UPSC Mains BOTANY-PAPER-I 2025

28 Questions • 400 Marks • With Detailed Model Answers

1
10 Marks150 Wordsmedium

SECTION A

Answer the following questions in about 150 words each :

(a) How many types of gametophytes are found in Lycopodium ? Why is it difficult to collect such prothalli in nature ?

BotanyPlant Biology
2
10 Marks150 Wordsmedium

(b) How does heterocyst differ from vegetative cell ? Mention the factors controlling its formation and add a note on functions of heterocysts.

BotanyMicrobiology
3
10 Marks150 Wordseasy

(c) Explain how the numerical expression of data is utilized in plant systematics.

BotanySystematics
4
10 Marks150 Wordsmedium

(d) "Mycoplasma causes serious diseases in humans, animals and plants." Substantiate the statement with suitable examples.

BotanyZoologyMedicine
5
10 Marks150 Wordsmedium

(e) How does the infection of a pathogen affect the host plant physiology ?

BotanyPlant Pathology
6
20 Markshard

Q2. (a) Enumerate the types of fruiting bodies of Ascomycota and Basidiomycota. Write the various steps of ascus formation in Ascomycetous members with suitable illustrations.

BotanyMycology
7
15 Marksmedium

(b) What are the various modes of infection and dissemination of plant diseases caused by viruses ? Describe.

BotanyPlant PathologyVirology
8
15 Marksmedium

(c) Briefly describe the male and female strobili of Gnetum with suitable labelled diagrams. Why should you consider this plant a gymnosperm ?

BotanyGymnosperms
9
20 Markshard

Q3. (a) Discuss how progressive sterilization of sporogenous tissue occurs in bryophytes, with suitable diagrams and examples.

BotanyBryophytes
10
15 Marksmedium

(b) Describe the ranges of thallus organization in the members of Chlorophyceae.

BotanyAlgae
11
15 Marksmedium

(c) Explain holotype, isotype, paratype, lectotype and neotype. Mention the advantages of binomial system of plant nomenclature.

BotanySystematicsNomenclature
12
20 Markshard

Q4. (a) Describe the causal organisms, disease cycle and control measures of Early Blight of Potato and Blast of Rice.

BotanyPlant Pathology
13
15 Markshard

(b) What are eusporangiate and leptosporangiate sporangia ? Classify the sori based on the mode of development of sporangia in ferns, with suitable illustrations.

BotanyPteridophytes
14
15 Markshard

(c) Give an account of structural variation in the megasporophylls of different Cycas species with illustrations. Add a brief note on the primitive features in Cycas.

BotanyGymnosperms
15
10 Marks150 Wordsmedium

SECTION B

Answer the following questions in about 150 words each :

(a) Give an account of post-fertilization changes leading to formation of seeds in angiosperms.

BotanyAngiosperms
16
10 Marks150 Wordsmedium

(b) What are the various anomalies causing anomalous secondary growth in dicotyledonous plants ?

BotanyPlant Anatomy
17
10 Marks150 Wordseasy

(c) Name three important Indian Botanical Gardens and discuss briefly the role of botanical gardens in modern plant research.

BotanyConservationResearch
18
10 Marks150 Wordseasy

(d) Mention the botanical name and family of plants from which Aconite, Isabgol, Ashwagandha, Vasaka and Ipecac are obtained.

BotanyPharmacognosyEthnobotany
19
10 Marks150 Wordsmedium

(e) What is embryo rescue ? How does this method help in crop improvement ? State two disadvantages of it.

BotanyBiotechnologyAgriculture
20
20 Markshard

Q6. (a) What are the diagnostic characters of the families – Cucurbitaceae and Poaceae ? Write the botanical names and economic importance of any five members from each family.

BotanySystematicsEconomic Botany
21
15 Marksmedium

(b) Comment on Vavilov's contributions on the origin of cultivated plants. Write the botanical name and parts used of any three dye-yielding plants of India.

BotanyAgricultureEthnobotany
22
15 Marksmedium

(c) What is the importance of pollen storage ? Explain the methods adopted for storage of pollen grains. Add a note on test tube fertilization.

BotanyBiotechnologyReproduction
23
20 Marksmedium

Q7. (a) Write the botanical name, family, morphology of useful parts and uses of the following plants :

(i) Safflower

(ii) Fennel

(iii) Chicory

(iv) Tapioca

(v) Teak

BotanyEconomic Botany
24
15 Markshard

(b) Explain the various steps involved in plant protoplast culture. Mention the major limitations of this technique. What is the role of somatic hybridization in crop improvement ?

BotanyBiotechnologyAgriculture
25
15 Markshard

(c) Give an account of different types of axial parenchyma found in dicotyledonous woody plants stating their phylogenetic significance. Mention two primitive and two advanced features of ray parenchyma.

BotanyPlant Anatomy
26
20 Markshard

Q8. (a) What is micropropagation and how does it differ from traditional plant propagation methods ? Give an account of the applications of micropropagation in crop improvement and conservation of endangered plants. Add a brief note on the challenges of this technique.

BotanyBiotechnologyAgriculture
27
15 Marksmedium

(b) Distinguish between polyembryony and parthenocarpy. Classify parthenocarpy and add a note on its significance.

BotanyReproduction
28
15 Markshard

(c) Give an outline on the process of producing cybrids. How do cybrids differ from hybrids in terms of their genetic composition ? Comment on the potential applications of cybrid technology.

BotanyBiotechnologyGenetics