A few Questions for BSc Third Sem TU 212,BotH

1. Ans in brief.  1 mark each

a. What is clump formation?

b.What is brachymeiosis?

c. What is viroid?

d.What is flagellin?

e. Give the composition of Bordeaux mixture.

f.Name the biological source of orcein.

g. What is mycotoxicosis ?

h.Which type of bacteria are called pleomorphic type ?

 i.What is bacteriophae ?

2. Give an account of the cell wall structures and composition of gm+ & gm- bacteria.Add a note on their appendages .8+4

3. What do you mean by acid-fast bacteria? 2

4. What is meant by dikaryotization ?2

5. Add a note on spore dispersal in Agaricus spp.5

6. Why is Deuteromycetes called as imperfect fungi ? Mention different types of spores of Deuteromycetes . Write economic importance of this group.1+4+3

7. Mention the different ways through which the plant pahogen gets entry within the host tissue.2

8. Describe in brief the host-parasite relationship which leads to the disease establishment .7

9. What is hypersensitivity ?2

10.Write a brief note on biological control of plant diseases .4

11.Define incubation period.2

12. Why is Puccinia graminis tritici called heteroecious rust ? Name the different types of spores of it with ploidy level.2+5

13. Write the symptoms and control of black stem rust of wheat.3+3

14. Why are lichens exemplified as a case of symbiosis ? 2

15. Describe the different ways through which lichens reproduce asexually .6

16. Evaluate the role of lichens as pioneer of rock vegetation .3

17. Name the lichen , from which litmus is obtained  1

18. Note on effect of aflatoxin on human beings . 3