BOTANY — HONOURS
(Cell and Molecular Biology)
Full Marks: 50
The figures in the margin indicate full marks.
Candidates are required to give their answers in their own words
as far as practicable.
- Answer any five questions from the following : 2×5
(a) State the central dogma of living organisms.
(b) Comment on the importance of nuclear lamina.
(c) Why does DNA replication go from 5′ to 3′?
(d) What are riboswitches? Give one example.
(e) What happens when a cell reaches G0 stage?
(f) Name one thermostable enzyme used for DNA amplification. Mention its source.
(g) Is there a difference between oncogene and tumor suppressor gene?
(h) Name the histone proteins associated with nucleosome.
- Answer any two questions from the following :
(a) Write a brief essay about application of PCR technology in biotechnology. 5
(b) Discuss the role of telomerase in eukaryotic DNA replication and mention its importance. 4+1
(c) Enumerate the properties of genetic code mentioning the exceptions, if any. 5
(d) How does the initiation of translation occur in prokaryotes? 5
- Answer any three questions from the following :
(a) State the events occur during the G1 – S and G2 – M checkpoints in yeast cell cycle. Describe
the role of MPF during cell-cycle progression. 6+4
(b) What is an operon? Describe the structure of lac-operon. Discuss with diagrams the negative
control of lac-operon. 2+3+5
(c) Describe briefly about the events that led to transition from RNA to DNA world. What is
endosymbiosis? How endosymbiotic theory helps to explain the origin of eukaryotic cell?
(d) What are the structural differences between hnRNA and mRNA? What is spliceosome?
Describe the prerequisite condition for DNA replication in prokaryotes. 2+2+6
(e) What is cancer? Mention the different stages of cancer. What are the probable causes of
cancer? Mention the role of ‘Ras’ gene in cancer. 2+2+4+2
Botany – Botany
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