Botany H , 2013....for 3rd Semester,TU

1. Answer in brief: ................1 mark each

(a) Name two de-nitrifying bacteria .

(b) What is meant by eucarpic thallus?

(c) What is episome?

(d) Distinguish between primary and secondary mycelium.

(e) What is non-systemic fungicide ?

2. Mention the living and non- living characters of virus . Describe the structure of TMV with suitable diagram . Discuss the basic features of lytic and lysoenic cycles . 4+(5+2)+4=15

 

3. Why are bacteria called prokaryotes ?

Describe generalised transduction . How does it differ from specialised transduction? Compare the conjugation between F+ x F-  and  Hfr x F-. 2+(5+2)+6

4. What are ascocarps ? Mention the different types of ascocarps .Briefly describe the structure and development of ascocarps of Penicillium and Ascobolus. Out of these two , which one should be considered as more advanced and why ?

1+1¹/2+(2+8)+1+1¹/2

5. Why are the species of Polyporus called as bracket fungi ? Name the process through which Polyporus performs sexual reproduction .With labelled sketches, describe the formation of basidiocarp of Polyporus . Comment on its spore dispersal mechanism .Name one edible and one harmful species of Polyporus . 1+1+ (2+6)+3+1+1

6. Write the name of pathogen of late blight of potato. Discuss the symptoms of this disease. Schematically represent the disease cycle with predisposing factors . Mention the effective control measures.2+5+3+2+3

7. What do you mean by quarantine regulation ? Why is it important in management of plant disease ? Classify the plant diseases based on causal organisms and occurrence . 2+4+5+4

8.What are Lichens? How many types of lichens are found in nature ? With labelled sketches, describe the internal structres of heteromerous type of lichen . Write about the different specialized structures associated with lichen thallus .

1+3+(2+4)+5

9. What is mycotoxin and mycotoxicosis ? Mention the names of different types of aflatoxins with source. Describe in brief the mode of action of aflatoxin .

2+2+8+3

                (from 2017 paper)

 1 .What is 'fairy ring'? Describe the structure of basidiocarp of Polyporus with suitable labelled diagram . 2+(6+2)

2. Name the causal organism of Brown spot of rice disease  and black stem rust of wheat .Name two disease resistant varieties of rice and wheat respectively.(1+1)+(2+2)