Chapter 3: Plant Kingdom – Case-Based / Source-Based Questions with Answers
CBSE Class 11 Biology Case-Based / Source-Based 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 – Case-Based & Source-Based Questions (NCERT)
Section A: Algae (Case 1–6)
Case 1
A student observes a simple, thalloid, aquatic plant body performing photosynthesis.
Q1. Identify the plant group.
Answer: Algae.
Q2. Mention one characteristic supporting this classification.
Answer: Presence of a thalloid body without true roots, stems, and leaves.
Case 2
An alga stores food in the form of starch and contains chlorophyll a and b.
Q3. Name the class of algae.
Answer: Chlorophyceae (green algae).
Case 3
A marine alga appears brown due to the presence of fucoxanthin.
Q4. To which class does it belong?
Answer: Phaeophyceae (brown algae).
Case 4
A red-coloured alga survives at greater depths in the sea.
Q5. Which pigment helps it survive there?
Answer: Phycoerythrin.
Case 5
An alga reproduces by fragmentation of its thallus.
Q6. Which mode of reproduction is this?
Answer: Vegetative reproduction.
Case 6
An alga is commercially used for agar production.
Q7. Name the algal group used.
Answer: Red algae (Rhodophyceae).
Section B: Bryophytes (Case 7–11)
Case 7
A small plant grows on land but requires water for fertilisation.
Q8. Identify the plant group.
Answer: Bryophytes.
Case 8
The dominant phase in a plant life cycle is gametophytic.
Q9. Which group shows this feature?
Answer: Bryophytes.
Case 9
A plant body has rhizoids instead of true roots.
Q10. What does this indicate?
Answer: It belongs to bryophytes.
Case 10
A thalloid plant like Marchantia is studied.
Q11. Name the subgroup of bryophytes.
Answer: Liverworts.
Case 11
A plant helps in soil formation and prevents erosion on rocks.
Q12. Which plant group performs this role?
Answer: Bryophytes.
Section C: Pteridophytes (Case 12–16)
Case 12
A plant has true roots, stems, leaves, and vascular tissues but no seeds.
Q13. Identify the plant group.
Answer: Pteridophytes.
Case 13
The dominant generation in a plant is sporophyte, and reproduction occurs by spores.
Q14. To which group does it belong?
Answer: Pteridophytes.
Case 14
A leaf bears sporangia on its lower surface.
Q15. What is such a leaf called?
Answer: Sporophyll.
Case 15
A pteridophyte produces two different types of spores.
Q16. Name this condition.
Answer: Heterospory.
Case 16
A plant contributes to coal formation in ancient times.
Q17. Which group is responsible?
Answer: Pteridophytes.
Section D: Gymnosperms (Case 17–20)
Case 17
A tree bears naked seeds not enclosed in fruits.
Q18. Identify the plant group.
Answer: Gymnosperms.
Case 18
Seeds are produced in cones and pollination occurs by wind.
Q19. Name the reproductive structure involved.
Answer: Cones.
Case 19
A plant shows no dependence on water for fertilisation.
Q20. Which group does it belong to?
Answer: Gymnosperms.
Case 20
A plant provides timber and resin commercially.
Q21. Name one such plant group.
Answer: Gymnosperms (e.g., Pinus).
Section E: Angiosperms & Life Cycle Patterns (Case 21–25)
Case 21
A flowering plant produces seeds enclosed within fruits.
Q22. Identify the plant group.
Answer: Angiosperms.
Case 22
Two cotyledons and reticulate venation are observed in a plant.
Q23. Classify the plant.
Answer: Dicotyledonous angiosperm.
Case 23
A plant shows double fertilisation.
Q24. Which plant group shows this feature?
Answer: Angiosperms.
Case 24
Both gametophyte and sporophyte generations are prominent in a plant.
Q25. Name the life cycle pattern.
Answer: Haplodiplontic life cycle.
Case 25
The sporophyte is the dominant and independent phase in a plant’s life cycle.
Q26. Name one plant group showing this life cycle.
Answer: Angiosperms (diplontic life cycle).
Exam Relevance
✔ Strictly NCERT-aligned
✔ Ideal for CBSE Class 11 case-based/source-based questions
✔ Covers all plant groups and life cycle patterns
✔ Strengthens application, reasoning, and comparison skills