LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
B.Sc. DEGREE EXAMINATION – PLANT BIOLOGY & BIOTECHNOLOGY
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SECOND SEMESTER – APRIL 2006
PB 2502 – PTERIDO., GYMNO., & PALEOBOTANY
(Also equivalent to PB 2500)
Date & Time : 24-04-2006/1.00-4.00 P.M. Dept. No. Max. : 100 Marks
Part A
Answer all the questions (20 marks)
- Choose the correct answer (5 x 1 = 5 )
- Which one of the following fern is commonly called as club mosses
- a) Psilotum b) Lycopodium c) Equisetum d) Marsilea
- Name the scientist who proposed telome theory.
- a) Rimer b) Zimmermann c) Andrew d) Bohlin.
- Which of the following is used as a source of anticancer drug?
- a) Zamia b) Taxus c) Cycas d) Tsuga
- The ovule of Gnetum has _____ integuments.
- a) 1 b) 2 c) 3 d) 4
- Life originated in this planet about ______ billion years
- a) 3.5 b) 4.5 c) 1.5 d) 5.3
- State whether the following statements are True or False (5 x 1 = 5 )
- The gametophyte of Selaginella is exosporic.
- The leaves bearing sporangia are called elators.
- Ginkgo biloba is a living fossil.
- Welwitschia belongs to Coniferopsida.
- Compression fossils are commonly seen in coal mines.
III. Complete the following (5 x 1 = 5)
- Adiantum belongs to the class __________.
- In ferns, __________ phase is the dominant part of the life cycle.
- When centripetal and centrifugal xylem are present the condition is referred to as _______________
- Eccentric secondary growth is seen in _____________.
- Progymnosperms were discovered by ________________.
- Answer the following in about 50 words (5 x 1 = 5)
- What is amphiphloic siphonostele?
- Distinguish between heterospory and homospory.
- Distinguish between haplochelic and syndetochelic stomata.
- Describe the embryo of
- What is Petrifaction?
Part B
Answer any five of the following, each in about 350 words. Draw necessary diagrams. (5 x 8 = 40)
- With an example, explain the life cycle of a heterosporous Pteridophyte.
- Write notes on origin of Pteridophytes.
- Describe the life history of Psilotum.
- List out the characteristic features of Cordaitales.
- Enumerate the salient features of Cycadeoideales.
- Write notes on the anatomy of stem in Gnetum.
- Mention the conditions essential for fossilization. Add a note on changes that occur during fossilization.
- Describe the important features of Calamites. Compare it with
Part C
Answer the following questions in about 1500 words. Draw necessary diagrams
(2 x 20 = 40)
- a. Write notes on i) Heterospory precedes seed habit. Discuss.
ii). Briefly explain the types of stele.
(or)
- Give a comparative account of life cycle of Equisetum and Marsilea.
- Explain in detail about the structure of male and female cone in Pinus.
(or)
- Write in detail about the anatomy of stem and leaf in Cycas.