA undergo in eukaryotes to become functional mRNA?

Splicing
Capping
Tailing
All of the above

The primary transcripts contain both the exons and the introns and are non-functional. Hence, it is subjected to a process called splicing... hnRNA undergoes additional processing called as capping and tailing [56].

89. What unusual nucleotide is added to the 5'-end of hnRNA during capping?

Methyl guanosine triphosphate
Adenylate residues
Uracil triphosphate
Cytosine triphosphate

In capping an unusual nucleotide (methyl guanosine triphosphate) is added to the 5'-end of hnRNA [56].

90. What residues are added at the 3'-end of hnRNA during tailing, and in what manner?

Methyl guanosine triphosphate in a template-dependent manner
Adenylate residues (200-300) in a template-independent manner
Uracil residues in a template-dependent manner
Cytosine residues in a template-independent manner

In tailing, adenylate residues (200-300) are added at 3'-end in a template independent manner [56].

91. The presence of introns and the process of splicing in eukaryotes are reminiscent of what?

Dominance of DNA world
Simplicity of genome
Antiquity and dominance of RNA-world
Recent evolutionary changes

The split-gene arrangements represent probably an ancient feature of the genome. The presence of introns is reminiscent of antiquity, and the process of splicing represents the dominance of RNA-world [57].

92. Why was a genetic code proposed?

To explain DNA replication
To explain RNA transcription
To direct the sequence of amino acids during protein synthesis
To understand mutations

There existed ample evidences... to support the notion that change in nucleic acids (genetic material) were responsible for change in amino acids in proteins. This led to the proposition of a genetic code that could direct the sequence of amino acids during synthesis of proteins [58, 59].

93. Who proposed that the genetic code should be made up of three nucleotides (a triplet code) to code for all 20 amino acids?

James Watson
Francis Crick
George Gamow
Marshall Nirenberg

It was George Gamow, a physicist, who argued that since there are only 4 bases and if they have to code for 20 amino acids, the code should constitute a combination of bases. He suggested that in order to code for all the 20 amino acids, the code should be made up of three nucleotides [59, 60].

94. If the code is a triplet and there are 4 bases, how many codons can be generated?

A permutation combination of 4^3 (4 × 4 × 4) would generate 64 codons [60].

95. Whose chemical method was instrumental in synthesising RNA molecules with defined combinations of bases (homopolymers and copolymers) to decipher the genetic code?

Marshall Nirenberg
Severo Ochoa
Har Gobind Khorana
George Gamow

The chemical method developed by Har Gobind Khorana was instrumental in synthesising RNA molecules with defined combinations of bases (homopolymers and copolymers) [61].

96. Whose cell-free system for protein synthesis finally helped the genetic code to be deciphered?

Marshall Nirenberg
Severo Ochoa
Har Gobind Khorana
George Gamow

Marshall Nirenberg’s cell-free system for protein synthesis finally helped the code to be deciphered [61].

97. Which enzyme, also known as polynucleotide phosphorylase, was helpful in polymerising RNA with defined sequences in a template independent manner?

DNA polymerase
RNA polymerase
Severo Ochoa enzyme
DNA ligase

Severo Ochoa enzyme (polynucleotide phosphorylase) was also helpful in polymerising RNA with defined sequences in a template independent manner [61].

98. How many codons code for amino acids, and how many function as stop codons?

64 code for amino acids, 0 stop codons
20 code for amino acids, 3 stop codons
61 code for amino acids, 3 stop codons
60 code for amino acids, 4 stop codons

61 codons code for amino acids and 3 codons do not code for any amino acids, hence they function as stop codons [62].

99. What does it mean that some amino acids are coded by more than one codon?

The code is ambiguous
The code is redundant
The code is degenerate
The code is universal

Some amino acids are coded by more than one codon, hence the code is degenerate [62].

100. How is the codon read in mRNA?

With punctuations
In a continuous fashion without punctuations
Randomly
Only at specific sites

The codon is read in mRNA in a contiguous fashion. There are no punctuations [62].

1 ... 4 5 6 ... 9

Genetics: Principles of Inheritance and Variation MCQ Test

Evolution: MCQ Test

biology

class 11
class 12

chemistry

class 12

physics

miscellaneous

coding
- Mastering Clean Code: Essential Tips for Every Developer
reactjs notes series

biology mcqs

class 11
class 12