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PSEB CLASS XI BIOLOGY SAMPLE PAPER SET 1 

September Examination 2025
Subject: Biology  
Maximum Marks: 70
Time Allowed: 3 Hours

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General Instructions:

1. All questions are compulsory.

2. The question paper consists of four Sections A, B, C and D with a total of 19 questions.

3. Internal choice has been provided in some questions.

4. Use of diagrams is necessary wherever indicated.

5. The language used should be precise and to the point.

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Section A (1 × 20 = 20 Marks)

Q.1 Answer the following (20 parts):

(i–xii) Multiple Choice Questions

1. ICBN stands for:
   (a) Indian Code of Botanical Nomenclature
   (b) International Code of Botanical Nomenclature
   (c) Indian Congress of Botanical Names
   (d) International Congress for Biological Names

2. Correct hierarchical sequence is:
   (a) Phylum → Class → Order → Family
   (b) Genus → Species → Order → Family
   (c) Division → Order → Class → Genus
   (d) Phylum → Division → Family → Class

3. Ex-situ conservation includes:
   (a) Botanical gardens
   (b) Seed banks
   (c) Wildlife Safari parks
   (d) All of these

4. Sac fungi are:
   (a) Phycomycetes
   (b) Ascomycetes
   (c) Basidiomycetes
   (d) Deuteromycetes

5. First vascular plants were:
   (a) Bryophytes
   (b) Pteridophytes
   (c) Cycadales
   (d) Gnetales

6. Lichens are association of:
   (a) Algae and bacteria
   (b) Fungi and higher plants
   (c) Algae and fungi
   (d) Viruses and bacteria

7. Animals with four-chambered heart are:
   (a) Amphibians, Reptiles, Birds
   (b) Crocodiles, Birds, Mammals
   (c) Crocodiles, Lizards, Turtles
   (d) Lizards, Mammals, Birds

8. In monocot seed, the layer between endosperm and embryo is:
   (a) Testa
   (b) Aleurone layer
   (c) Tegmen
   (d) Scutellum

9. Polyadelphous condition is found in:
   (a) Corolla
   (b) Androecium
   (c) Gynoecium
   (d) Calyx

10. Cortex lies between:
    (a) Epidermis and stele
    (b) Pericycle and endodermis
    (c) Endodermis and pith
    (d) Endodermis and vascular bundle

11. Powerhouse of the cell is:
    (a) Golgi bodies
    (b) Mitochondria
    (c) Ribosomes
    (d) Endoplasmic reticulum

12. Amphibians show:
    (a) Dual habitat
    (b) Moist skin
    (c) Three-chambered heart
    (d) All of these

(xiii–xvi) Fill in the blanks:
13. Whittaker’s five kingdoms are Monera, Protista, Fungi, Plantae and ______.
14. In angiosperms ovary ripens into ______.
15. Animals with three primary germ layers are called ______.
16. Primary root develops from the ______.

(xvii–xx) True or False:
17. Root hairs are multicellular.
18. If both male and female parts are present in one flower, it is called unisexual flower.
19. Pseudocoel is found in flatworms.
20. Megaspore on germination produces female gametophyte.

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Section B (10 × 2 = 20 Marks)

Q.2 – Q.11 (2 marks each)

2. Write two advantages of binomial nomenclature.

3. What is mycorrhiza?

4. (a) Name pigments present in red algae.
   OR
   (b) What is numerical taxonomy?

5. (a) Write four salient features of Arthropoda.
   OR
   (b) Write four salient features of Annelida.

6. State four flight adaptations of birds.

7. What is perigynous ovary?

8. Define phyllotaxy.

9. (a) Name components of xylem and phloem.
   OR
   (b) Differentiate between cymose and racemose inflorescence.

10. What is periderm?

11. (a) Differentiate between poikilothermal and homeothermal animals.
    OR
    (b) How are viroids different from viruses?

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Section C (5 × 3 = 15 Marks)

12. (a) Draw and label a bacterial cell.
    OR
    (b) Draw and label Euglena.

13. What are the characteristic features of Euglenoids?

14. (a) Enlist six characters of Class Reptilia with examples.
    OR
    (b) Describe the characteristic features of chordates.

15. (a) Define: (i) Aestivation (ii) Placentation (iii) Superior ovary.
    OR
    (b) Draw labelled diagrams of V.S. of maize seed and V.S. of gram seed.

16. Describe structure and function of mitochondria.

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Section D (3 × 5 = 15 Marks)

17. (a) Draw a well-labelled diagram of monocot stem and explain three anatomical features.
    OR
    (b) Explain types of inflorescence with suitable diagrams.

18. (a) Differentiate:
    (i) Red algae and Brown algae
    (ii) Gymnosperms and Angiosperms
    OR
    (b) List and explain five adaptations in birds that help them to fly.

19. Comprehension (from Chapter 9: Biomolecules):

Biomolecules are chemical constituents of living cells. Carbohydrates provide immediate energy. Proteins have structural and enzymatic roles; enzymes are biological catalysts. Lipids are energy reserves and form membranes. Nucleic acids (DNA, RNA) store and transfer genetic information. Enzyme activity is influenced by temperature and pH.

Answer the following (1 mark each):
(i) Name two biomolecules.
(ii) What is the function of enzymes?
(iii) Give one function of lipids.
(iv) What happens to enzyme activity at very high temperature?
(v) Which biomolecule stores genetic information?

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