How do Organisms Reproduce? – Short Answer Type Questions
Class 10
CBSE Board Examinations
Strictly per NCERT syllabus • Topic-wise • Clear answers for revision
Strictly per NCERT syllabus • Topic-wise • Clear answers for revision
Instructions: These short-answer questions (2–4 lines) are organised topic-wise for thorough revision and board exam practice. Answers are concise and exam-focused.
1. Basics of Reproduction (Q1–Q6)
Q1. Define reproduction.
Reproduction is the biological process by which organisms produce new individuals of the same species to ensure continuity.
Q2. Give two main types of reproduction.
Asexual reproduction (single parent, no gametes) and sexual reproduction (fusion of male and female gametes).
Q3. State one advantage of asexual reproduction.
Rapid multiplication without the need for a mate; useful in stable environments.
Q4. State one advantage of sexual reproduction.
Generates genetic variation among offspring, aiding adaptation and evolution.
Q5. What is a gamete?
A gamete is a haploid reproductive cell (sperm or egg) that fuses during fertilization to form a zygote.
Q6. Define zygote.
A zygote is the diploid cell formed when male and female gametes fuse during fertilization.
2. Asexual Reproduction (Q7–Q14)
Q7. What is binary fission? Give an example.
Binary fission is division of a unicellular organism into two equal parts; e.g., Amoeba and bacteria divide by binary fission.
Q8. What is budding? Example.
Budding is formation of a new individual as a bud on the parent which detaches later; e.g., Hydra and yeast.
Q9. Explain spore formation with an example.
Spores are reproductive cells produced by fungi and some plants; e.g., Rhizopus produces spores that germinate into new individuals.
Q10. What is fragmentation? Example.
Fragmentation is breaking of an organism into pieces that regenerate into complete organisms; e.g., Planaria and some algae.
Q11. How does parthenogenesis differ from other asexual methods?
Parthenogenesis is development of an egg into an organism without fertilization; observed in some insects and reptiles.
Q12. Why does asexual reproduction lack variation?
Because offspring arise from a single parent without gamete fusion, resulting in genetically identical (clonal) progeny.
Q13. Give one agricultural use of vegetative propagation.
Vegetative propagation helps produce uniform crops with desirable traits, e.g., potato tubers and sugarcane setts.
Q14. What is vegetative propagation?
A type of asexual reproduction in plants where new plants arise from vegetative parts like stems, roots, or leaves.
3. Vegetative Propagation (Q15–Q20)
Q15. Define grafting.
Grafting is joining a stem or bud of one plant (scion) onto the stem of another (rootstock) to grow as one plant.
Q16. What are tubers? Example.
Tubers are swollen underground stems storing food; e.g., potato tubers produce new plants from buds (eyes).
Q17. What are runners? Example.
Runners are horizontal stems that grow on soil and form new plants at nodes; e.g., strawberry plants.
Q18. What is cutting in horticulture?
Cutting is an artificial method where a stem or leaf piece is rooted to produce a new plant.
Q19. Why is vegetative propagation preferred for some crops?
It maintains genetic identity and yields plants identical to the parent with known traits and faster establishment.
Q20. Give one disadvantage of vegetative propagation.
Propagation of clones can spread diseases easily and reduces genetic diversity.
4. Sexual Reproduction — General (Q21–Q26)
Q21. Briefly define meiosis.
Meiosis is a specialized cell division that halves the chromosome number to form haploid gametes and introduces variation via recombination.
Q22. What is fertilization?
Fertilization is the fusion of male and female gametes to form a diploid zygote.
Q23. What is internal fertilization? Example.
Internal fertilization occurs within the female body; common in mammals, birds and reptiles (e.g., humans).
Q24. What is external fertilization? Example.
External fertilization occurs outside the body in water; e.g., fish and amphibians release gametes into water for fertilization.
Q25. Why is genetic variation important?
Variation provides raw material for natural selection and adaptation to changing environments.
Q26. Name two sources of genetic variation during sexual reproduction.
Crossing over during meiosis and independent assortment of chromosomes.
5. Reproduction in Flowering Plants (Q27–Q34)
Q27. What is pollination?
Pollination is the transfer of pollen grains from anther to stigma of a flower.
Q28. Distinguish self-pollination and cross-pollination (short).
Self-pollination: pollen to stigma of same flower/plant; cross-pollination: pollen transferred between different plants of same species.
Q29. Name two agents of pollination.
Wind and insects (bees, butterflies); birds and water also act as agents.
Q30. What is a pollen tube?
A pollen tube is a tube produced by a germinated pollen grain that delivers male gametes to the ovule.
Q31. Explain double fertilization briefly.
In double fertilization one male gamete fuses with egg to form zygote, another fuses with polar nuclei to form endosperm (triploid) for nutrition.
Q32. What does the ovule develop into?
An ovule develops into a seed after fertilization.
Q33. What does the ovary develop into?
The ovary develops into a fruit that encloses seeds.
Q34. Why is nectar important for some flowers?
Nectar attracts pollinators like bees and birds, aiding cross-pollination.
6. Human Male Reproductive System (Q35–Q38)
Q35. Where are sperms produced?
Sperms are produced in seminiferous tubules of the testes by spermatogenesis.
Q36. What is the role of testosterone?
Testosterone controls development of male secondary sexual characters and maintains spermatogenesis.
Q37. Name two accessory glands in the male reproductive system.
Seminal vesicles and prostate gland produce fluids that form semen and nourish sperm.
Q38. What is the function of epididymis?
Epididymis stores and matures sperm produced in the testes.
7. Human Female Reproductive System (Q39–Q44)
Q39. Where are ova produced?
Ova (eggs) are produced in the ovaries by oogenesis.
Q40. What is ovulation?
Ovulation is release of a mature ovum from the ovary into the fallopian tube.
Q41. Where does fertilization usually occur in humans?
Fertilization usually occurs in the fallopian tube (oviduct).
Q42. What is the function of the uterus?
The uterus provides a site for implantation and development of the embryo and fetus.
Q43. What is the placenta?
The placenta is a temporary organ connecting fetus to mother, allowing nutrient, gas exchange and waste removal.
Q44. What happens during menstruation?
If fertilization does not occur, the uterine lining sheds and exits the body as menstrual blood.
8. Gametogenesis & Menstrual Cycle (Q45–Q48)
Q45. Briefly define spermatogenesis.
Spermatogenesis is the formation of haploid sperm from diploid germ cells via meiosis in testes.
Q46. Briefly define oogenesis.
Oogenesis is the process by which ova are formed in ovaries, producing typically one mature egg per cycle.
Q47. Name two hormones that regulate the menstrual cycle.
Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) from the pituitary regulate the cycle alongside estrogen and progesterone.
Q48. Approximate duration of a normal menstrual cycle.
About 28 days (range 21–35 days among individuals).
9. Reproductive Health, Contraception & Applications (Q49–Q50)
Q49. Give two common methods of contraception.
Barrier methods (condom) and hormonal methods (birth control pills); IUDs and sterilization are other options.
Q50. Why is reproductive health education important?
It prevents STIs, unwanted pregnancies, promotes safe practices and informs about healthy reproductive choices.