W.B Civil Service Examination (Main)- 2009
(Optional Papers)
Botany Paper-II
Time Allowed-3 Hours Full Marks-100
Group - A
Answer any three questions
1. Attempt any five questions.
(a) Distinguish between chiasma and crossing over; synaptonemal complex and synapsis.
(b) Why is genetic code said to be degenarate ? How can you prove that genetic code is universal ?
(c) Distinguish among the following: Origin of replication, replication bubble and replication fork.
(d) What are differences and similarities in the genome organization of mt DNA in human and plants ?
(e) What types of gametes would be expected and in what proportions, from an organism that is monosomic for a single chromosome ?
(f) Several different species of rhododendren exist and they have the following numbers of somatic chromosomes :
26, 39, 52, 78, 104 and 156.
(i) What process might produce this series of species with varying chromosome numbers ?
(ii) What would be the basic monoploid number of chromosome ?
(iii) How many sets of chromosomes are present in the species with 78 and 156 chromosome ? 4x5
2. Attempt any five questions.
(a) What are the five major groups of plant hormones ? Mention their sites of biosynthesis and effects.
(b) What is the overall reaction, or equation, for respiration, and what is the main function, of this process ?
(c) What are the principal pigments involved in photosynthesis, and why are leaves green ?
(d) In what ways do C4 plants have the advantage over C3 plants ? Give examples of C4 & C3 plants.
(e) What are the main products of the carbon-fixation reactions of photosynthesis; and why is the name "dark reactions" misleading of this series of reactions ?
(f) What is chemiosmotic coupling ? "Two distinct events take place in chemiosmotic coupling" -what are those events ? 4 x 5
3. Attempt any five questions.
(a) State the reasons for "Green house" effect.
(b) Define biodiversity. How can aforestation protect biodiversity ?
(c) How does plant community change over time ?
(d) Define ecosystem, population and community.
(e) What do you mean by ephemeral plants ? Give suitable examples.
(f) How do plants,defend themselves against herbivores and pathogens ? 4 x 5
4. Attempt any Jive questions.
(a) Give the scientific names and families of two (i) timber yielding plants, and (ii) two medicinally important plant.
(b) Give suitable examples of two oil yielding plants (one each from rnonocot and dicot). Mention their scientific name and family.
(c) Mention the scientific name of the plants cited below and the plant part that is of economic importance. (i) Jute (ii) Tea (iii) Curcumin (iv) Coconut.
(d) State the medicinal uses of sarpagandha, ginger, chirata and Belladona with reference to chemical class of their active principle.
(e) What are the adaptations found in xerophytes ?
(f) Although many medicinal drugs can be synthesized in the laboratory, plants will continue to be an important source of such drugs. Why ? 4 x 5
5. Attempt any five questions.
(a) What are antenna pigments and reaction center pigments ?
(b) What is Z-DNA ? How does it differ from normal B-DNA ?
(c) Describe the phenomenon of microtubule assembly and disassembly during spindle organization.
(d) What are the different types of RNA that participate in protein synthesis, and mention the role of each type of RNA?
(e) Give an idea how the transcriptionally active chromatin differs, from inactive chromatin in context to nucleosome organization.
(f) Write in brief the characteristics' of transposons. 4 x 5
Group-B
Answer any two questions.
6. Attempt any five questions.
(a) Explain emasculation and its usefulness in breeding.
(b) What are the merits and demerits of another culture and protoplast culture techniques ?
(c) Elucidate with examples the application of genetic engineering in agriculture.
(d) What is in vitro mutagenesis ? Mention any one method to perform in vitro mutagenesis.
(e) What is FISH and GISH ? Give a flow chart of the steps to raise FISH in plants.
(f) If we want to introduce the human insulin gene into a bacterial host to produce a large amount of human insulin, should we use the genomic CDNA or the CDNA ? Explain your reasoning. 4 x 5
7. Attempt any five questions.
(a) Explain the meaning of the terms reductional division and equational division. What is "reduced" or "kept equal" ? To which nuclear divisions do the terms refer ?
(b) What are the different pathways in DNA damage repair ?
(c) What is a transgenic organism ? What are some of the practical uses of transgenic organisms ?
(d) What do you mean by critical photoperiod and photoperiodic induction ? Explain.
(e) Briefly elucidate the mechanism of uptake of ion against concentration gradient.
(f) What is the reactions cat lyzed by the enzyme reverse transcriptase ? How is the enzyme used in recombinant DNA technology ?
8. Attempt any five questions:
(a) Explain witn suitable examples and reactions, transamination and nitrification.
(b) Explain climax vegetation.
(c) Distinguish between the following (i) circadian rythm / biological clock (ii) phototropism / photoperiodism.
(d) What is mutualism ? Explain with suitable examples.
(e) What is a "Biome" ? Mention the Earth's principal Biomes with reference to the characteristic plants they represent.
(f) What is carbon foot print ? 4 x 5
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