Class 9 Science Exploration Chapter 11 Solutions (NCERT 2026–27) – Reproduction: How Life Continues

These Class 9 Science Exploration Chapter 11 solutions cover Reproduction: How Life Continues from the new NCF-2023 textbook (2026–27).

Class: 9 Subject: Science Book: Exploration Chapter: 11 Exercise: Revise, Reflect, Refine (13 Qs) Session: 2026–27
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Class 9 Science Exploration Chapter 11 Solutions – Overview

Chapter 11 of Exploration, Reproduction: How Life Continues, explains how organisms produce new individuals so that life continues. It covers asexual reproduction (one parent, identical offspring) and sexual reproduction (two parents, variation), vegetative propagation and tissue culture, reproduction in flowering plants (pollination and fertilisation), and reproduction in humans including the menstrual cycle. These Class 9 Science Exploration Chapter 11 solutions answer every textbook question step by step.

Key Concepts & Definitions

Reproduction: the process by which living organisms produce new individuals of their own kind, so the species continues.

Asexual reproduction: a single parent produces genetically identical offspring (e.g., budding in yeast/hydra, vegetative propagation).

Sexual reproduction: two parents and the fusion of male and female gametes, producing offspring with genetic variation.

Pollination: transfer of pollen from anther to stigma — self- (same plant) or cross- (different plant). Fertilisation: fusion of the male gamete with the egg to form a zygote.

Vegetative propagation / tissue culture: asexual methods that quickly produce many genetically identical plants.

“Think It Over” — Answers

How can our knowledge of reproduction help increase crop production?

ANSWERBy using methods such as vegetative propagation, grafting and tissue culture, and by improving pollination, farmers can quickly grow many plants with desirable traits (good yield, taste or disease resistance), which raises crop production.

Why do offspring resemble their parents?

ANSWERBecause they inherit genetic material (DNA) from their parents during reproduction, and this DNA carries the instructions for their characteristics.

Class 9 Science Exploration Chapter 11 Solutions — Revise, Reflect, Refine

1. A flower’s anthers are removed before it matures. Later, pollen from another plant of the same species is dusted onto its stigma and seeds are produced. Which process has been ensured here? (i) Self-pollination (ii) Cross-pollination (iii) Fertilisation (iv) Tissue culture

ANSWERCorrect option: (ii) Cross-pollination. Removing the anthers prevents the flower’s own pollen from being used; dusting pollen from a different plant of the same species ensures pollen comes from another plant — that is cross-pollination.

2. Arrange the stages of sexual reproduction in plants in the correct order: (i) Pollen germination on stigma (ii) Fertilisation (iii) Pollination (iv) Formation of zygote

ANSWERCorrect order: Pollination → Pollen germination on stigma → Fertilisation → Formation of zygote (that is, iii, i, ii, iv).

3. Assertion (A): The zygote formed after fertilisation immediately attaches to the uterus wall. Reason (R): The uterus wall is always prepared to receive the zygote. (i) Both A and R are true, and R is the correct explanation of A. (ii) Both A and R are true, but R is not the correct explanation of A. (iii) A is true, but R is false. (iv) A is false, but R is true.

ANSWER Both the Assertion and the Reason are false. A is false: after fertilisation the zygote first divides to form an embryo (blastocyst), which then implants in the uterus wall after several days — not immediately. R is false: the uterus wall is not always prepared; its lining thickens only during a particular phase of the menstrual cycle to receive the embryo.

4. Why does asexual reproduction produce offspring that are genetically identical to the parent?

ANSWER Asexual reproduction involves only one parent and there is no fusion of gametes, so there is no mixing of genetic material. The offspring are formed by ordinary cell division (mitosis), so each receives an exact copy of the parent’s DNA — they are clones, genetically identical to the parent.

5. Explain why the menstrual cycle stops during pregnancy.

ANSWER After fertilisation and implantation, the thick uterus lining is needed to nourish and protect the developing embryo. Hormones (mainly progesterone) keep this lining intact and stop a new egg from being released, so the lining is not shed — therefore menstruation (and the cycle) stops during pregnancy.

6. Why are flowers that bloom at night white or light in colour compared to flowers that bloom during the day?

ANSWER Night-blooming flowers are pollinated mainly by night-active pollinators such as moths and bats. White or pale flowers reflect the dim light and stand out in the dark, making them easy for these pollinators to find. Day flowers can be brightly coloured because day pollinators (bees, butterflies) see colours well.

7. Why do vegetatively propagated plants tend to be more vulnerable to diseases than sexually reproduced plants?

ANSWER Vegetatively propagated plants are clones — genetically identical to the parent and to each other, with no genetic variation. So if a disease can affect one plant, it can affect all of them. Sexually reproduced plants have genetic variation, so some individuals may be resistant and survive.

8. If all flowers in a type of plant were only capable of self-pollination, how would it affect genetic diversity over several generations? Explain.

ANSWER Genetic diversity would decrease over generations, because no new genetic material is introduced from other plants. The offspring become more and more genetically uniform, which makes the population less able to adapt to changing conditions and more vulnerable to diseases and environmental stress.

9. A farmer wants to produce a large number of genetically identical plants quickly. Suggest suitable reproduction methods and explain why they are effective.

ANSWER The farmer should use asexual / vegetative methods such as cuttings, grafting, layering or tissue culture (micropropagation). These are effective because they produce clones — offspring genetically identical to the parent — so the desirable traits are preserved, and they are fast; tissue culture can produce hundreds of plants from a small piece of tissue in a short time.

10. Suresh prepares slides with pollen grains in different sugar concentrations (0%, 2.5%, 5%, 7.5%, 10%) to study pollen germination. (i) What hypotheses can be tested using this set-up? (ii) What parameters should be kept the same?

ANSWER (i) Possible hypotheses: “the sugar concentration affects the percentage of pollen germination”; “there is an optimum sugar concentration at which germination is maximum”; “higher sugar concentration increases (or decreases) germination.” (ii) Parameters to keep the same (controlled variables): the same type and amount of pollen, the same temperature, light, time of observation, volume of solution and pH — only the sugar concentration should change.

11. From the pictures, identify the type(s) of pollination likely in these flowers — Tomato (stamens cover the stigma), Wheat (flowers open after pollination), Papaya (male and female flowers often on different trees).

ANSWER Tomato: the stamens cover the stigma, so the flower’s own pollen reaches its stigma — self-pollination. Wheat: the flowers are pollinated before (or as) they open, so pollen from the same flower is used — self-pollination. Papaya: male and female flowers are on different trees, so pollen must travel from a male tree to a female tree — cross-pollination.

12. Apple orchards were studied at Place A (natural pollinators only) and Place B (beekeeping added). Fig. 11.24 shows the fruit setting and fruit drop at the two places. (i) What hypotheses might the researcher-farmers have thought of? (ii) What are the different parameters in the experiment? (iii) Compare and analyse the data of Places A and B for high apple yield. (iv) What do you infer from the data?

ANSWER (i) Hypothesis: “Adding managed bee colonies improves pollination, so it increases fruit setting and reduces fruit drop” (better pollination gives higher yield). (ii) Independent variable: the pollination method (natural pollinators at A vs added bee colonies at B). Dependent variables (measured): fruit setting (%) and fruit drop (%). Controlled: apple variety, climate/season and orchard management. (iii) From Fig. 11.24: fruit setting is higher at Place B (about 40%) than at Place A (about 26%), and fruit drop is much lower at Place B (about 8%) than at Place A (about 35%). (iv) Inference: adding bee colonies improves pollination, giving more fruit set and less fruit drop — so beekeeping increases apple yield and is an effective way to offset the decline in natural pollinators.

13. A student claims, “In humans, ovulation always happens on day 14 of the menstrual cycle.” Critically examine this claim and give at least two reasons.

ANSWER The claim is not correct as a general rule. Reason 1: Day-14 ovulation assumes a regular 28-day cycle; cycle length varies from person to person (and even month to month), so the day of ovulation varies. Reason 2: Ovulation can be shifted by factors such as stress, illness, hormonal changes, diet and age — so it does not always fall on day 14.

Common Mistakes to Avoid

Watch out for these

  • Thinking asexual reproduction creates variation — it produces genetically identical clones.
  • Confusing pollination (transfer of pollen) with fertilisation (fusion of gametes).
  • Mixing up self-pollination (same plant) and cross-pollination (different plant).
  • Believing the zygote implants in the uterus immediately — it implants after several days as an embryo.
  • Assuming ovulation is always on day 14 — it depends on the cycle length and other factors.
  • Thinking clonal (vegetatively propagated) crops are safer — their lack of variation makes them more vulnerable to disease.

Extra Practice Questions

Very Short Answer Type Questions

Q1. Name the male and female reproductive parts of a flower.

ANSWERThe stamen (male) and the carpel/pistil (female).

Q2. Give one example of an organism that reproduces by budding.

ANSWERYeast (or Hydra).

Q3. What is the product of fertilisation called?

ANSWERA zygote.

Short Answer Type Questions

Q1. State two advantages of sexual reproduction over asexual reproduction.

ANSWERIt produces variation among offspring, which helps a species adapt and evolve; and this variation gives some individuals a better chance of surviving diseases and changing conditions.

Q2. What is vegetative propagation? Give one example.

ANSWERIt is asexual reproduction in plants from a vegetative part (root, stem or leaf) without seeds, e.g., a new potato plant growing from the “eyes” of a potato tuber, or a rose plant grown from a stem cutting.

Long Answer Type Question

Q1. Describe the process of sexual reproduction in a flowering plant from pollination to seed formation.

ANSWER Pollination: pollen is transferred from the anther to the stigma (by wind, water or animals). The pollen grain germinates on the stigma and grows a pollen tube down the style to the ovule, carrying the male gametes. Fertilisation: a male gamete fuses with the egg in the ovule to form a zygote. The zygote develops into an embryo, the ovule becomes the seed, and the ovary grows into the fruit.

MCQs & Assertion–Reason

1. Reproduction in which a single parent is involved is called:

(a) sexual    (b) asexual    (c) cross    (d) bisexual

2. The transfer of pollen from the anther to the stigma is called:

(a) fertilisation    (b) pollination    (c) germination    (d) budding

3. The fusion of male and female gametes forms a:

(a) seed    (b) fruit    (c) zygote    (d) bud

4. Which method produces genetically identical plants?

(a) cross-pollination    (b) tissue culture    (c) seed formation    (d) sexual reproduction

5. Yeast reproduces asexually by:

(a) budding    (b) pollination    (c) fertilisation    (d) grafting

6. The male reproductive part of a flower is the:

(a) carpel    (b) stigma    (c) stamen    (d) ovary

7. After fertilisation, the ovule develops into the:

(a) fruit    (b) seed    (c) flower    (d) stigma

8. The shedding of the uterus lining is called:

(a) ovulation    (b) fertilisation    (c) menstruation    (d) implantation

9. Sexual reproduction leads to:

(a) identical offspring    (b) variation in offspring    (c) no offspring    (d) only female offspring

10. Cross-pollination is best brought about by:

(a) closed flowers    (b) pollinators such as bees    (c) self-pollen    (d) tissue culture

Answer key: 1-(b), 2-(b), 3-(c), 4-(b), 5-(a), 6-(c), 7-(b), 8-(c), 9-(b), 10-(b).

For each Assertion–Reason question, choose: (A) Both true and the Reason correctly explains the Assertion; (B) Both true but the Reason is not the correct explanation; (C) Assertion true, Reason false; (D) Assertion false, Reason true.

A-R 1. Assertion: Asexual reproduction produces identical offspring.

Reason: Only one parent is involved and there is no fusion of gametes.

A-R 2. Assertion: Cross-pollination increases genetic variation.

Reason: It brings together genetic material from two different plants.

A-R 3. Assertion: Sexual reproduction helps a species adapt to changing conditions.

Reason: It produces variation among the offspring.

A-R 4. Assertion: Tissue culture is used to grow plants from seeds.

Reason: Seeds are formed only by sexual reproduction.

A-R 5. Assertion: Night-blooming flowers are usually white.

Reason: White flowers are easily seen by night pollinators in dim light.

Answer key: 1-(A), 2-(A), 3-(A), 4-(D), 5-(A).

Quick Revision Summary

  • Reproduction lets a species continue and passes characteristics to the next generation.
  • Asexual = one parent, identical clones; sexual = two parents, variation.
  • Pollination (pollen to stigma) is followed by fertilisation (gamete fusion) to form a zygote.
  • Self-pollination (same plant) vs cross-pollination (different plant, more variation).
  • Vegetative propagation and tissue culture quickly make many identical plants.
  • The menstrual cycle prepares the uterus; it stops during pregnancy.

Real-life Applications

This biology shapes farming and health: grafting, cuttings and tissue culture produce uniform, high-yielding crops; encouraging pollinators (like the beekeeping in Q12) boosts fruit yield; banana, potato and sugarcane are grown by vegetative propagation; and understanding the menstrual cycle and reproduction is the basis of human reproductive health.

How to score full marks in this chapter

Keep the steps in order — pollination, then fertilisation, then zygote, then seed/fruit. Link “identical offspring” to asexual reproduction and “variation” to sexual reproduction. For experiment questions, clearly name the variable that is changed and the variables kept the same.

Frequently Asked Questions

What is Class 9 Science Exploration Chapter 11 about?

Reproduction — why organisms reproduce, asexual and sexual reproduction, vegetative propagation and tissue culture, pollination and fertilisation in plants, and human reproduction including the menstrual cycle.

What is the difference between asexual and sexual reproduction?

Asexual reproduction uses one parent and gives identical offspring; sexual reproduction uses two parents and the fusion of gametes, producing variation.

What is the difference between self- and cross-pollination?

Self-pollination transfers pollen within the same flower or plant; cross-pollination transfers pollen to a different plant of the same species, increasing variation.

Are these Class 9 Science Exploration Chapter 11 solutions free?

Yes. All solutions are free and follow the official NCERT Exploration textbook for 2026–27.

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