UPSC Mains BOTANY-PAPER-I 2023

What are prions? How do they differ from viruses? Mention few diseases caused by prions in animals and human beings.

What is parasexuality in fungi? Explain the mechanism of parasexual cycle. What are the applications of parasexuality?

State the distinguishing features of Cyanophyceae. Discuss the phylogeny and affinities of Cyanophyceae with other groups.

Discuss the distribution of different modern species of Cycas found in India. Enumerate the fern characters observed in Cycas.

State the principles of International Code of Botanical Nomenclature. How are Operational Taxonomic Units (OTUs) used in numerical taxonomy?

What is lichen? With suitable diagrams, describe its types and structure. Write a note on the economic importance of lichens.

Describe the three modes of sexual reproduction in bacteria.

Characterise progymnosperms with examples. Mention their phylogenetic significance.

Define microbial biopesticides. What are their types? With suitable examples, evaluate the potential of microbial biopesticides in pest and disease control in crop plants.

Explain the general features of viroids. How do they differ from viruses? Name two diseases caused by virions.

Distinguish between the natural and phylogenetic systems of plant classification. Mention their merits and demerits.

Diagrammatically present the Geological Time Scale up to Epoch'. Write a note on the different types of fossils found in nature.

Describe the symptoms, causal organism, disease cycle and control measures of red rot of sugarcane.

What is stele? Give an illustrated account of various types of steles observed in pteridophytes.

Alphonse de Candolle classified plants of economic importance into various classes. List these classes and state two examples from each.

What are the anatomical differences of the bundle sheath and mesophyll cells between C3 and C4 plants?

Give an account of different types of trichomes found in modern angiosperms. Write a brief note on the systematic value of trichomes.

Discuss the classification of vegetable fibers (excluding wood fibers) according to their botanical origin and give examples.

How is the isolation of single cells done from intact plant organs and how is the viability of single cells assessed?

What are the different means of pollination in plants? Which natural devices ensure cross-pollination?

Using diagrams, explain the characteristic features of the family Magnoliaceae. Why is this family considered primitive?

Discuss the growth conditions of groundnut and soybean crops. Compare their oil compositions.

Describe the botanical features, ecology and propagation of rubber tree. How is rubber obtained and processed from rubber tree?

Classify and discuss maize varieties on the basis of endosperm and floral or glume characteristics.

What causes somaclonal variations? How can somaclones be identified and isolated?

What factors affect in vitro stages of micropropagation? Discuss the applications and limitations of micropropagation.

Give an account of male gametophyte development in Gnetum. State the angiosperm characters shared by Gnetum.

Discuss the factors affecting the yield and viability of protoplasts isolated from leaves. How are isolated protoplasts purified?