Chapter 1: Reproduction in Organisms – MCQs with Answers & Explanations
CBSE Class 12 Biology – MCQs with Answers and Explanations
Unit I: Reproduction | Chapter 1: Reproduction in Organisms (NCERT Based)
Course & Examination Details
- Course: CBSE Class 12 Biology
- Prescribed By: Central Board of Secondary Education
- Syllabus Reference: NCERT
- Unit: Unit I – Reproduction
- Chapter: Chapter 1 – Reproduction in Organisms
- Exam Focus: CBSE Class 12 Board Examinations (Objective / Competency-Based Questions)
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CBSE Class 12 Biology Chapter 1 MCQs with Answers & Explanations – Reproduction in Organisms (NCERT)
Section A: Lifespan, Ageing, and Senescence
Q1. The lifespan of an organism is best defined as:
A. Period of active reproduction
B. Time between germination and flowering
C. Duration from birth to natural death
D. Time between fertilisation and maturity
Correct Answer: C
Explanation: Lifespan refers to the total duration from birth to natural death and is a genetically determined, species-specific characteristic.
Q2. Which of the following is a correct statement about ageing?
A. It is reversible
B. It occurs only in animals
C. It is a gradual decline in physiological efficiency
D. It begins only during senescence
Correct Answer: C
Explanation: Ageing is a continuous and irreversible process involving gradual decline in body functions after maturity.
Q3. Senescence is best described as:
A. Beginning of reproduction
B. Final phase of ageing
C. Period of rapid growth
D. Juvenile phase
Correct Answer: B
Explanation: Senescence represents the last stage of ageing, marked by severe physiological deterioration leading to death.
Q4. Which organism is likely to have the longest lifespan?
A. Housefly
B. Dog
C. Elephant
D. Banyan tree
Correct Answer: D
Explanation: Some plants like the banyan tree can live for several hundred years, far longer than animals.
Q5. Lifespan variation among species is primarily due to:
A. Habitat only
B. Genetic makeup
C. Reproductive method
D. Body size alone
Correct Answer: B
Explanation: Lifespan is genetically determined, though environmental factors may influence it.
Section B: Types of Reproduction
Q6. Reproduction ensures:
A. Individual survival
B. Increase in body size
C. Continuity of species
D. Metabolic balance
Correct Answer: C
Explanation: Reproduction maintains species continuity by producing new individuals.
Q7. Which type of reproduction produces genetically identical offspring?
A. Sexual reproduction
B. Vegetative reproduction
C. Asexual reproduction
D. All of the above
Correct Answer: C
Explanation: Asexual reproduction involves no meiosis or fertilisation, producing clones.
Q8. Genetic variation is a characteristic feature of:
A. Binary fission
B. Budding
C. Fragmentation
D. Sexual reproduction
Correct Answer: D
Explanation: Sexual reproduction involves meiosis and fusion of gametes, leading to variation.
Q9. Which reproduction type is faster and energy efficient?
A. Sexual reproduction
B. Asexual reproduction
C. Internal fertilisation
D. External fertilisation
Correct Answer: B
Explanation: Asexual reproduction is rapid as it requires only one parent and no gamete formation.
Q10. Clones are produced through:
A. Fertilisation
B. Meiosis
C. Asexual reproduction
D. Sexual reproduction
Correct Answer: C
Explanation: Clones are genetically identical individuals formed by asexual reproduction.
Section C: Asexual Reproduction
Q11. Binary fission commonly occurs in:
A. Hydra
B. Amoeba
C. Spirogyra
D. Yeast
Correct Answer: B
Explanation: Amoeba reproduces by binary fission, dividing into two identical daughter cells.
Q12. Multiple fission is characteristic of:
A. Hydra
B. Amoeba
C. Plasmodium
D. Planaria
Correct Answer: C
Explanation: Plasmodium undergoes multiple fission, producing many offspring at once.
Q13. Budding is seen in:
A. Amoeba
B. Hydra
C. Plasmodium
D. Spirogyra
Correct Answer: B
Explanation: Hydra reproduces by budding, where a small outgrowth forms a new individual.
Q14. Fragmentation is commonly seen in:
A. Bacteria
B. Algae
C. Protozoa
D. Fungi
Correct Answer: B
Explanation: Filamentous algae like Spirogyra reproduce by fragmentation.
Q15. Regeneration primarily helps in:
A. Sexual reproduction
B. Fertilisation
C. Repair and replacement
D. Gamete formation
Correct Answer: C
Explanation: Regeneration restores lost body parts and may lead to reproduction in some organisms.
Section D: Vegetative Propagation
Q16. Vegetative propagation is an example of:
A. Sexual reproduction
B. Asexual reproduction
C. Fertilisation
D. Pollination
Correct Answer: B
Explanation: Vegetative propagation uses plant parts and does not involve gametes.
Q17. Potato reproduces vegetatively through:
A. Root
B. Leaf
C. Stem tuber
D. Flower
Correct Answer: C
Explanation: Potato tubers are modified stems used in vegetative propagation.
Q18. Which is an artificial method of vegetative propagation?
A. Runner
B. Rhizome
C. Cutting
D. Tuber
Correct Answer: C
Explanation: Cutting is an artificial vegetative propagation method used in agriculture.
Q19. One major disadvantage of vegetative propagation is:
A. Slow reproduction
B. Lack of variation
C. Need for pollinators
D. High energy cost
Correct Answer: B
Explanation: Vegetatively propagated plants lack genetic variation and are vulnerable to diseases.
Q20. Plants produced vegetatively are genetically:
A. Different
B. Similar but not identical
C. Identical
D. Unstable
Correct Answer: C
Explanation: They are clones formed through mitotic divisions.
Section E: Sexual Reproduction
Q21. Sexual reproduction involves:
A. One parent
B. No gametes
C. Fusion of gametes
D. Only mitosis
Correct Answer: C
Explanation: Fusion of male and female gametes is essential in sexual reproduction.
Q22. Gametes are formed by:
A. Mitosis
B. Binary fission
C. Meiosis
D. Budding
Correct Answer: C
Explanation: Meiosis produces haploid gametes required for sexual reproduction.
Q23. Isogametes are:
A. Morphologically different
B. Morphologically similar
C. Non-functional
D. Diploid
Correct Answer: B
Explanation: Isogametes are similar in size and form.
Q24. Sexual reproduction is slower because:
A. It lacks meiosis
B. It requires gamete formation and fertilisation
C. It produces fewer offspring
D. It occurs only seasonally
Correct Answer: B
Explanation: Multiple steps make sexual reproduction time-consuming.
Q25. External fertilisation is common in:
A. Mammals
B. Birds
C. Aquatic animals
D. Reptiles
Correct Answer: C
Explanation: Water facilitates fusion of gametes in aquatic organisms.
Section F: Events in Sexual Reproduction
Q26. Gametogenesis refers to:
A. Fusion of gametes
B. Formation of gametes
C. Embryo development
D. Zygote division
Correct Answer: B
Explanation: Gametogenesis is the process of gamete formation by meiosis.
Q27. Fertilisation results in formation of:
A. Gamete
B. Embryo
C. Zygote
D. Ovum
Correct Answer: C
Explanation: Fusion of gametes produces a diploid zygote.
Q28. Internal fertilisation offers:
A. Less protection
B. No variation
C. Better survival
D. Lower energy cost
Correct Answer: C
Explanation: Internal fertilisation protects gametes and developing embryos.
Q29. Restoration of diploid chromosome number occurs during:
A. Meiosis
B. Mitosis
C. Fertilisation
D. Gametogenesis
Correct Answer: C
Explanation: Fertilisation restores diploid condition.
Q30. Gamete transfer occurs during:
A. Post-fertilisation
B. Pre-fertilisation
C. Embryogenesis
D. Senescence
Correct Answer: B
Explanation: Gamete transfer is a pre-fertilisation event.
Section G: Post-Fertilisation Events
Q31. Zygote develops into an embryo by:
A. Meiosis
B. Binary fission
C. Mitosis
D. Budding
Correct Answer: C
Explanation: Embryonic development occurs through mitotic divisions.
Q32. Embryogenesis involves:
A. Gamete formation
B. Cell differentiation
C. Fertilisation
D. Pollination
Correct Answer: B
Explanation: Embryogenesis includes division and differentiation of cells.
Q33. Oviparous animals:
A. Give birth to young ones
B. Show internal development
C. Lay eggs
D. Do not reproduce
Correct Answer: C
Explanation: Oviparous animals lay eggs outside the body.
Q34. Viviparous organisms show:
A. Egg laying
B. External fertilisation
C. Internal development
D. No fertilisation
Correct Answer: C
Explanation: Viviparous organisms develop embryos inside the mother.
Q35. Post-fertilisation events ensure:
A. Gamete formation
B. Population decline
C. Growth and development
D. Senescence
Correct Answer: C
Explanation: These events lead to formation of a functional organism.
Section H: Reproductive Health (Basic Concepts)
Q36. Reproductive health refers to:
A. Absence of disease only
B. Proper functioning of reproductive system
C. Population control
D. Sexual maturity
Correct Answer: B
Explanation: Reproductive health ensures healthy reproduction and viable offspring.
Q37. Which factor strongly affects reproductive health?
A. Colour
B. Nutrition
C. Body shape
D. Habitat size
Correct Answer: B
Explanation: Adequate nutrition supports hormone balance and fertility.
Q38. Environmental pollution can:
A. Improve fertility
B. Increase lifespan
C. Impair reproduction
D. Stop ageing
Correct Answer: C
Explanation: Pollution affects gamete formation and embryonic development.
Q39. Reproductive health is important because it:
A. Increases lifespan
B. Maintains species survival
C. Reduces population
D. Stops ageing
Correct Answer: B
Explanation: Healthy reproduction ensures survival and continuity of species.
Q40. Reproductive health applies to:
A. Humans only
B. Animals only
C. Plants only
D. All reproducing organisms
Correct Answer: D
Explanation: All organisms capable of reproduction require reproductive health.
Section I: Conceptual & Higher-Order MCQs
Q41. Lack of variation is a disadvantage of:
A. Sexual reproduction
B. Meiosis
C. Asexual reproduction
D. Fertilisation
Correct Answer: C
Explanation: Asexual reproduction produces genetically identical offspring.
Q42. Which reproduction type supports evolution?
A. Asexual
B. Vegetative
C. Sexual
D. Binary fission
Correct Answer: C
Explanation: Genetic variation from sexual reproduction drives evolution.
Q43. Reproduction without fertilisation occurs in:
A. Sexual reproduction
B. Asexual reproduction
C. Viviparity
D. Oviparity
Correct Answer: B
Explanation: Asexual reproduction does not involve fertilisation.
Q44. Sudden environmental change affects clones because they:
A. Are genetically diverse
B. Reproduce slowly
C. Lack adaptability
D. Have longer lifespan
Correct Answer: C
Explanation: Clones lack variation, reducing adaptability.
Q45. Which process ensures genetic continuity?
A. Ageing
B. Reproduction
C. Senescence
D. Regeneration
Correct Answer: B
Explanation: Reproduction transfers genetic material across generations.
Q46. Formation of haploid cells occurs during:
A. Fertilisation
B. Mitosis
C. Meiosis
D. Regeneration
Correct Answer: C
Explanation: Meiosis halves the chromosome number.
Q47. Which is NOT a pre-fertilisation event?
A. Gametogenesis
B. Gamete transfer
C. Fertilisation
D. Pollination
Correct Answer: C
Explanation: Fertilisation occurs after pre-fertilisation events.
Q48. Asexual reproduction is common in unicellular organisms because it is:
A. Complex
B. Slow
C. Efficient
D. Risky
Correct Answer: C
Explanation: It is simple and energy-efficient for unicellular life.
Q49. Decline in reproductive capacity is associated with:
A. Growth
B. Maturity
C. Senescence
D. Juvenile phase
Correct Answer: C
Explanation: Senescence reduces reproductive efficiency.
Q50. Ultimate purpose of reproduction is to:
A. Increase body size
B. Prevent ageing
C. Ensure survival of species
D. Stop death
Correct Answer: C
Explanation: Reproduction maintains species continuity despite individual death.
CBSE Board Exam Note
These 50 NCERT-based MCQs with detailed explanations are aligned with the CBSE Class 12 Biology board exam pattern, ideal for objective, competency-based, and revision practice.