MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 302 Mcqs, each offering curated multiple-choice questions to sharpen your Biology knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
If viral 'DNA' integrates in host cell chromosomes, with no progeny production, process is called |
| A. | Lytic cycle |
| B. | Lysogenic cycle |
| C. | Replicative cycle |
| D. | Translational cycle |
| Answer» C. Replicative cycle | |
| 102. |
The Shine-Dalgarno sequence is |
| A. | trailer sequence |
| B. | a stop codon |
| C. | the reading frame of a gene |
| D. | a short sequence that acts as a ribosomal binding site |
| Answer» E. | |
| 103. |
The role of molecular chaperones is to |
| A. | facilitate binding of ribosomes to mRNA |
| B. | degrade newly synthesized polypeptides that contain inaccurate sequences |
| C. | facilitate binding of RNA polymerase to DNA |
| D. | aid a newly synthesized polypeptide in folding to its proper shape |
| Answer» E. | |
| 104. |
Which of the following three codons translate as serine (Ser)? |
| A. | AGU |
| B. | CGA |
| C. | CAU |
| D. | AUG |
| Answer» B. CGA | |
| 105. |
Proteomics is |
| A. | the study of algal genomes |
| B. | a branch of quantum physics dealing with proteins |
| C. | the study of formation of lipo-protein in animals |
| D. | the study of the entire collection of proteins expressed by an organism |
| Answer» E. | |
| 106. |
Which of the following is used for determining the location of specific genes within the genome? |
| A. | Genomics |
| B. | Annotation |
| C. | Cloning |
| D. | Proteomics |
| Answer» C. Cloning | |
| 107. |
If a cell has acquired new character as a result of integrated prophage, process is called as |
| A. | Lytic cycle |
| B. | Lysogenic cycle |
| C. | Lysogenic conversion |
| D. | Replication |
| Answer» D. Replication | |
| 108. |
The synthesis of mRNA based on a DNA template is called |
| A. | DNA replication |
| B. | transcription |
| C. | translation |
| D. | DNA restriction |
| Answer» C. translation | |
| 109. |
Site of attachment for 'HIV' virus is |
| A. | Acetylcholine receptor |
| B. | CD4 proteins on T lymphocytes |
| C. | Fibroblast receptor |
| D. | Wall receptor |
| Answer» C. Fibroblast receptor | |
| 110. |
A quorum sensing system |
| A. | detects a signal from the external environment |
| B. | senses a compound produced by the bacterium itself |
| C. | consists of a sensor component that phosphorylates a regulatory protein |
| D. | controls the activity of ribosomes directly |
| Answer» C. consists of a sensor component that phosphorylates a regulatory protein | |
| 111. |
Who discovered transposons (jumping genes)? |
| A. | Abelson |
| B. | Harvey |
| C. | McClintock |
| D. | Griffith |
| Answer» D. Griffith | |
| 112. |
What is term used for a bacterial cell that is able to take up naked DNA? |
| A. | Complementary |
| B. | Liable |
| C. | Competent |
| D. | Infected |
| Answer» D. Infected | |
| 113. |
The transposase gene encodes an enzyme that facilitate |
| A. | viral replication within a genome |
| B. | general recombination |
| C. | site-specific integration of transposable elements |
| D. | none of the above |
| Answer» D. none of the above | |
| 114. |
The flow of genetic material in microbial cells usually takes place from |
| A. | RNA through DNA to proteins |
| B. | proteins through RNA to DNA |
| C. | DNA through RNA to proteins |
| D. | none of these |
| Answer» D. none of these | |
| 115. |
Diagnostic DNA probes have been developed for |
| A. | Mycobacterium tuberculosis |
| B. | Hepatitis B virus |
| C. | Human immunodeficiency virus |
| D. | all of the above |
| Answer» E. | |
| 116. |
In DNA sequencing, the primer |
| A. | specifies where the sequence ends |
| B. | specifies where the sequence begins |
| C. | both (a) and (b) |
| D. | generates variety of different sized fragments |
| Answer» C. both (a) and (b) | |
| 117. |
The transducing particles carry only specific portions of the bacterial genome in which of the following transduction? |
| A. | Specialized transduction |
| B. | General transduction |
| C. | Abortive transduction |
| D. | None of these |
| Answer» B. General transduction | |
| 118. |
The function of ribosomes within the cell is |
| A. | to produce ATP |
| B. | to ferment carbohydrates |
| C. | to synthesize proteins |
| D. | all of these |
| Answer» D. all of these | |
| 119. |
Three stop codons, which aids in termination of translation are also known as |
| A. | pause codons |
| B. | nonsense codons |
| C. | missense codons |
| D. | antisense codons |
| Answer» C. missense codons | |
| 120. |
What are the Svedberg values for the subunits of the 70S ribosomes of E. colli? |
| A. | 40S and 30S |
| B. | 50S and 20S |
| C. | 50S and 30S |
| D. | 40S and 20S |
| Answer» D. 40S and 20S | |
| 121. |
What is the direct cause of cell death by diphtheria toxin? |
| A. | Formation of an ion channel in the cell membrane |
| B. | Inactivation of a translational elongation factor |
| C. | Induction of apoptosis |
| D. | None of the above |
| Answer» C. Induction of apoptosis | |
| 122. |
The interaction between the mRNA and tRNA determined the position of amino acid in a polypeptide sequence. This is called the |
| A. | stagerivity |
| B. | Wobble hypothesis |
| C. | promiscuity |
| D. | adaptor hypothesis |
| Answer» E. | |
| 123. |
When composite transposons are formed |
| A. | a small deletion occurs in the transposase gene of an IS element |
| B. | a small deletion occurs in the transposase gene of an IS element and plasmid is integrated |
| C. | an IS element integrates with another IS element with the help of a plasmid |
| D. | two IS elements integrate into a chromosome with only a small distance separating them |
| Answer» E. | |
| 124. |
Which of the following term describes the relationship between a virus and host where no new viral particles are produced and the viral genome is replicated along with host chromosome? |
| A. | Lysogeny |
| B. | Lysis |
| C. | Transformation |
| D. | Conjugation |
| Answer» B. Lysis | |
| 125. |
Which of the following mutation affects only a single nucleotide? |
| A. | Aerial mutation |
| B. | Site mutation |
| C. | Point mutation |
| D. | Regional mutation |
| Answer» D. Regional mutation | |
| 126. |
Within bacterial cells transfer of 'DNA' is carried out through |
| A. | Insertion |
| B. | Programmed rearrangements |
| C. | Conjugations |
| D. | Deletions |
| Answer» C. Conjugations | |
| 127. |
'Poxviruses' replicates in |
| A. | Vacuole |
| B. | Cytoplasm |
| C. | Nucleus |
| D. | Mitochondria |
| Answer» C. Nucleus | |
| 128. |
All viruses replicate in DNA , except |
| A. | Poxviruses |
| B. | HIV |
| C. | HBV |
| D. | HCV |
| Answer» B. HIV | |
| 129. |
Which of these mechanisms for thymine dimers repair lead to mutations? |
| A. | Excision repair |
| B. | Photoreactivation |
| C. | SOS repair |
| D. | Never leads to mutation |
| Answer» D. Never leads to mutation | |
| 130. |
The development of global regulatory systems in prokaryotes |
| A. | determines the exact location of the cell on the globe |
| B. | aids in DNA replication |
| C. | determines the exact location of the replication site |
| D. | regulates many genes under varying environmental conditions |
| Answer» E. | |
| 131. |
Due to which of the following DNA repair mechanisms, one is able to distinguish newly synthesized DNA strands from older one? |
| A. | New strands do not contain cytosine bases |
| B. | New strands are lower in molecular size |
| C. | Old strands are methylated while new strands are not |
| D. | New strands are methylated while old strands are not |
| Answer» D. New strands are methylated while old strands are not | |
| 132. |
Which stop codon has been found to encode selenocysteine? |
| A. | UAA |
| B. | UAG |
| C. | UGA |
| D. | AGA |
| Answer» D. AGA | |
| 133. |
When was the genetic code completed? |
| A. | 1958 |
| B. | 1952 |
| C. | 1966 |
| D. | 1968 |
| Answer» D. 1968 | |
| 134. |
Which phage always carries a small piece of E.coli genome? |
| A. | Lambda |
| B. | Mu |
| C. | T4 |
| D. | T3 |
| Answer» C. T4 | |
| 135. |
Which of the following is a nontranslated sequence located between the transcription and the translation start site? |
| A. | Ending frame |
| B. | Leader sequence |
| C. | Trailer sequence |
| D. | Reading frame |
| Answer» C. Trailer sequence | |
| 136. |
Site in the ribosome from which the tRNA donates amino acids to the growing polypeptide chain is |
| A. | P site |
| B. | O site |
| C. | T site |
| D. | A site |
| Answer» B. O site | |
| 137. |
The final step of gene expression is protein synthesis, which is also known as |
| A. | replication |
| B. | translation |
| C. | transcription |
| D. | none of these |
| Answer» C. transcription | |
| 138. |
The synthesis of DNA by DNA polymerase occurs in the |
| A. | 3' to 5' direction |
| B. | 5' to 5' direction |
| C. | 5' to 3' direction |
| D. | 3' to 3' direction |
| Answer» D. 3' to 3' direction | |
| 139. |
Which binding is inhibited by pactamycin? |
| A. | Aminoacyl-tRNA to the A-site of 30S subunit |
| B. | Initiator-tRNA to 30S/40S initiation complexes |
| C. | Peptidyl t-RNA to the 50S subunit |
| D. | Formation of peptide bond in P site |
| Answer» C. Peptidyl t-RNA to the 50S subunit | |
| 140. |
Negative regulation of protein synthesis is accomplished by |
| A. | allosteric inhibition |
| B. | the binding of RNA polymerase to the promoter |
| C. | the binding of a repressor to the DNA |
| D. | the binding of a repressor to the RNA polymerase |
| Answer» D. the binding of a repressor to the RNA polymerase | |
| 141. |
Which of the following act as the blueprint or template for the process of protein synthesis that takes place on ribosomes? |
| A. | rRNA |
| B. | DNA |
| C. | tRNA |
| D. | mRNA |
| Answer» E. | |
| 142. |
During DNA replication in prokaryotes, synthesis begins on the circular chromosome |
| A. | always at the same place |
| B. | at any stretch of DNA that is high in AT pairs |
| C. | randomly on the chromosome |
| D. | at the promoter |
| Answer» B. at any stretch of DNA that is high in AT pairs | |
| 143. |
Which of the following lacks 3'-5' exonuclease activity? |
| A. | Short fragment of DNA polymerase I |
| B. | Taq DNA polymerase |
| C. | T4 DNA ligase |
| D. | All of the above |
| Answer» E. | |
| 144. |
Site of attachment of 'rabies' virus is |
| A. | Acetylcholine receptor |
| B. | CD4 proteins on T lymphocytes |
| C. | Fibroblast receptor |
| D. | Wall receptor |
| Answer» B. CD4 proteins on T lymphocytes | |
| 145. |
Which of the following bacterial genome was sequenced first? |
| A. | E. coli |
| B. | S. pneumoniae |
| C. | H. influenzae |
| D. | S. thermophilus |
| Answer» D. S. thermophilus | |
| 146. |
The original enzyme(s) used in PCR reaction is/are known as |
| A. | E. coli DNA polymerase |
| B. | E. coli RNA polymerase |
| C. | Taq polymerase |
| D. | all of these |
| Answer» B. E. coli RNA polymerase | |
| 147. |
When one or more base pair are deleted or added in sequence, shifts reading frame on ribosome, called |
| A. | Substitution mutation |
| B. | Missense mutation |
| C. | Nonsense mutation |
| D. | Frameshift mutation |
| Answer» E. | |
| 148. |
All 'RNA' viruses contain single-stranded 'RNA' except |
| A. | Reovirus |
| B. | Retrovirus |
| C. | HIV |
| D. | HBV |
| Answer» B. Retrovirus | |
| 149. |
Pilin is an important protein that forms conjugation tube during process of conjugation, process is named as |
| A. | Tube |
| B. | Pilus |
| C. | Pilin |
| D. | Pilin tube |
| Answer» C. Pilin | |
| 150. |
Transcription of 'RNA' to double-stranded 'DNA' is catalyzed by enzyme |
| A. | Polymerase |
| B. | Transcriptase |
| C. | Reverse Transcriptase |
| D. | Ligase |
| Answer» D. Ligase | |