Chapter 1: The Living World – Case-Based / Source-Based Questions with Answers
CBSE Class 11 Biology Case-Based / Source-Based Questions – Chapter 1: The Living World (NCERT Based)
Course Details
Course: CBSE Class 11 Biology
Syllabus: NCERT
Unit: Unit I – Diversity in Living World
Chapter: Chapter 1 – The Living World
CBSE Board Examination: Central Board of Secondary Education – Class 11 (School & Annual Examinations)
CBSE Class 11 Biology Chapter 1 The Living World – 20 Case-Based & Source-Based Questions with Answers (NCERT)
Section A: Characteristics of Living Organisms (Case 1–5)
Case 1
A scientist observes that a green plant bends towards light and its roots grow downward into the soil.
Q1. Which characteristic of living organisms is shown here?
Answer: The plant shows responsiveness or consciousness by reacting to light and gravity, which is a key characteristic of living organisms.
Q2. Name the specific responses shown by shoot and root.
Answer: The shoot shows phototropism, while the root shows geotropism.
Case 2
A crystal kept in a saturated solution increases in size over time.
Q3. Can this growth be compared with growth in living organisms? Give reason.
Answer: No, crystal growth is due to external deposition, whereas living organisms grow internally through cell division.
Q4. Why is growth not a defining characteristic of life?
Answer: Because non-living objects like crystals also show growth, and some living organisms may not show visible growth.
Case 3
A mule does not reproduce but performs all other life activities normally.
Q5. Does this mean reproduction is not essential for life? Explain.
Answer: Yes, reproduction is not a defining feature since some living organisms do not reproduce but are still alive.
Case 4
A laboratory enzyme catalyzes a biochemical reaction outside a living cell.
Q6. Does this reaction qualify as metabolism? Why or why not?
Answer: No, metabolism refers to reactions occurring within living cells, not isolated laboratory reactions.
Q7. Which characteristic of life does this highlight?
Answer: It highlights metabolism as a defining feature of living organisms.
Case 5
Viruses remain inactive outside a host cell but multiply rapidly inside it.
Q8. Why are viruses considered borderline between living and non-living?
Answer: They show life-like properties only inside a host cell and remain inert outside.
Section B: Diversity and Classification (Case 6–10)
Case 6
A student finds it difficult to study thousands of different organisms individually.
Q9. Which biological concept helps solve this problem?
Answer: Classification helps organize organisms into groups for easier and systematic study.
Q10. State one advantage of classification.
Answer: It helps in understanding relationships among organisms.
Case 7
Two organisms share similar body structure and mode of reproduction.
Q11. On what basis would they be grouped together?
Answer: They would be grouped based on morphological and reproductive similarities.
Case 8
A botanist arranges plants based on flower color for convenience.
Q12. Which type of classification is this?
Answer: This is artificial classification.
Q13. Why is this system not preferred scientifically?
Answer: It considers only a few characters and does not reflect natural relationships.
Case 9
Modern scientists use DNA similarities to classify organisms.
Q14. Which aspect of classification does this represent?
Answer: It represents modern systematics based on evolutionary relationships.
Case 10
Organisms grouped together share a common ancestor.
Q15. What term describes this evolutionary relationship?
Answer: This relationship is called phylogeny.
Section C: Nomenclature and Taxonomy (Case 11–15)
Case 11
The plant mango is known by different names in different regions.
Q16. Which system avoids such confusion?
Answer: Binomial nomenclature avoids confusion by providing a universal scientific name.
Case 12
A student writes Mangifera Indica instead of Mangifera indica.
Q17. Identify the error.
Answer: The species name should start with a small letter, not a capital letter.
Case 13
Scientific names are written in italics in textbooks.
Q18. Why is this formatting used?
Answer: Italics indicate standardized Latin scientific names.
Case 14
An organism is placed under genus Panthera.
Q19. What does this placement indicate?
Answer: It indicates the organism belongs to a group of closely related species.
Case 15
A biologist studies identification, naming, and classification of organisms.
Q20. Name this branch of biology.
Answer: This branch of biology is called taxonomy.
Section D: Taxonomic Categories and Aids (Case 16–20)
Case 16
A dried plant specimen is mounted on a labeled sheet for reference.
Q21. What is this collection called?
Answer: It is called a herbarium.
Case 17
Living plants are grown and arranged scientifically for study.
Q22. Name the taxonomical aid described.
Answer: Botanical garden.
Case 18
Animals are kept in protected environments for education and conservation.
Q23. Which taxonomical aid is this?
Answer: Zoological park.
Case 19
A student identifies a plant using paired contrasting characters.
Q24. Which tool is being used?
Answer: A taxonomic key is being used.
Case 20
An organism is classified as species → genus → family → order.
Q25. What does this sequence represent?
Answer: It represents the taxonomic hierarchy.
Exam Relevance
✔ Fully NCERT-aligned
✔ Ideal for CBSE Class 11 case-based questions
✔ Strengthens analytical and application-based skills
✔ Useful for internal assessments and annual exams