MCQOPTIONS
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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.
| 151. |
'retrovirus' and 'influenza' virus replicate in |
| A. | Cytoplasm |
| B. | Nucleases |
| C. | Nucleus |
| D. | Mitochondria |
| Answer» D. Mitochondria | |
| 152. |
Viral DNA replicates, in |
| A. | Cytoplasm |
| B. | Vacuole |
| C. | Nucleus |
| D. | Mitochondria |
| Answer» D. Mitochondria | |
| 153. |
Which of the following is the cause for drug resistance in tuberculosis? |
| A. | Mutation |
| B. | Transduction |
| C. | Transformation |
| D. | Conjugation |
| Answer» B. Transduction | |
| 154. |
If a cell is infected by a virus, calculated time to replicate it is approximately: |
| A. | 12 hours |
| B. | 10 hours |
| C. | 8 hours |
| D. | 4 hours |
| Answer» C. 8 hours | |
| 155. |
DNA replication rates in prokaryotes are approximately of the order of |
| A. | 10 bases per second |
| B. | 1,00 bases per second |
| C. | 1,000 bases per second |
| D. | 10,000 bases per second |
| Answer» D. 10,000 bases per second | |
| 156. |
Penicillin resistance in staphylococci is acquired due to |
| A. | conjugation |
| B. | mutation |
| C. | transformation |
| D. | transduction |
| Answer» E. | |
| 157. |
Which eukaryotic RNA polymerase makes tRNA's? |
| A. | RNA polymerase 1 |
| B. | RNA polymerase 2 |
| C. | RNA polymerase 3 |
| D. | Any of these |
| Answer» D. Any of these | |
| 158. |
What information can be generated by interrupted mating experiments? |
| A. | Levels of DNA homology |
| B. | Bacterial genome maps |
| C. | DNA nucleotide sequences |
| D. | Proteomics of the bacteria |
| Answer» C. DNA nucleotide sequences | |
| 159. |
During which of the following process a new copy of a DNA molecule is precisely synthesized? |
| A. | Trasformation |
| B. | Transcription |
| C. | Translation |
| D. | Replication |
| Answer» E. | |
| 160. |
In E.coli, which enzyme synthesizes the RNA primer for Okazaki fragments? |
| A. | DnaA |
| B. | DnaC |
| C. | DnaG |
| D. | all of these |
| Answer» D. all of these | |
| 161. |
Which of the following possesses both 5'-3' and 3'-5' exonuclease activity? |
| A. | Kornberg enzyme |
| B. | DNA polymerase III |
| C. | Taq DNA polymerase |
| D. | None of these |
| Answer» B. DNA polymerase III | |
| 162. |
The replication of chromosomes by eukaryotes occurs in a relatively short period of time because |
| A. | the eukaryotes have more amount of DNA for replication |
| B. | the eukaryotic replication machinery is 1000 times faster than the prokaryotes |
| C. | each chromosome contains multiple replicons |
| D. | eukaryotic DNA is always single stranded |
| Answer» D. eukaryotic DNA is always single stranded | |
| 163. |
Both strands of DNA serve as templates concurrently in |
| A. | replication |
| B. | excision repair |
| C. | mismatch repair |
| D. | none of these |
| Answer» B. excision repair | |
| 164. |
Why Deinococcus radiodurans is able to survive massive exposure to radiation? |
| A. | Because it produces a thick shell which acts as a shield from the radiation |
| B. | Because it has unique DNA repair mechanisms |
| C. | Because its cellwall contains radioactive elements |
| D. | Because it has many copies of genes encoding DNA repair |
| Answer» E. | |
| 165. |
Which of the following repairs nicked DNA by forming a phosphodiester bond between adjacent nucleotides? |
| A. | Helicase |
| B. | DNA gyrase |
| C. | Topoisomerases |
| D. | DNA ligase |
| Answer» E. | |
| 166. |
Proofreading activity to maintain the fidelity of DNA synthesis |
| A. | occurs after the synthesis has been completed |
| B. | is a function of the 3'-5' exonuclease activity of the DNA polymerases |
| C. | requires the presence of an enzyme separate from the DNA polymerases |
| D. | occurs in prokaryotes but not eukaryotes |
| Answer» C. requires the presence of an enzyme separate from the DNA polymerases | |
| 167. |
The enzyme that catalyzes the synthesis of DNA is called |
| A. | DNA polymerase |
| B. | DNA gyrase |
| C. | DNA ligase |
| D. | helicase |
| Answer» B. DNA gyrase | |
| 168. |
Studies of similarities and differences among the genomes of multiple organisms is carried out in |
| A. | comparative genomics |
| B. | proteomics |
| C. | functional genomics |
| D. | structural genomics |
| Answer» B. proteomics | |
| 169. |
Which of the following is the study of the molecular organization of genomes, their information content and the gene products they encode? |
| A. | Genetics |
| B. | Ergonomics |
| C. | Genomics |
| D. | Bioinformatics |
| Answer» D. Bioinformatics | |
| 170. |
Which type of genomics studies the transcripts and proteins expressed by a genome? |
| A. | Comparative genomics |
| B. | Structural genomics |
| C. | Proteo genomics |
| D. | Functional genomics |
| Answer» E. | |
| 171. |
Which of the following organisms has the smallest genome? |
| A. | H. influenzae |
| B. | M. genitalium |
| C. | M. tuberculosis |
| D. | None of these |
| Answer» C. M. tuberculosis | |
| 172. |
The word, used for the small solid supports onto which are spotted hundreds of thousands of tiny drops of DNA that can be used to screen gene expression, is |
| A. | southern blot |
| B. | cloning library |
| C. | DNA microarrays |
| D. | northern blot |
| Answer» D. northern blot | |
| 173. |
DNA gyrase is inhibited by |
| A. | tetracycline |
| B. | nalidixic acid |
| C. | both (a) and (b) |
| D. | cephalosporin |
| Answer» C. both (a) and (b) | |
| 174. |
Genetic variations are |
| A. | temporary |
| B. | influenced by the environment |
| C. | stable |
| D. | not heritable |
| Answer» D. not heritable | |
| 175. |
Polymerase chain reaction basically consists of |
| A. | two steps |
| B. | three steps |
| C. | four steps |
| D. | five steps |
| Answer» C. four steps | |
| 176. |
What is the range of minimum set of genes required for life? |
| A. | 50-100 genes |
| B. | 250-350 genes |
| C. | 1000-1500 genes |
| D. | 1500-2000 genes |
| Answer» C. 1000-1500 genes | |
| 177. |
A particular family of viruses that is diploid, known as |
| A. | Reovirus |
| B. | Retrovirus |
| C. | HIV |
| D. | Poliovirus |
| Answer» C. HIV | |
| 178. |
The sigma factor |
| A. | is responsible for recognizing the termination sequence |
| B. | provides the catalytic function of cleaving off pyrophosphates during mRNA synthesis |
| C. | recognizes the promotor |
| D. | accomplishes DNA restriction |
| Answer» D. accomplishes DNA restriction | |
| 179. |
'Parvoviruses' composed of |
| A. | double-stranded DNA |
| B. | RNA |
| C. | single-stranded DNA |
| D. | double-stranded RNA |
| Answer» D. double-stranded RNA | |
| 180. |
Which of the following molecule catalyzes the transpeptidation reaction? |
| A. | RNA polymerase |
| B. | Peptidyl transferase |
| C. | DNA ligase |
| D. | DNA polymerase |
| Answer» C. DNA ligase | |
| 181. |
A minor change in sequence of 'base pairs' is called as |
| A. | Alternation |
| B. | Defects |
| C. | Mutations |
| D. | Deletions |
| Answer» D. Deletions | |
| 182. |
What is the action of tetracycline in prokaryotes? |
| A. | It blocks translocation reaction on ribosomes |
| B. | It blocks peptidyl transferase reaction on ribosomes |
| C. | It blocks the binding of amino-acyl tRNA to the A site of ribosomes |
| D. | Not known with certainity |
| Answer» D. Not known with certainity | |
| 183. |
Which of the following(s) is/are steps in excision repair mechanisms? |
| A. | Excision |
| B. | Incision |
| C. | Ligation |
| D. | All of these |
| Answer» E. | |
| 184. |
The DNA that actually codes for a protein's primary structure in eukaryotes is |
| A. | the entire gene |
| B. | portions of the gene called introns |
| C. | portions of the gene called exons |
| D. | the promoter |
| Answer» D. the promoter | |
| 185. |
The chromosome of almost all bacteria is in the shape of |
| A. | an open circle |
| B. | helix |
| C. | a closed circle |
| D. | a linear chromosome |
| Answer» D. a linear chromosome | |
| 186. |
Which of the following mutations arise without exposure to external agents? |
| A. | Spontaneous mutations |
| B. | Analogous mutations |
| C. | Induced mutations |
| D. | None of these |
| Answer» B. Analogous mutations | |
| 187. |
Which of the following enzyme is used for synthesis of RNA under the direction of DNA? |
| A. | RNA polymerase |
| B. | DNA ligase |
| C. | DNA polymerase |
| D. | RNA ligase |
| Answer» B. DNA ligase | |
| 188. |
The plasmid which makes the host more pathogenic is |
| A. | F factors |
| B. | Metabolic plasmid |
| C. | Virulence plasmid |
| D. | None of these |
| Answer» D. None of these | |
| 189. |
To which of the following adenine always binds? |
| A. | Guanine |
| B. | Cytosine |
| C. | Thymine |
| D. | None of these |
| Answer» D. None of these | |
| 190. |
Which of the following statements on replication in E.coli is correct? |
| A. | It occurs in a unidirectional manner |
| B. | It occurs in bidirectional manner |
| C. | Always uses T7 DNA polymerase when infected by T7 phage |
| D. | Occurs only when λ phase has infected E. coli |
| Answer» C. Always uses T7 DNA polymerase when infected by T7 phage | |
| 191. |
The promoter on an expression vector used to overproduce proteins in bacteria is |
| A. | a bacterial promoter |
| B. | expressed both in bacteria and mammalian cells |
| C. | not a regulated promoter |
| D. | the natural promoter of the gene being cloned |
| Answer» B. expressed both in bacteria and mammalian cells | |
| 192. |
A nonsense mutation may result into |
| A. | an abnormal elongation of a polypeptide |
| B. | a large deletion within the reading frame of a gene |
| C. | a premature termination of the synthesis of a polypeptide |
| D. | modification of mRNA |
| Answer» D. modification of mRNA | |
| 193. |
Which is not an essential part of a two-component phosphorelay system? |
| A. | Response regulator |
| B. | Sensor kinase |
| C. | Autoinducer |
| D. | None of these |
| Answer» D. None of these | |
| 194. |
Which of the following enzymes unwind short stretches of DNA helix immediately ahead of a replication fork? |
| A. | DNA polymerases |
| B. | Helicases |
| C. | Single-stranded binding proteins |
| D. | Topoisomerases |
| Answer» C. Single-stranded binding proteins | |
| 195. |
'replicative cycle' of most of viruses is completed in |
| A. | Cytoplasm |
| B. | Nucleases |
| C. | Nucleus |
| D. | Mitochondria |
| Answer» B. Nucleases | |
| 196. |
Transfer of 'DNA' from one bacterial cell to another is carried out by |
| A. | Conjugation |
| B. | Transduction |
| C. | Transformation |
| D. | All of above |
| Answer» E. | |
| 197. |
Bacteria composed single chromosomes, having single copy of gene, known as |
| A. | Diploid |
| B. | Haploid |
| C. | Polyploidy |
| D. | Monoploid |
| Answer» C. Polyploidy | |
| 198. |
In the extracellular medium, DNA-degrading enzymes would likely be to prevent transfer of DNA by |
| A. | conjugal transfer by a self-transmissible plasmid |
| B. | generalized phage transduction |
| C. | natural transformation |
| D. | none of the above |
| Answer» D. none of the above | |
| 199. |
Transfer of 'DNA' from one cell to another, is known as |
| A. | Transformation |
| B. | Transduction |
| C. | Conjugations |
| D. | Mating |
| Answer» B. Transduction | |
| 200. |
What was the first bacterial genome to be sequenced and made public? |
| A. | Bacillus subtilis |
| B. | Escherichia coli |
| C. | Haemophilus influenzae |
| D. | No bacterial genome has been sequenced yet |
| Answer» D. No bacterial genome has been sequenced yet | |