Chapter 3: Plant Kingdom – Short Answer Type Questions

CBSE Class 11 Biology Short Answer Questions – Chapter 3: Plant Kingdom (NCERT Based)

Course Details

Course: CBSE Class 11 Biology
Syllabus: NCERT
Unit: Unit I – Diversity in Living World
Chapter: Chapter 3 – Plant Kingdom
CBSE Board Examination: Central Board of Secondary Education – Class 11 (School & Annual Examinations)

CBSE Class 11 Biology Chapter 3 Plant Kingdom – 40 Short Answer Questions with Answers (NCERT)

Section A: Algae (Q1–Q10)

1. Describe the general characteristics of algae.
   Algae are simple, photosynthetic organisms with a thalloid body lacking true roots, stems, and leaves. They are mostly aquatic and reproduce vegetatively, asexually, and sexually.
2. Explain the basis of classification of algae.
   Algae are classified based on photosynthetic pigments, nature of stored food, and cell wall composition into green, brown, and red algae.
3. State two features of Chlorophyceae.
   Chlorophyceae possess chlorophyll a and b and store food as starch. Their cell wall is made of cellulose.
4. Mention the characteristics of brown algae.
   Brown algae are mostly marine, contain fucoxanthin pigment, and store food as laminarin and mannitol.
5. Why are red algae mostly marine?
   Red algae possess phycoerythrin, which absorbs blue light effectively, allowing them to survive at greater depths in marine environments.
6. State the economic importance of algae.
   Algae are used as food, fertilizers, and in the production of agar, algin, and carrageenan.
7. How do algae reproduce vegetatively?
   Vegetative reproduction in algae occurs mainly through fragmentation of the thallus.
8. What is the plant body organisation in algae?
   Algae show a thalloid body organisation without differentiation into roots, stems, and leaves.
9. Explain sexual reproduction in algae.
   Sexual reproduction in algae may be isogamous, anisogamous, or oogamous depending on the nature of gametes.
10. Name one edible alga and its use.
    Spirulina is an edible alga used as a protein-rich dietary supplement.

Section B: Bryophytes (Q11–Q18)

11. Why are bryophytes called amphibians of the plant kingdom?
    Bryophytes live on land but require water for sexual reproduction, hence they are called amphibians of the plant kingdom.
12. Describe the general features of bryophytes.
    Bryophytes are small, non-vascular plants with a dominant gametophyte and a dependent sporophyte.
13. Explain the structure of bryophyte plant body.
    The plant body is thalloid or leafy and bears rhizoids for anchorage instead of true roots.
14. What is the dominant phase in bryophytes and why?
    The gametophyte is dominant because it is independent and photosynthetic, while the sporophyte is dependent.
15. Differentiate between liverworts and mosses.
    Liverworts have a thalloid body, while mosses have a leafy structure with a distinct stem and leaves.
16. State the ecological importance of bryophytes.
    Bryophytes prevent soil erosion, help in soil formation, and maintain moisture in forests.
17. Explain alternation of generations in bryophytes.
    Bryophytes show haplodiplontic life cycle with alternating gametophytic and sporophytic phases.
18. Mention one economic importance of bryophytes.
    Sphagnum is used as fuel and in horticulture due to its water-holding capacity.

Section C: Pteridophytes (Q19–Q26)

19. Describe the general characteristics of pteridophytes.
    Pteridophytes are the first vascular land plants with true roots, stems, and leaves, reproducing by spores.
20. Why are pteridophytes considered first true land plants?
    They possess vascular tissues that enable efficient transport of water and nutrients on land.
21. Explain the dominant phase in pteridophytes.
    The sporophyte is dominant, independent, and photosynthetic, while the gametophyte is small and short-lived.
22. What is the role of spores in pteridophytes?
    Spores help in reproduction and dispersal of pteridophytes.
23. Describe the structure of sporophyll.
    Sporophylls are specialised leaves bearing sporangia that produce spores.
24. Differentiate between homosporous and heterosporous pteridophytes.
    Homosporous produce one type of spore, while heterosporous produce microspores and megaspores.
25. State one economic importance of pteridophytes.
    Many pteridophytes are used as ornamental plants.
26. Give an example of a pteridophyte.
    Equisetum is a common example of pteridophyte.

Section D: Gymnosperms (Q27–Q32)

27. Define gymnosperms.
    Gymnosperms are seed-bearing plants with naked seeds not enclosed within fruits.
28. Describe the reproductive structures of gymnosperms.
    They bear male and female cones that produce pollen and ovules respectively.
29. Explain pollination in gymnosperms.
    Pollination occurs mainly by wind due to exposed ovules and light pollen grains.
30. Why are gymnosperms mostly evergreen?
    They have needle-like leaves with thick cuticle, reducing water loss.
31. State the economic importance of gymnosperms.
    They provide timber, resins, and medicinal products.
32. Name two examples of gymnosperms.
    Pinus and Cycas are common gymnosperms.

Section E: Angiosperms & Life Cycle Patterns (Q33–Q40)

33. What are angiosperms?
    Angiosperms are flowering plants with seeds enclosed within fruits.
34. Explain double fertilisation in angiosperms.
    One male gamete fuses with egg to form zygote, while another fuses with polar nuclei to form endosperm.
35. Differentiate between monocots and dicots.
    Monocots have one cotyledon and parallel venation, while dicots have two cotyledons and reticulate venation.
36. Why are angiosperms considered most advanced plants?
    They possess flowers, fruits, efficient vascular tissues, and complex reproductive mechanisms.
37. Explain alternation of generations in plants.
    Plants alternate between haploid gametophyte and diploid sporophyte generations.
38. Describe haplontic life cycle.
    In haplontic life cycle, the gametophyte is dominant and sporophyte is short-lived.
39. What is diplontic life cycle?
    In diplontic life cycle, the sporophyte is dominant while gametophyte is highly reduced.
40. Which life cycle is found in bryophytes and pteridophytes?
    They show a haplodiplontic life cycle with both phases well represented.

Exam Relevance

✔ Strictly NCERT-aligned
✔ Ideal for 2–3 mark CBSE Class 11 questions
✔ Strong focus on differences and evolutionary trends
✔ Suitable for school tests and annual examinations