IGNOU BBYCT-131 December 2025 Previous Year Question Paper

Q1.(a) State whether the following statements are True or False : 4x1=4

(6) Robert Koch laid down the foundation of Germ Theory.

(ii) The algae Spirogyra are found in slow moving water.

(iii) The scouring powder derived from algae is called diatomite.

(iv) Rhynia was discovered in Ireland.

(b) Choose the correct option from those given in the parentheses : 4x1=4

(6) In (siphonostele/haplostele), there is no pith in the centre of the xylem core.

(ii) The accessory transfusion tissue functions as (secretory tissue/ conducting tissue) in the leaflets of Cycas.

(ii) Among the = softwoods (Taxus baccatal Thuja plicata) offers the heaviest wood.

(iv) The fossil resin secreted by Pinus succinifera is called (Canada balsam/Amber)

(c) Match the items given under Column ‘A’ with those given under Column ‘B’ : 4xo=2 Column A Column B

(1) Chitosan @) Stale bread

(2) Rhizopus

(ii) Symbiotic relationship

(3) Host-fungal

(iii) Exchange of association nutrients

(4) Harting

(iv) Poly-B -(1, 4) nets glucosamine

Q2.Differentiate between the following : 4x2°=10

(a) Helical symmetry and Complex symmetry of viruses

(b) Gram positive and Gram negative bacteria

(c) Hormogonia and Akinetes

(d) Gymnosperms and Angiosperms

Q3.Explain the different means of reproduction in algae with the help of well labelled diagrams.

Q4.(a) Write a short account of the discovery of viruses. 5

(b) Write about the economic importance of bacteria.

Q5.(a) Describe the ecology and distribution of algae. 5

(b) Describe the reproduction in Selaginella with diagrams.

Q6.(a) Describe the thallus organization in fungi with diagrams. 5

(b) Explain the ecological importance of Bryophytes.

Q7.Write short notes on any two of the following : 2x5=10

(a) Aesthetic value of conifers

(b) Fertilization in Pinus

(c) Formation of fossils in pteridophytes and their types

(d) Structure of Sporophyte in Funaria 2x5=

(10)