W.B Civil Service Examination (Main)- 2005
(Optional Papers)
Botany Paper-II
Time Allowed-3 Hours Full Marks-100
If the question 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.
Answer may be given either in English or in Bengali but all answers must be in one and the same language.
Group - A
Answer any three questions
1. (a) Distinguish between polyteny and ployploidy. Where do we find polytene Chromosome ? Give scientific name of a natural polyploid.
(b) What is meant by the check points in cell cycle ? Give a brief outline. What is Go state ?
(c) What are the different conformations of DNA molecule ? What is Okazaki fragment ?
(d) What are the different types of RNA ? Briefly mention their function.
(e) What is nucleosome ? How does it help in packaging DNA in chromosome ? 4 x 5
2. (a) Some species may reproduce sexually at certain times and a sexually at other times. From which of these modes of reproduction would you expect greater differences between an offspring and its parent ? Justify your answer. What is apomixis ?
(b) What is frame-shift mutation ? How can sex-linked lethal mutation be detected ?
(c) Discuss the significance of genetic recombination in the process of evolution. What is Holiday structure ? Name the scientist who first proposed this model.
(d) What is hybride vigour ? Give its genetic explanation and practical application. If the seeds of hybride corn are sown to raise F generation would you expect same vigour in the progeny ?
(e) What is polygenic trait ? Discuss the mode of inheritance of these traits. What is non-mendelian inheritance ? 4 x 5
3. (a) What is the relation between buffer solution and hydrogen ion concentration ? What is the molarity of a solution ?
(b) What is meant by tracer technique ? Briefly discuss its usefulness. What is the difference between fluorescence and phosphores-cence ?
(c) What is protone ? Distinguish between primary, secondary and tertiary structures of protien.
(d) Distinghish between standard deviation and standard error. What is goodness of fit and how can you determine it ?
(e) Under what conditions does Rubisco fix O2 ? What are the products of such fixation ? 4 x 5
4. (a) Inspite of plenty of Nitrogen in atmosphere why the plants can not utilize it directly ? What is biological nitrigen fixation ? What are the microbes responsible for this ? Why all the plants are not capable of fixing nitrogen in this way ?
(b) What is the role of potassium ion in plants ? Mention the criterion for essentiality of essential elements. What is meant by trace element ?
(c) What is Emerson effect ? Discuss its significance.
(d) What is CAM ? Discuss its ecological signititicance.
(e) Distinguish between nucleotide and uncleoside. Why pyrmidine base in RNA is uracil instead of thymine ? 4 x 5
5. (a) Distinguish between C and C-4 plants eiting examples in each case. Which one of these you consider more efficient in productivity and why ?
(b) What is endemism ? Briefly discuss the factors responsible for endemism.
(c) Why the plants growing in desert area are usually thorny and stunted in growth ? Discuss morphological physiological and anatomical adaptation of the Xerophytes.
(d) Distinguish between primary and secondary metabolites. Mention the sources of the following alkatoids indicating botanical name of the plants, family and the places where they grow :
(i) Reserpine (ii) Vinblastin (iii) Strychnin and (iv) Kurchine.
(e) What is the botanical name of cultivated bread wheat and what is its genomic constitution ? Frace its orgin and evolution. 4 x 5
Group-B
Answer any two questions.
6. (a) What is repetitive DNA ? Comment on its function. What is meant by "tandem repeat" ?
(b) What is polymorphism ? How can we delect genetic polymorphism ?
(c) What is C-DNA ? How can you raise C-DNA Library ?
(d) What is gene eloning ? Mention a suitable cloning vector. Comment on the utility of cloning.
(e) What is transgenic plant ? Mention the basic mechanism through which it is produced and the benefit of it. 4 x 5
7. (a) What is stem cell ? Distinguish between totipotence and pluripotency. Why stem cell research is gaining so much improtance at present ?
(b) What are phytohormones ? Give the structure of IAA. Name a gaseous of phytohormones.
(c) What are the cause of dormance and how can a dormant seed be induced to germinate ? How can you ascertain whether a seed is dormant or non-viable ?
(d) Name two high yielding varieties of rice that are cultivated now. What is "Golden Rice" ? Comment on the plant type concept that has been responsible for green revolution in case of rice
(e) What is meant by genetic equilibrium ? Who proposed this concept ? What are the conditions which much be satisfied for maintaining genetic equilibrium ? 4x5
8. (a) What is meant by genetic equilibrium ? Who proposed this concept ? What is the usefulness of "Red Data Book" ?
(b) What are the characteristic features of "Mangrove forest" ? Give example and mention two species of plants growing in such forest.
(c) What is "Biosphere Reserve" ? Cite two examples in India and mention its ecological importance. What is "Green House Effect" ? What are the factors responsible for this Comment on its consequences.
(d) What is "Biomass Energy" ? Discuss the ultimate source of this energy and mode of its utilization. Why the use of biomass energy is strongly advocated now-a-days ? 4 x 3
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