In eukaryotes the gene expression is regulated at:
A. Transcriptional level
B. Processing level
C. Transport of mRNA from nucleus to the cytoplasm
D. Translational level
(1) A, C
(2) A, B, C, D
(3) B, C, D
(4) A, B, C
In prokaryotes, gene regulation occurs at the level of:
(1) Transcription
(2) Translation
(3) Post transcription
(4) Post translation
Characteristic(s) of most DNA is / are:
A. A pairs with T by 2 hydrogen bonds.
B. Antipolarity of complementary chains
C. 20Aº diameter
D. 10 bps/turn
(1) A, C
(2) A, B, C, D
(3) B, C, D
(4) A, B, C
A. DNA polymorphism plays important role in evolution and speciation.
B. 99.9% nucleotides bases are exactly same in all people
C. Chromosome 1 has the fewest genes (23) and Y-chromosomes has most genes (2968)
D. BAC and YAC have been used in Human Genome Project.
(1) All correct
(2) All incorrect
(3) A, B, D are correct
(4) B, C, D are correct
Which one(s) is / are correct?
A. In prokaryotes, a single type of RNA polymerase can transcribe mRNA, tRNA and rRNA.
B. In eukaryotes, RNA polymerase I transcribes rRNAs (28S, 18S, and 5.8S), whereas RNA polymerase III is responsible for the transcription of tRNA, 5srRNA, and snRNAs.
C. RNA pol II transcribes hnRNA in eukaryotes.
D. Ribosomal large subunit has p and A-sites.
(1) A, C
(2) A, B, C, D
(3) B, C, D
(4) A, B, D
Go through the following diagram of Nucleosome (structural unit of chromatin). Identify its componential parts indicated by A, B and C:
A | B | C | |
(1) | RNA | Non histone | Histone |
(2) | DNA | H1 histone | Histone Octamer |
(3) | RNA | Histone Octamer |
H1 histone |
(4) | DNA | Non histone | Histone |
Following is the schematic structure of transcription unit having some important components indicated by A, B, C, D and E. In which of four option the components are identified correctly:
|
A |
B |
C |
D |
E |
(1) |
Terminator |
Transcription start site |
Promoter |
Template strand |
Coding strand |
(2) |
Promoter |
Transcription start site |
Terminator |
Coding strand |
Template strand |
(3) |
Promoter |
Transcription start site |
Terminator |
Template strand |
Coding strand |
(4) |
Terminator |
Transcription start site |
Promoter |
Coding strand |
Template strand |
The fact that the genetic code is almost universal in living organisms is considered to be evidence that all organisms:
(1) Are evolutionarily related
(2) Are genetically identical
(3) Have the same sequence of anticodons
(4) None of the above
In the following diagram of the lac operon, an operon for inducible enzymes, identify components and enzymes:
|
X |
Y |
E1 |
E2 |
E3 |
(1) |
Repressor protein |
Inducer (lactose) |
â-Galactosidase |
Permease |
Transacetylase |
(2) |
Inducer (lactose) |
Repressor protein |
â-Galactosidase |
Permease |
Transacetylase |
(3) |
Repressor protein |
Inducer (lactose) |
â-Galactosidase |
Transacetylase |
Permease |
(4) |
Repressor protein |
Inducer (lactose) |
Permease |
Transacetylase |
â-Galactosidase |
Alfred Hershey and Martha Chase made a big contribution in proving DNA role as the hereditary molecule. The experiment is shown in the diagram. A and C are the presence or absence of radioactivity detected in cells B and D are the presence or absence of radioactivity detected in supernatants cells. Identify A, B, C and D:
(a) A - No Radioactivity (35S) detected in cells; B - Radioactivity (32P) detected in supernatant; C - Radioactivity (35S) detected in cells; D - No Radioactivity in supernatant
(b) A- Radioactivity (35S) detected in cells; B - No Radioactivity (35S) detected in supernatant; C - Radioactivity (32P) detected in cells; D - No Radioactivity in supernatant
(c) A - No Radioactivity (35S) detected in cells; B - Radioactivity (35S) detected in supernatant; C - Radioactivity (32P) detected in cells; D - No Radioactivity in supernatant
(d) A - No Radioactivity (35S) detected in cells; B - Radioactivity (35S) detected in supernatant; C - No Radioactivity (32P) detected in cells; D - Radioactivity in supernatant