W.B Civil Service Examination (Main)- 2010
(Optional Papers)
Botany Paper-II
Time Allowed-3 Hours Full Marks-100
If the questions attempted are in excess of the prescribed number, only the questions attempted first up to the prescribed number shall be valued and the remaining ones ignored.
Answers may be written either in English or in Bengali but all answers must be in one and the same language.
Group - A
Answer any three questions
1. Answer any five of the following :
(a) What is the full form of RuBisCo ? Write down the dual role and biochemical reactions catalyzed by this enzyme.
(b) Elucidate in brief the process of phloem loading in plants.
(c) What is plasmolysis ? Draw a plant cell showing incipient plasmolysis. What happens when a slightly plasmolysed cell is immersed in a hypotonic solution ?
(d) What type of plant exhibit ' Kranz anatomy ' ? How this anatomical feature helps in efficient carbon fixation ?
(e) What is RQ ? How does it vary according to the nature of respiratory substrate ? Can RQ values be zero ?
(f) Write down the structure of a naturally occurring auxim. What is apical dominance ? Name a plant hormone that antagonise this effect. 4x5
2. Answer any five of the following :
(a) What is an ecotype ? How new ecotypes are generated in a particular place ?
(b) What are greenhouse gases ? How these gases are associated with global warming ?
(c) Describe the successional stages of plants in a hydrosere.
(d) What is meant by plant indicators ? Briefly discuss different types of plant indicators with examples.
(e) Explain in-situ and ex-situ strategies in connection to conservation of biodiversity,
(f) Discuss the processes of evolution of plant community in a particular area. 4x5
3. Write short notes on any five of the following :
(a) Nonsense mutation.
(b) Properties of genetic code.
(c) Central dogma.
(d) Polymerase chain reaction (PCR).
(e) Nucleotide and Nucleoside.
(f) Non-genetic RNA. 4x5
4. Answer any five of the following :
(a) Give the scientific names and families of the plant yielding (i) Reserpine, (ii) Vinblastin, (iii) Azadirachtin, (iv) Atropine.
(b) Write down the medicinal importance of (i) Cinchona succirubra, (ii) Digitalis purpurea.
(c) Write down the scientific names and respective families of two oil-yielding plants. Mention the parts from which the oil is obtained.
(d) Refer the following plants to their respective families and mention their useful parts and atleast one use of each : (i) Tectona grandis. (ii) Saccharum officinatum.
(e) Which is the main fibre yielding plants cultivated in West Bengal ? Give an account of cultivation of these plants and state the scientific name of ihis plant.
(f) Slate the commercial use of sal and tea. Mention their scientific names and respective families. 4x5
5. Answer any five of the following :
(a) Distinguish between coenzymes and cefaclors.
(b) What is meant by dextro-rotatory compound ? What are epimers ? Explain with examples.
(c) Why amino acids are called amphoteric compounds ? Write down the structure of an amino acid having an aromatic side chain.
(d) What are fatty acids ? Distinguish between fats and oils. What is saponification ?
(e) Write down the importance of leghemoglobin and heterocysts in nitrogen fixation.
(f) Give an account of genomics and proteomics. 4x5
Group-B
Answer any two questions.
6. Answer any four of the following :
(a) What are carotenoids ? State the biological significance of carotenoids in plants. Name a water soluble plant pigment.
(b) Name the organalles associated with photorespiration. Is the process totally wasteful to plants ? — explain.
(c) What is the end product of EMP pathway ? Mention only the steps in this pathway where ATP is formed.
(d) Name a non-indole non-nitrogenous plant hormone. Explain the role of this hormone in germination.
(e) What do you mean by the term 'antitranspirant' ? What role does it play in agriculture ? Name a chemical that is commonly used as antitranspirant. 5x4
7. Answer any four of the following :
(a) With labelled sketches describe the structure of a mitotic chromosome.
(b) What are check points ? State the different stages of check points in a cell cycle.
(c) What is apoptosis ? How does it differ from necrosis ?
(d) What is polyploidy ? How can polyploidy be induced in plants ? Which chemical is very commonly used to induce polyploidy ?
(e) A cross was made between purple leaf (pi), glossy seedling (gl) dwarf variety (t) and wild type. Ft plants were test crossed and the following proportions were obtained when a sample of 1000 plants were counted.
Wild type (+++) 475
pl gl t 469
p + + 8
+ gl t 7
pi + t 18
+ gl + 23
+ + t 0
pl gl + 0
Determine the order of 3 genes and prepare a chromosome map. 5x4
8. Answer any fodr of the following :
(a) What kine of soil is called 'physiologically dry' ? Name the particular type of plants grown in these soil. Mention the morphological adaptation noted among these plants.
(b) What is Michaelis constant ? How it can be determined by Linewaever Burk Plot ?
(c) Define the term biodiversity. What do you mean by hotspots on biodiversity. Name any two hotspots of India.
(d) What are fatty acids ? Schematically represent the oxidation of a long chain fatty acid.
(e) What is meant by photolysis? Explain briefly the S-state model associated with it. 5x4
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