Class 10th Science Chapter 7 – How Do Organisms Reproduce? | Pollination and Fertilisation in Plants

How Do Organisms Reproduce?

Pollination and Fertilisation in Plants | Class 10 Science | CBSE + Foundation + Competitive

🌸 Pollination and Fertilisation in Plants

1. Introduction – परिचय

English:
Sexual reproduction in flowering plants involves the formation and fusion of male and female gametes. The flower is the reproductive structure of a flowering plant. Pollination transfers pollen grains from the anther to the stigma, while fertilisation involves the fusion of male and female gametes.

हिन्दी:
फूल वाले पौधों में लैंगिक जनन में नर तथा मादा युग्मकों का निर्माण और उनका संलयन होता है। फूल आवृतबीजी पौधों की प्रजनन संरचना है। परागण में परागकणों का परागकोष से वर्तिकाग्र तक स्थानांतरण होता है, जबकि निषेचन में नर और मादा युग्मकों का संलयन होता है।

Anther → Pollen Grain → Stigma → Pollen Tube → Ovule → Fertilisation → Zygote → Embryo

2. What is Pollination? – परागण क्या है?

English:
Pollination is the transfer of pollen grains from the anther to the stigma of a flower. हिन्दी:
परागण वह प्रक्रिया है जिसमें परागकण परागकोष से वर्तिकाग्र तक पहुँचते हैं।

Important: Pollination occurs before fertilisation.
महत्वपूर्ण: परागण निषेचन से पहले होता है।

3. Types of Pollination – परागण के प्रकार

Type	English Explanation	हिन्दी
Self-Pollination	Pollen is transferred to the stigma of the same flower or another flower of the same plant.	परागकण उसी फूल या उसी पौधे के दूसरे फूल के वर्तिकाग्र तक पहुँचते हैं।
Cross-Pollination	Pollen is transferred from one plant to the stigma of a flower on another plant of the same species.	एक पौधे के परागकण उसी प्रजाति के दूसरे पौधे के फूल के वर्तिकाग्र तक पहुँचते हैं।

4. Self-Pollination – स्वपरागण

Features:

• Usually occurs within the same plant.
• Does not necessarily require another plant of the same species.
• Maintains many parental characteristics.
• Genetic variation is generally less than in cross-pollination.

हिन्दी:

• आमतौर पर एक ही पौधे में होता है।
• दूसरे पौधे की आवश्यकता नहीं होती।
• पौधे के कई पैतृक गुण बने रहते हैं।
• क्रॉस-परागण की तुलना में आनुवंशिक विविधता सामान्यतः कम होती है।

5. Cross-Pollination – पर-परागण

English:
Cross-pollination is the transfer of pollen grains from the anther of one plant to the stigma of another plant of the same species.

हिन्दी:
पर-परागण में एक पौधे के परागकोष से परागकण उसी प्रजाति के दूसरे पौधे के फूल के वर्तिकाग्र तक पहुँचते हैं।

Cross-pollination usually promotes genetic variation.
पर-परागण सामान्यतः आनुवंशिक विविधता को बढ़ावा देता है।

6. Agents of Pollination – परागण के माध्यम

Agent	Examples / Features	हिन्दी
Wind	Light and dry pollen; commonly produced in large quantity.	हल्के तथा सूखे परागकण बड़ी संख्या में बन सकते हैं।
Water	Occurs in some aquatic plants.	कुछ जलीय पौधों में जल परागण का माध्यम हो सकता है।
Insects	Bees, butterflies and other insects carry pollen.	मधुमक्खियाँ तथा तितलियाँ परागकणों को एक फूल से दूसरे फूल तक ले जा सकती हैं।
Animals	Birds and other animals can act as pollinating agents.	पक्षी तथा अन्य जीव भी परागण में सहायता कर सकते हैं।

7. What Happens After Pollination?

English:
After a compatible pollen grain reaches the stigma, it may germinate and form a pollen tube. The pollen tube grows through the style towards the ovary and reaches an ovule.

हिन्दी:
उपयुक्त परागकण के वर्तिकाग्र पर पहुँचने के बाद वह अंकुरित होकर परागनलिका बना सकता है। परागनलिका वर्तिका से होकर अंडाशय की ओर बढ़ती है और एक बीजांड तक पहुँचती है।

Pollen Grain → Germination → Pollen Tube → Style → Ovary → Ovule

8. Pollen Tube – परागनलिका

English:
The pollen tube provides a pathway for the male reproductive cells carried by the pollen grain to reach the ovule.

हिन्दी:
परागनलिका परागकण द्वारा ले जाए जा रहे नर जनन कोशिकाओं को बीजांड तक पहुँचने का मार्ग प्रदान करती है।

9. Fertilisation – निषेचन

English:
Fertilisation is the fusion of male and female gametes to form a zygote.

हिन्दी:
निषेचन वह प्रक्रिया है जिसमें नर तथा मादा युग्मकों का संलयन होकर युग्मनज (Zygote) बनता है।

Male Gamete + Female Gamete → Zygote

10. Site of Fertilisation – निषेचन का स्थान

In flowering plants, fertilisation occurs inside the ovule, which is present inside the ovary.

आवृतबीजी पौधों में निषेचन बीजांड के अंदर होता है। बीजांड अंडाशय के अंदर उपस्थित होता है।

Flower → Ovary → Ovule → Female Gamete

11. Animated Pollination and Fertilisation Diagram

12. Zygote Formation – युग्मनज का निर्माण

After fertilisation, the fertilised egg is called a zygote.

निषेचन के बाद निषेचित अंडाणु को युग्मनज (Zygote) कहा जाता है।

Male Gamete + Female Gamete ↓ Zygote ↓ Embryo ↓ Seed

13. Changes After Fertilisation – निषेचन के बाद परिवर्तन

Structure	After Fertilisation	हिन्दी
Zygote	Develops into embryo	युग्मनज भ्रूण में विकसित होता है।
Ovule	Generally develops into seed	बीजांड सामान्यतः बीज में विकसित होता है।
Ovary	Generally develops into fruit	अंडाशय सामान्यतः फल में विकसित होता है।
Ovary wall	Forms fruit wall / pericarp	अंडाशय की भित्ति फलभित्ति में विकसित हो सकती है।

14. Pollination vs Fertilisation

Pollination	Fertilisation
Transfer of pollen grains.	Fusion of male and female gametes.
Occurs between anther and stigma.	Occurs inside the ovule.
Occurs before fertilisation.	Occurs after successful pollination.
Does not directly form a zygote.	Produces a zygote.

15. Importance of Pollination

• It brings pollen grains to the stigma.
• It makes sexual reproduction possible in flowering plants.
• It enables the male reproductive cells to reach the female reproductive structure.
• Cross-pollination can increase genetic variation.
• It is an important step before fertilisation.

हिन्दी:

• परागकणों को वर्तिकाग्र तक पहुँचाता है।
• फूल वाले पौधों में लैंगिक जनन को संभव बनाता है।
• नर जनन कोशिकाओं को मादा जनन संरचना तक पहुँचने में सहायता करता है।
• पर-परागण आनुवंशिक विविधता बढ़ा सकता है।
• यह निषेचन से पहले की महत्वपूर्ण प्रक्रिया है।

16. Importance of Fertilisation

Fertilisation:

• Produces a zygote.
• Restores the diploid chromosome number.
• Starts development of a new organism.
• Combines genetic material from male and female parents.

17. Important Terms – महत्वपूर्ण शब्द

Term	Meaning
Pollen Grain	Structure carrying male reproductive cells.
Anther	Part of stamen where pollen grains are produced.
Stigma	Sticky receptive part of carpel that receives pollen.
Style	Part connecting stigma with ovary.
Ovary	Part containing ovules.
Ovule	Structure containing the female reproductive apparatus.
Pollination	Transfer of pollen from anther to stigma.
Fertilisation	Fusion of male and female gametes.
Zygote	Cell formed after fertilisation.

18. CBSE Important Points – बोर्ड परीक्षा के लिए

⭐ Golden Points:

1. Pollination occurs before fertilisation.
2. Anther produces pollen grains.
3. Stigma receives pollen grains.
4. Pollen tube grows through the style.
5. Fertilisation occurs inside the ovule.
6. Male gamete fuses with female gamete.
7. Zygote is formed after fertilisation.
8. Zygote develops into embryo.
9. Ovule generally develops into seed.
10. Ovary generally develops into fruit.
11. Cross-pollination promotes genetic variation.

19. 30 MCQs – NEET/Foundation/CBSE Level

Q1. Pollination is the transfer of pollen grains from:

A) Ovule to ovary

B) Anther to stigma

C) Stigma to anther

D) Ovary to stigma

Answer: B

Q2. The part of the flower that produces pollen grains is:

A) Stigma

B) Style

C) Anther

D) Ovary

Answer: C

Q3. Fertilisation is the fusion of:

A) Two pollen grains

B) Male and female gametes

C) Two ovules

D) Two zygotes

Answer: B

Q4. Fertilisation in flowering plants takes place inside the:

A) Anther

B) Stigma

C) Ovule

D) Petal

Answer: C

Q5. The structure that connects stigma and ovary is:

A) Filament

B) Style

C) Sepal

D) Anther

Answer: B

Q6. Cross-pollination generally increases:

A) Genetic variation

B) Identical offspring

C) Vegetative growth only

D) Water absorption

Answer: A

Q7. After fertilisation, the zygote develops into:

A) Pollen grain

B) Embryo

C) Stigma

D) Anther

Answer: B

Q8. The ovule generally develops into:

A) Fruit

B) Seed

C) Petal

D) Stigma

Answer: B

Q9. The ovary generally develops into:

A) Seed

B) Pollen

C) Fruit

D) Embryo

Answer: C

Q10. Which of the following can act as an agent of pollination?

A) Wind

B) Insects

C) Water

D) All of these

Answer: D

Q11. Which process occurs first?

A) Zygote formation

B) Fertilisation

C) Pollination

D) Embryo formation

Answer: C

Q12. The pollen tube usually grows through the:

A) Style

B) Anther

C) Filament

D) Petal

Answer: A

Q13. The receptive surface of the carpel is the:

A) Ovary

B) Stigma

C) Ovule

D) Filament

Answer: B

Q14. Self-pollination may occur between:

A) Flowers of different species

B) Flowers of the same plant

C) Animals only

D) Roots of two plants

Answer: B

Q15. Which structure contains ovules?

A) Ovary

B) Anther

C) Stigma

D) Filament

Answer: A

Q16. Which event directly produces a zygote?

A) Pollination

B) Germination

C) Fertilisation

D) Seed dispersal

Answer: C

Q17. Pollen grains are produced in the:

A) Ovule

B) Anther

C) Ovary

D) Style

Answer: B

Q18. Which is a major advantage of cross-pollination?

A) No genetic variation

B) Increased genetic variation

C) No fertilisation

D) Prevention of seed formation

Answer: B

Q19. The male reproductive cells are carried by:

A) Pollen grain

B) Ovary

C) Sepal

D) Petal

Answer: A

Q20. The female reproductive cell in a flower is present in the:

A) Anther

B) Ovule

C) Filament

D) Petal

Answer: B

Q21. Which sequence is correct?

A) Fertilisation → Pollination → Zygote

B) Pollination → Pollen tube → Fertilisation → Zygote

C) Zygote → Pollination → Fertilisation

D) Ovule → Anther → Stigma

Answer: B

Q22. The main function of stigma is to:

A) Produce ovules

B) Receive pollen grains

C) Produce fruits

D) Produce seeds directly

Answer: B

Q23. Wind-pollinated flowers commonly produce:

A) Very few heavy pollen grains

B) Large amounts of light pollen

C) No pollen

D) Only water

Answer: B

Q24. A pollen tube helps in:

A) Fruit colour formation

B) Transport of male reproductive cells towards ovule

C) Photosynthesis

D) Water absorption by roots

Answer: B

Q25. The product of fusion of gametes is called:

A) Embryo

B) Zygote

C) Seed coat

D) Pollen tube

Answer: B

Q26. Which process is essential for sexual reproduction in flowering plants?

A) Pollination followed by fertilisation

B) Only photosynthesis

C) Only transpiration

D) Only germination

Answer: A

Q27. Which part of the flower is associated with female reproduction?

A) Androecium

B) Gynoecium

C) Petal only

D) Sepal only

Answer: B

Q28. Fertilisation results in the formation of:

A) Zygote

B) Pollen grain

C) Stigma

D) Anther

Answer: A

Q29. Which statement is correct?

A) Pollination and fertilisation are the same process.

B) Pollination occurs after zygote formation.

C) Pollination transfers pollen while fertilisation fuses gametes.

D) Fertilisation occurs in the anther.

Answer: C

Q30. Which structure generally becomes the fruit after fertilisation?

A) Ovary

B) Ovule

C) Anther

D) Stigma

Answer: A

20. 30 Subjective Questions with Answers

2 Marks Q1. Define pollination.

Pollination is the transfer of pollen grains from anther to stigma.
परागण परागकोष से वर्तिकाग्र तक परागकणों के स्थानांतरण की प्रक्रिया है।

2 Marks Q2. What is fertilisation?

Fertilisation is the fusion of male and female gametes to form a zygote.

2 Marks Q3. Name the male reproductive part of a flower.

The male reproductive part is the androecium, consisting of stamens.

2 Marks Q4. Name the female reproductive part of a flower.

The female reproductive part is the gynoecium, consisting of carpels/pistils.

2 Marks Q5. What is a zygote?

A zygote is the cell formed by fusion of male and female gametes.

3 Marks Q6. Differentiate between self-pollination and cross-pollination.

Self-pollination occurs within the same flower or same plant, whereas cross-pollination occurs between flowers on different plants of the same species. Cross-pollination generally produces greater genetic variation.

3 Marks Q7. What is the role of stigma?

The stigma is the receptive part of the carpel. It receives pollen grains and provides a suitable surface for their germination.

3 Marks Q8. Explain the role of pollen tube.

The pollen tube grows from a germinating pollen grain through the stigma and style towards the ovary. It provides a pathway for the male reproductive cells to reach the ovule.

3 Marks Q9. Name three agents of pollination.

Wind, water and insects are three common agents of pollination.

3 Marks Q10. What happens to the zygote after fertilisation?

The zygote undergoes repeated cell divisions and develops into an embryo.

4 Marks Q11. Explain the process of pollination.

Pollination involves:

1. Production of pollen grains in the anther.
2. Transfer of pollen grains to the stigma.
3. Transfer may occur by wind, water, insects or animals.
4. Compatible pollen can germinate on the stigma and form a pollen tube.

4 Marks Q12. Explain fertilisation in flowering plants.

After pollination, the pollen grain germinates on the stigma. A pollen tube grows through the style into the ovary and reaches an ovule. Male reproductive cells are delivered to the female reproductive cell, and fusion produces a zygote.

4 Marks Q13. Give four differences between pollination and fertilisation.

Pollination	Fertilisation
Transfer of pollen	Fusion of gametes
Anther to stigma	Inside ovule
Occurs first	Occurs later
No zygote directly	Zygote is formed

4 Marks Q14. Explain why cross-pollination is important.

Cross-pollination transfers pollen between different plants of the same species. It combines genetic material from different parents and generally increases genetic variation, which can contribute to adaptation and evolution.

4 Marks Q15. Describe the changes occurring after fertilisation.

The zygote develops into an embryo. The ovule generally develops into a seed and the ovary generally develops into a fruit. Other floral parts may wither or fall off.

5 Marks Q16. Explain the complete sequence from pollination to seed formation.

Pollen grains are transferred from anther to stigma. A compatible pollen grain germinates and forms a pollen tube. The tube grows through the style towards the ovary and reaches an ovule. Male and female gametes fuse to form a zygote. The zygote develops into an embryo and the ovule generally develops into a seed.

5 Marks Q17. Explain self-pollination and cross-pollination with their advantages.

Self-pollination occurs within the same flower or plant and tends to preserve parental characteristics. Cross-pollination occurs between different plants of the same species and generally increases genetic variation. Cross-pollination can therefore provide greater variation among offspring.

5 Marks Q18. Explain the role of anther, stigma, style and ovary.

Anther produces pollen grains. Stigma receives pollen grains. Style connects stigma to ovary and provides a path for pollen tube growth. Ovary contains ovules in which the female reproductive structure is present.

5 Marks Q19. Explain how pollinating agents help flowering plants.

Wind, water, insects, birds and other animals can transfer pollen grains from anther to stigma. Insects and animals often carry pollen while visiting flowers, whereas wind can transport light pollen grains. This transfer makes pollination possible.

5 Marks Q20. Why is fertilisation important in sexual reproduction?

Fertilisation combines genetic material from male and female gametes, produces a zygote and initiates development of a new organism. It also restores the diploid chromosome number after fusion of haploid gametes.

6 Marks Q21. Describe pollination and fertilisation in flowering plants with a flow chart.

Answer:

Anther produces pollen → Pollen reaches stigma → Pollen germination → Pollen tube formation → Pollen tube grows through style → Reaches ovule → Male and female gametes fuse → Zygote formation → Embryo development → Seed formation.

6 Marks Q22. Explain the structure involved in fertilisation of a flower.

The anther produces pollen grains containing male reproductive cells. The stigma receives pollen. The style connects stigma and ovary. The ovary contains ovules. After compatible pollination, a pollen tube grows towards an ovule. The male reproductive cell reaches the female reproductive cell and fertilisation occurs.

6 Marks Q23. Explain the differences between self-pollination and cross-pollination.

Self-Pollination	Cross-Pollination
Same flower or same plant	Different plants of same species
Usually requires less external pollen transfer	Often requires a pollinating agent
Genetic variation generally lower	Genetic variation generally higher
Parental characteristics are more easily maintained	New combinations of characteristics can arise

6 Marks Q24. Explain the role of pollination in sexual reproduction.

Pollination brings pollen grains to the stigma. Compatible pollen grains germinate and form pollen tubes. The pollen tube grows towards an ovule and carries male reproductive cells. These cells can then participate in fertilisation. Thus, pollination is an essential step leading to fertilisation in flowering plants.

6 Marks Q25. Explain changes occurring in a flower after fertilisation.

After fertilisation, the zygote develops into an embryo. The ovule generally develops into a seed and the ovary generally develops into a fruit. The seed contains the developing embryo and is protected by seed coverings. Many other floral parts gradually wither and fall off.

6 Marks Q26. Explain the importance of genetic variation produced through sexual reproduction.

Sexual reproduction combines genetic material from two parents. Cross-pollination can further increase variation. Such variation may help populations survive environmental changes and provides the raw material for natural selection and evolution.

6 Marks Q27. Explain how an insect helps in pollination.

An insect visits a flower to collect nectar or pollen. Pollen grains stick to its body. When it visits another compatible flower, some pollen grains may be deposited on the stigma. This results in pollination and may be followed by fertilisation.

6 Marks Q28. Explain the journey of a pollen grain from anther to ovule.

Pollen is produced in the anther. During pollination it reaches the stigma. If compatible, it germinates and forms a pollen tube. The pollen tube grows through the style into the ovary and reaches an ovule. Male reproductive cells are delivered through this pathway and one can fuse with the female gamete during fertilisation.

6 Marks Q29. Write a detailed note on fertilisation and zygote formation.

Fertilisation is the fusion of male and female gametes. In flowering plants it occurs in the ovule. The fusion produces a diploid zygote. The zygote undergoes cell division and differentiation to form an embryo. The embryo later becomes part of the developing seed.

6 Marks Q30. Explain the complete reproductive process in a flowering plant.

Answer:

A flowering plant produces male reproductive structures in the stamens and female reproductive structures in the carpel. Pollen grains are formed in the anther. Pollination transfers pollen grains to the stigma. A compatible pollen grain germinates and produces a pollen tube. The tube grows through the style towards an ovule in the ovary. Male and female gametes fuse to form a zygote. The zygote develops into an embryo, while the ovule generally develops into a seed and the ovary generally develops into a fruit.

21. HOTS / Competency-Based Questions

HOTS 1: A plant produces many pollen grains but very few seeds. Give one possible reason.

Pollination may be unsuccessful, pollen may not reach a compatible stigma, or fertilisation may fail after pollination.

HOTS 2: Why does removing anthers before pollen release prevent self-pollination?

Removal of anthers prevents pollen grains from being available for transfer from that flower's own anthers to its stigma.

HOTS 3: If pollen reaches the stigma but no pollen tube develops, what may happen?

Fertilisation may not occur because the male reproductive cells may not reach the ovule.

HOTS 4: Why can cross-pollination be beneficial for a population?

It generally increases genetic variation, which may help populations adapt to changing environmental conditions.

22. Diagram Labelling Practice

Label the following:

1. Anther
2. Pollen grain
3. Stigma
4. Style
5. Ovary
6. Ovule
7. Pollen tube
8. Male reproductive cell
9. Female reproductive cell
10. Zygote

23. One-Line Revision – एक लाइन में Revision

🌸 Anther → Pollen
🌸 Stigma → Receives Pollen
🌸 Style → Pollen Tube Pathway
🌸 Ovary → Contains Ovules
🌸 Pollination → Anther to Stigma
🌸 Pollen Tube → Towards Ovule
🌸 Fertilisation → Fusion of Gametes
🌸 Zygote → Embryo
🌸 Ovule → Seed
🌸 Ovary → Fruit

24. Memory Trick – याद रखने की Trick

“A-P-S-P-O-F-Z-E-S-F”

Anther → Pollen → Stigma → Pollen Tube → Ovule → Fertilisation → Zygote → Embryo → Seed → Fruit

25. Final Exam Revision

Most Important Questions:

• What is pollination?
• Differentiate self and cross-pollination.
• What are the agents of pollination?
• Explain pollen tube formation.
• Define fertilisation.
• Where does fertilisation occur?
• What is a zygote?
• What happens to ovule after fertilisation?
• What happens to ovary after fertilisation?
• Explain the complete process from pollination to seed formation.

Class 10th Science Chapter 7 – How Do Organisms Reproduce? | Reproductive Parts of a Flower

🌸 How Do Organisms Reproduce?

Reproductive Parts of a Flower | Class 10 Science | CBSE + Foundation + Competitive

How Do Organisms Reproduce? | Reproductive Parts of a Flower

1. Introduction – परिचय

English:
In flowering plants, the flower is the reproductive structure. A typical flower has four main whorls:

• Calyx
• Corolla
• Androecium
• Gynoecium

Among these, androecium and gynoecium are the main reproductive parts.

हिन्दी:
पुष्पीय पौधों में फूल जनन संरचना है। फूल के चार मुख्य चक्र होते हैं—दलपुंज (Calyx), पंखुड़ी-पुंज (Corolla), पुंकेसर-पुंज (Androecium) और जायांग (Gynoecium)।

2. Four Main Parts/Whorls of a Flower

Whorl	English Name	Main Function
Calyx	Sepals	Protects the developing flower bud
Corolla	Petals	Often attracts pollinators
Androecium	Stamens	Male reproductive part
Gynoecium	Carpel/Pistil	Female reproductive part

3. Animated Diagram – Typical Flower

🌸 Reproductive Parts of a Flower

4. Androecium – Male Reproductive Part

The androecium is the male reproductive whorl of a flower. Its individual units are called stamens. Each stamen generally consists of:

1. Filament
A slender stalk that supports the anther.

2. Anther
The enlarged structure at the top of the filament. It produces pollen grains.

Stamen = Filament + Anther

5. Anther – परागकोष

The anther is the pollen-producing part of the stamen. It contains pollen sacs where pollen grains develop. Pollen grains carry the male reproductive cells/gametes.

Exam Point: Anther → Pollen grains
Filament → Supports anther

6. Filament – तंतु

The filament is the stalk-like part of the stamen. Its major function is to support and position the anther so that pollen can be released and transferred efficiently.

7. Gynoecium – Female Reproductive Part

The gynoecium is the female reproductive whorl of a flower. It may consist of one or more carpels. A carpel/pistil has three main regions:

• Stigma
• Style
• Ovary

Pistil/Carpel = Stigma + Style + Ovary

8. Stigma – वर्तिकाग्र

The stigma is the topmost part of the pistil. Its main function is to receive pollen grains. The stigma is often sticky or has a suitable surface that helps pollen grains adhere and germinate.

9. Style – वर्तिका

The style is the slender region between stigma and ovary. After pollen germination, the pollen tube grows through the style towards the ovary. Therefore, the style provides a pathway for pollen tube growth.

10. Ovary – अंडाशय

The ovary is the basal swollen part of the pistil. It contains one or more ovules. After fertilisation, the ovary generally develops into a fruit.

Ovary → Fruit

11. Ovule – बीजांड

An ovule is present inside the ovary. The female gamete/egg cell is present within the embryo sac of the ovule. After fertilisation, the ovule generally develops into a seed.

Ovule → Seed

12. Reproductive Parts – Complete Comparison

Structure	Part of	Function
Stamen	Androecium	Male reproductive structure
Anther	Stamen	Produces pollen grains
Filament	Stamen	Supports anther
Pistil/Carpel	Gynoecium	Female reproductive structure
Stigma	Pistil	Receives pollen
Style	Pistil	Pathway for pollen tube
Ovary	Pistil	Contains ovules
Ovule	Ovary	Develops into seed after fertilisation

13. Bisexual Flower

A flower containing both stamens and carpels is called a bisexual flower. Examples:

• Hibiscus
• Mustard
• Rose

14. Unisexual Flower

A flower containing either stamens or carpels is called a unisexual flower. Examples include:

• Papaya
• Watermelon
• Maize flowers are unisexual

15. Pollination and Reproductive Parts

Pollination is the transfer of pollen grains from the anther to the stigma. Therefore, two important structures involved are:

Anther → Source of pollen
Stigma → Receiver of pollen

Anther → Pollen → Stigma

16. Fertilisation and Reproductive Parts

After pollination, a compatible pollen grain can germinate on the stigma. A pollen tube grows through the style towards the ovary. The male gametes reach the ovule. Fusion of male and female gametes forms the zygote.

Pollen ↓ Stigma ↓ Pollen Tube ↓ Style ↓ Ovary ↓ Ovule ↓ Fertilisation ↓ Zygote

17. After Fertilisation – Important Changes

Structure Before Fertilisation	Fate After Fertilisation
Zygote	Embryo
Ovule	Seed
Ovary	Fruit
Ovary wall	Generally forms fruit wall/pericarp

18. Most Important Exam Differences

Stamen	Pistil/Carpel
Male reproductive part	Female reproductive part
Consists of filament and anther	Consists of stigma, style and ovary
Produces pollen grains	Contains ovules
Part of androecium	Part of gynoecium

19. 30 MCQs – MCQ Practice

Q1. The reproductive structure of a flowering plant is:

A) Flower

B) Root

C) Leaf

D) Stem

Answer: A) Flower

Q2. The male reproductive part of a flower is:

A) Pistil

B) Stamen

C) Ovary

D) Stigma

Answer: B) Stamen

Q3. The anther is a part of:

A) Pistil

B) Ovary

C) Stamen

D) Sepal

Answer: C) Stamen

Q4. The female reproductive part of a flower is:

A) Anther

B) Filament

C) Stamen

D) Pistil

Answer: D) Pistil

Q5. Pollen grains are produced in:

A) Anther

B) Style

C) Ovary

D) Stigma

Answer: A) Anther

Q6. The filament mainly:

A) Produces ovules

B) Supports the anther

C) Receives pollen

D) Forms fruit

Answer: B) Supports the anther

Q7. Which part receives pollen grains?

A) Ovary

B) Style

C) Stigma

D) Anther

Answer: C) Stigma

Q8. The pollen tube generally grows through the:

A) Anther

B) Filament

C) Petal

D) Style

Answer: D) Style

Q9. Ovules are present inside the:

A) Ovary

B) Anther

C) Filament

D) Petal

Answer: A) Ovary

Q10. After fertilisation, the ovule generally becomes:

A) Fruit

B) Seed

C) Petal

D) Anther

Answer: B) Seed

Q11. After fertilisation, the ovary generally becomes:

A) Seed

B) Pollen

C) Fruit

D) Embryo

Answer: C) Fruit

Q12. A flower containing both stamens and carpels is:

A) Unisexual

B) Sterile

C) Vegetative

D) Bisexual

Answer: D) Bisexual

Q13. Which is a bisexual flower?

A) Hibiscus

B) Papaya

C) Watermelon

D) Male maize flower

Answer: A) Hibiscus

Q14. Which is a unisexual flower?

A) Hibiscus

B) Papaya

C) Mustard

D) Rose

Answer: B) Papaya

Q15. Androecium represents:

A) Female reproductive whorl

B) Protective whorl

C) Male reproductive whorl

D) Petals

Answer: C) Male reproductive whorl

Q16. Gynoecium represents:

A) Male reproductive whorl

B) Petals

C) Sepals

D) Female reproductive whorl

Answer: D) Female reproductive whorl

Q17. The pistil consists of:

A) Stigma, style and ovary

B) Anther and filament

C) Petal and sepal

D) Ovule and anther

Answer: A) Stigma, style and ovary

Q18. The stamen consists of:

A) Stigma and style

B) Anther and filament

C) Ovary and ovule

D) Petal and sepal

Answer: B) Anther and filament

Q19. The structure that contains the female gamete is associated with the:

A) Filament

B) Anther

C) Ovule

D) Petal

Answer: C) Ovule

Q20. Pollination is the transfer of pollen from:

A) Stigma to anther

B) Ovary to ovule

C) Style to stigma

D) Anther to stigma

Answer: D) Anther to stigma

Q21. Which structure is swollen at the base of the pistil?

A) Ovary

B) Style

C) Stigma

D) Filament

Answer: A) Ovary

Q22. The main function of the stigma is:

A) Pollen production

B) Pollen reception

C) Seed storage

D) Fruit formation

Answer: B) Pollen reception

Q23. Which structure supports the anther?

A) Style

B) Stigma

C) Filament

D) Ovary

Answer: C) Filament

Q24. Which structure contains ovules?

A) Anther

B) Filament

C) Stigma

D) Ovary

Answer: D) Ovary

Q25. Which sequence is correct?

A) Anther → Pollen → Stigma

B) Ovary → Pollen → Anther

C) Stigma → Pollen → Anther

D) Ovule → Pollen → Filament

Answer: A) Anther → Pollen → Stigma

Q26. Which structure develops into the embryo after fertilisation?

A) Ovule

B) Zygote

C) Ovary

D) Anther

Answer: B) Zygote

Q27. Which pair is correctly matched?

A) Anther — Female part

B) Ovary — Pollen production

C) Filament — Supports anther

D) Stigma — Produces ovules

Answer: C) Filament — Supports anther

Q28. Which pair is correctly matched?

A) Stigma — Produces pollen

B) Ovary — Produces petals

C) Filament — Contains ovules

D) Ovule — Develops into seed

Answer: D) Ovule — Develops into seed

Q29. Which two structures are directly involved in pollination?

A) Anther and stigma

B) Ovary and ovule

C) Filament and style

D) Sepal and petal

Answer: A) Anther and stigma

Q30. Which statement is correct?

A) Ovary becomes pollen

B) Ovule generally becomes seed

C) Anther becomes fruit

D) Filament becomes embryo

Answer: B) Ovule generally becomes seed

20. 30 Subjective Questions

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

Answer: The male reproductive part is the stamen and the female reproductive part is the pistil/carpel.

2 Marks Q2. Name the two parts of a stamen.

Answer: Anther and filament.

2 Marks Q3. Name the three main parts of a pistil.

Answer: Stigma, style and ovary.

2 Marks Q4. What is the function of anther?

Answer: The anther produces pollen grains containing the male reproductive cells.

2 Marks Q5. What happens to the ovule after fertilisation?

Answer: The ovule generally develops into a seed.

3 Marks Q6. Describe the structure of a stamen.

Answer: A stamen consists of a filament and anther. The filament supports the anther, while the anther produces pollen grains.

3 Marks Q7. Describe the structure of a pistil.

Answer: The pistil consists of stigma, style and ovary. Stigma receives pollen, style provides a pathway for the pollen tube, and ovary contains ovules.

3 Marks Q8. What is the function of stigma?

Answer: Stigma receives pollen grains and provides a suitable surface for pollen adhesion and germination.

3 Marks Q9. What is the function of the style?

Answer: The style connects stigma and ovary and provides the pathway through which the pollen tube grows towards the ovary.

3 Marks Q10. What is the function of the ovary?

Answer: The ovary contains ovules. After fertilisation, it generally develops into a fruit.

4 Marks Q11. Differentiate between stamen and pistil.

Answer: Stamen is the male reproductive part and consists of anther and filament. Pistil is the female reproductive part and consists of stigma, style and ovary.

4 Marks Q12. Explain the functions of anther and filament.

Answer: Anther produces pollen grains. Filament is the stalk that supports the anther and positions it for effective pollen release.

4 Marks Q13. Explain the functions of stigma, style and ovary.

Answer: Stigma receives pollen grains. Style provides a pathway for pollen tube growth. Ovary contains ovules and generally develops into a fruit after fertilisation.

4 Marks Q14. Differentiate between bisexual and unisexual flowers.

Answer: A bisexual flower contains both stamens and carpels, e.g. hibiscus. A unisexual flower contains either stamens or carpels, e.g. papaya.

4 Marks Q15. Explain the relationship between ovary and ovule.

Answer: Ovules are structures present inside the ovary. The female gamete is present within the embryo sac of the ovule. After fertilisation, the ovule generally becomes a seed, while the ovary becomes a fruit.

5 Marks Q16. Draw and label the reproductive parts of a typical flower.

Answer: The diagram should show and label anther, filament, stigma, style, ovary and ovule. Stamen is the male reproductive part, while pistil/carpel is the female reproductive part.

5 Marks Q17. Explain the role of stamen in sexual reproduction.

Answer: The stamen is the male reproductive part. Its anther produces pollen grains. The filament supports the anther. Pollen grains carry the male reproductive cells and participate in fertilisation after reaching a suitable stigma.

5 Marks Q18. Explain the role of pistil in sexual reproduction.

Answer: The pistil consists of stigma, style and ovary. Stigma receives pollen, style provides a route for pollen tube growth, and ovary contains ovules. The female gamete is present within the embryo sac of the ovule.

5 Marks Q19. Explain what happens to flower parts after fertilisation.

Answer: The zygote develops into an embryo. The ovule develops into a seed and the ovary generally develops into a fruit. Other floral parts may wither and fall, although their exact fate can vary.

5 Marks Q20. Explain the role of reproductive parts in pollination and fertilisation.

Answer: The anther produces pollen. Pollination transfers pollen to the stigma. The pollen germinates and the pollen tube grows through the style to the ovary. Male gametes reach the ovule and fertilisation produces the zygote.

6 Marks Q21. Describe all the reproductive parts of a typical flower.

Answer:
1. Stamen: Male reproductive part.
2. Anther: Produces pollen grains.
3. Filament: Supports anther.
4. Pistil/Carpel: Female reproductive part.
5. Stigma: Receives pollen.
6. Style: Provides pathway for pollen tube.
7. Ovary: Contains ovules.

6 Marks Q22. Explain the structure and function of stamen and pistil.

Answer: Stamen consists of filament and anther and represents the male reproductive part. Anther produces pollen grains. Pistil consists of stigma, style and ovary and represents the female reproductive part. Stigma receives pollen, style supports pollen tube growth and ovary contains ovules.

6 Marks Q23. Explain the complete pathway of pollen from anther to ovule.

Answer: Pollen grains are produced in the anther. During pollination, they reach the stigma. A compatible pollen grain germinates and forms a pollen tube. The pollen tube grows through the style into the ovary and reaches the ovule, carrying male gametes.

6 Marks Q24. Explain the changes that occur after fertilisation.

Answer: Fertilisation forms a zygote. The zygote develops into an embryo. The ovule generally develops into a seed and the ovary generally develops into a fruit. The seed can later germinate under suitable conditions to form a new plant.

6 Marks Q25. Differentiate between androecium and gynoecium.

Answer: Androecium is the male reproductive whorl and consists of stamens. Each stamen has anther and filament. Gynoecium is the female reproductive whorl and consists of one or more carpels/pistils, each having stigma, style and ovary.

6 Marks Q26. Explain bisexual and unisexual flowers with examples.

Answer: A bisexual flower has both stamens and carpels in the same flower, e.g. hibiscus. A unisexual flower has either stamens or carpels, e.g. papaya. Thus, bisexual and unisexual flowers differ in the reproductive structures present in a single flower.

6 Marks Q27. Explain how the structure of a flower supports sexual reproduction.

Answer: The anther produces pollen, while the stigma receives it. The style provides a route for pollen tube growth. The ovary contains ovules where the female gamete is located within the embryo sac. These structures together enable pollination, pollen tube growth and fertilisation.

6 Marks Q28. Explain the importance of ovary and ovule in sexual reproduction.

Answer: The ovary is the basal part of the pistil and contains ovules. The ovule contains the embryo sac with the female gamete. Fertilisation occurs within the ovule. After fertilisation, the ovule generally becomes a seed and the ovary becomes a fruit.

6 Marks Q29. Explain the role of stigma, style and ovary during fertilisation.

Answer: Stigma receives pollen grains. A compatible pollen grain germinates and forms a pollen tube. The pollen tube grows through the style and reaches the ovary. The ovary contains ovules, where the male gamete eventually reaches the female gamete for fertilisation.

6 Marks Q30. Write the complete sequence of sexual reproduction using the reproductive parts of a flower.

Answer:
Anther → Pollen production → Stigma → Pollen germination → Pollen tube → Style → Ovary → Ovule → Male gamete + Female gamete → Fertilisation → Zygote → Embryo → Seed → New plant.

21. CBSE Golden Points ⭐

⭐ Flower = reproductive structure of flowering plants.

⭐ Androecium = male reproductive whorl.

⭐ Gynoecium = female reproductive whorl.

⭐ Stamen = Filament + Anther.

⭐ Anther = produces pollen grains.

⭐ Filament = supports anther.

⭐ Pistil/Carpel = Stigma + Style + Ovary.

⭐ Stigma = receives pollen.

⭐ Style = pathway for pollen tube.

⭐ Ovary = contains ovules.

⭐ Ovule = contains embryo sac with female gamete.

⭐ Ovule → Seed.

⭐ Ovary → Fruit.

⭐ Anther → Pollen.

⭐ Anther → Pollen → Stigma → Style → Ovary → Ovule.

22. One-Line Revision 🧠

🌸 Flower → Reproductive Structure

♂ Androecium → Male Whorl

🌼 Stamen → Male Part

🟡 Anther → Pollen

🌿 Filament → Supports Anther

♀ Gynoecium → Female Whorl

🎯 Stigma → Receives Pollen

🌱 Style → Pollen Tube Path

🥚 Ovary → Contains Ovules

🟡 Ovule → Seed

🍎 Ovary → Fruit

🧬 Fertilisation → Zygote

23. Diagram Labelling Practice

Important labels to learn:

1. Petal
2. Sepal
3. Anther
4. Filament
5. Stigma
6. Style
7. Ovary
8. Ovule
9. Stamen
10. Pistil/Carpel

24. Super-Fast Memory Trick 🚀

STAMEN = FA
Filament + Anther

PISTIL = SSO
Stigma + Style + Ovary

A → P → S → O → O

Anther → Pollen → Stigma → Ovary → Ovule

Ovule → Seed
Ovary → Fruit

25. Final Exam Revision

🌸 FLOWER ↓ ANDROECIUM
Stamen
Filament + Anther
Anther → Pollen ↓ GYNOECIUM
Pistil/Carpel
Stigma + Style + Ovary
Ovary → Ovules ↓ Pollination ↓ Pollen Tube ↓ Fertilisation ↓ Zygote ↓ Embryo ↓ Ovule → Seed
Ovary → Fruit

Class 10th Science Chapter 7 – How Do Organisms Reproduce? | Sexual Reproduction in Plants

🌸 How Do Organisms Reproduce?

Sexual Reproduction in Plants | Class 10 Science | CBSE + Foundation + Competitive

How Do Organisms Reproduce? | Sexual Reproduction in Plants

1. Introduction – परिचय

English:
Sexual reproduction involves the formation of male and female gametes and their fusion to form a zygote. In flowering plants, the flower is the reproductive structure. Sexual reproduction produces variation because genetic material comes from two gametes.

हिन्दी:
लैंगिक जनन में नर तथा मादा युग्मकों का निर्माण और उनका संलयन शामिल होता है, जिससे युग्मनज (zygote) बनता है। आवृतबीजी पौधों में फूल जनन संरचना है।

2. Flower – The Reproductive Organ

A typical flower contains four main whorls:

• Calyx – sepals
• Corolla – petals
• Androecium – male reproductive part
• Gynoecium – female reproductive part

The reproductive parts are the stamen and pistil/carpel.

🌸 Animated Structure of a Flower

3. Male Reproductive Part – Stamen

The stamen is the male reproductive part of a flower. It consists mainly of:

• Filament – stalk that supports the anther.
• Anther – produces pollen grains.

Pollen grains contain the male reproductive cells/gametes.

4. Female Reproductive Part – Pistil/Carpel

The pistil or carpel is the female reproductive part. It has three main parts:

Part	Function
Stigma	Receives pollen grains
Style	Connects stigma with ovary and provides a pathway for pollen tube growth
Ovary	Contains ovules

After fertilisation:
Ovule → Seed
Ovary → Fruit

5. Bisexual and Unisexual Flowers

Type	Meaning	Example
Bisexual flower	Contains both stamens and carpels	Hibiscus, mustard
Unisexual flower	Contains either stamens or carpels	Papaya, watermelon

6. Pollination – परागण

Pollination is the transfer of pollen grains from the anther to the stigma of a flower. There are two major types:

• Self-pollination
• Cross-pollination

7. Self-Pollination

Self-pollination occurs when pollen reaches the stigma of the same flower or another flower on the same plant. It does not require pollen transfer between different plants.

Same Flower / Same Plant → Pollen Transfer → Stigma

8. Cross-Pollination

Cross-pollination occurs when pollen grains are transferred from a flower of one plant to the stigma of a flower on another plant of the same species. Agents such as insects, wind and other animals may help in pollination.

Plant A → Pollen → Plant B → Stigma

9. Agents of Pollination

Agent	Typical Feature
Wind	Light, dry pollen; exposed anthers/stigmas in many wind-pollinated flowers
Insects	Flowers may have colour, scent and nectar
Animals	Can transfer pollen while visiting flowers

10. Pollen Tube Formation

After a compatible pollen grain lands on the stigma, it can germinate and produce a pollen tube. The pollen tube grows through the style towards the ovary. It carries the male gametes towards the ovule.

🌱 Animated Pollen Tube Growth

11. Fertilisation – निषेचन

Fertilisation is the fusion of male and female gametes to form a zygote. In flowering plants, male gametes are delivered through the pollen tube to the ovule. The male gamete fuses with the female gamete (egg cell).

Male Gamete + Female Gamete → Zygote

12. Double Fertilisation – द्विनिषेचन

A special feature of flowering plants is double fertilisation. One male gamete fuses with the egg to form the diploid zygote. The other male gamete fuses with the two polar nuclei to form the triploid primary endosperm nucleus. Therefore:

Syngamy:
Male gamete + Egg → Zygote (2n)

Triple fusion:
Male gamete + Two polar nuclei → Primary endosperm nucleus (3n)

Competitive/Foundation Point:
Double fertilisation is characteristic of flowering plants (angiosperms). It involves syngamy + triple fusion.

13. What Happens After Fertilisation?

Before Fertilisation	After Fertilisation
Ovule	Seed
Ovary	Fruit
Zygote	Embryo
Fertilisation	Seed formation begins

14. Seed Formation

After fertilisation, the zygote develops into an embryo. The ovule develops into a seed. The seed contains the embryo and stored food in varying forms depending on the plant. Under suitable conditions, the seed germinates to produce a new plant.

Zygote → Embryo → Seed → Germination → New Plant

15. Fruit Formation

After fertilisation, the ovary develops into the fruit. The wall of the ovary generally develops into the pericarp, which forms the fruit wall. Fruits protect seeds and help in their dispersal.

16. Seed Germination

When a viable seed receives suitable conditions such as water, oxygen and appropriate temperature, it may germinate. The embryo resumes growth. The radicle generally develops into the primary root and the plumule develops into the shoot.

Seed + Water + Oxygen + Suitable Temperature → Germination → Seedling

17. Sexual Reproduction Produces Variation

Sexual reproduction involves genetic material from two gametes. During sexual reproduction, genetic combinations can differ among offspring. Therefore, sexual reproduction generates variation. Variation is important for adaptation and evolution of populations.

18. Advantages of Sexual Reproduction in Plants

• Produces genetic variation.
• Variation may help populations adapt to changing environments.
• Creates new combinations of characteristics.
• Supports evolution over generations.

19. Sexual vs Asexual Reproduction

Feature	Sexual Reproduction	Asexual Reproduction
Gametes	Involved	Generally not involved
Fertilisation	Occurs	Absent
Parents	Genetic material from two gametes	Usually one parent
Variation	More genetic variation	Generally less variation
Example in plants	Flowering plants producing seeds	Vegetative propagation

20. Complete Sequence – Flowering Plant Reproduction

Flower ↓ Anther Produces Pollen ↓ Pollination ↓ Pollen Germination ↓ Pollen Tube Growth ↓ Male Gametes Reach Ovule ↓ Fertilisation ↓ Zygote ↓ Embryo ↓ Seed ↓ Germination ↓ New Plant

21. 30 MCQs – MCQ Practice

Q1. The reproductive structure of a flowering plant is:

A) Flower

B) Root

C) Leaf

D) Stem

Answer: A) Flower

Q2. The male reproductive part of a flower is:

A) Pistil

B) Stamen

C) Ovary

D) Stigma

Answer: B) Stamen

Q3. Pollen grains are produced in:

A) Filament

B) Stigma

C) Anther

D) Ovary

Answer: C) Anther

Q4. The female reproductive part of a flower is:

A) Anther

B) Filament

C) Stamen

D) Pistil/Carpel

Answer: D) Pistil/Carpel

Q5. The stigma mainly functions to:

A) Receive pollen grains

B) Produce ovules

C) Produce seeds

D) Store food

Answer: A) Receive pollen grains

Q6. Ovules are present inside the:

A) Anther

B) Ovary

C) Filament

D) Stigma

Answer: B) Ovary

Q7. Transfer of pollen from anther to stigma is called:

A) Fertilisation

B) Germination

C) Pollination

D) Fragmentation

Answer: C) Pollination

Q8. Pollination between flowers of two different plants of the same species is:

A) Self-pollination

B) Budding

C) Vegetative propagation

D) Cross-pollination

Answer: D) Cross-pollination

Q9. The tube formed by a germinating pollen grain is called:

A) Pollen tube

B) Root tube

C) Seed tube

D) Ovule tube

Answer: A) Pollen tube

Q10. The pollen tube generally grows through the:

A) Anther

B) Style

C) Petal

D) Sepal

Answer: B) Style

Q11. Fusion of male and female gametes produces:

A) Seed

B) Fruit

C) Zygote

D) Pollen

Answer: C) Zygote

Q12. Double fertilisation is characteristic of:

A) Fungi

B) Algae

C) Bryophytes

D) Flowering plants

Answer: D) Flowering plants

Q13. Syngamy results in the formation of:

A) Zygote

B) Endosperm

C) Pollen tube

D) Fruit wall

Answer: A) Zygote

Q14. Triple fusion produces:

A) Zygote

B) Primary endosperm nucleus

C) Embryo

D) Seed coat

Answer: B) Primary endosperm nucleus

Q15. The ovule develops into:

A) Fruit

B) Pollen

C) Seed

D) Petal

Answer: C) Seed

Q16. After fertilisation, the ovary generally develops into:

A) Seed

B) Embryo

C) Pollen tube

D) Fruit

Answer: D) Fruit

Q17. The zygote develops into:

A) Embryo

B) Pollen grain

C) Stigma

D) Anther

Answer: A) Embryo

Q18. A flower containing both stamens and carpels is:

A) Unisexual

B) Bisexual

C) Sterile

D) Vegetative

Answer: B) Bisexual

Q19. Which is an example of a unisexual flower?

A) Hibiscus

B) Mustard

C) Papaya

D) Rose

Answer: C) Papaya

Q20. Which is an example of a bisexual flower?

A) Papaya

B) Watermelon

C) Maize

D) Hibiscus

Answer: D) Hibiscus

Q21. The stalk of the stamen is called:

A) Filament

B) Style

C) Stigma

D) Ovule

Answer: A) Filament

Q22. Which structure connects stigma and ovary?

A) Filament

B) Style

C) Anther

D) Sepal

Answer: B) Style

Q23. Which process introduces greater genetic variation?

A) Binary fission

B) Budding

C) Sexual reproduction

D) Vegetative propagation

Answer: C) Sexual reproduction

Q24. Which is NOT normally a requirement for seed germination?

A) Water

B) Oxygen

C) Suitable temperature

D) Fertilisation at the time of germination

Answer: D) Fertilisation at the time of germination

Q25. The male gametes in flowering plants are delivered to the ovule through:

A) Pollen tube

B) Sepal

C) Petal

D) Filament

Answer: A) Pollen tube

Q26. The triploid product of triple fusion is:

A) Zygote

B) Primary endosperm nucleus

C) Embryo

D) Pollen grain

Answer: B) Primary endosperm nucleus

Q27. Which combination is correct?

A) Anther — receives pollen

B) Ovary — produces pollen

C) Ovule — develops into seed

D) Filament — contains ovules

Answer: C) Ovule — develops into seed

Q28. Which structure usually becomes the fruit after fertilisation?

A) Ovule

B) Stigma

C) Anther

D) Ovary

Answer: D) Ovary

Q29. Which sequence is correct?

A) Pollination → Pollen tube → Fertilisation → Seed

B) Fertilisation → Pollination → Pollen tube → Seed

C) Seed → Pollination → Fertilisation → Flower

D) Pollen tube → Pollination → Seed → Fertilisation

Answer: A) Pollination → Pollen tube → Fertilisation → Seed

Q30. The main biological significance of sexual reproduction is:

A) No variation

B) Generation of variation

C) Absence of gametes

D) Absence of fertilisation

Answer: B) Generation of variation

22. 30 Subjective Questions

2 Marks Q1. What is sexual reproduction?

Answer: Sexual reproduction involves the formation of male and female gametes and their fusion to form a zygote.

2 Marks Q2. Name the male and female reproductive parts of a flower.

Answer: The male reproductive part is the stamen and the female reproductive part is the pistil/carpel.

2 Marks Q3. What is pollination?

Answer: Pollination is the transfer of pollen grains from the anther to the stigma.

2 Marks Q4. What is fertilisation?

Answer: Fertilisation is the fusion of male and female gametes to form a zygote.

2 Marks Q5. What happens to the ovule and ovary after fertilisation?

Answer: The ovule develops into a seed and the ovary generally develops into a fruit.

3 Marks Q6. Describe the structure of a stamen.

Answer: A stamen consists of a filament and anther. The filament supports the anther. The anther produces pollen grains containing male reproductive cells.

3 Marks Q7. Describe the structure of a pistil.

Answer: The pistil consists of stigma, style and ovary. The stigma receives pollen, the style provides a path for the pollen tube and the ovary contains ovules.

3 Marks Q8. Differentiate self-pollination and cross-pollination.

Answer: Self-pollination involves pollen transfer within the same flower or same plant. Cross-pollination involves transfer from one plant to another plant of the same species.

3 Marks Q9. What is a bisexual flower? Give one example.

Answer: A bisexual flower contains both stamens and carpels. Hibiscus is an example.

3 Marks Q10. What is a unisexual flower? Give one example.

Answer: A unisexual flower contains either stamens or carpels. Papaya is an example.

4 Marks Q11. Explain the process of pollination.

Answer: Pollen grains produced in the anther are transferred to the stigma. This transfer may occur within the same flower/plant or between different plants of the same species. Wind, insects and animals can act as pollinating agents.

4 Marks Q12. Explain pollen tube formation.

Answer: After a compatible pollen grain lands on the stigma, it germinates and forms a pollen tube. The tube grows through the style towards the ovary and carries male gametes to the ovule.

4 Marks Q13. Explain the changes that occur after fertilisation.

Answer: The zygote develops into an embryo. The ovule becomes a seed and the ovary generally becomes a fruit. The seed contains the developing embryo and stored food.

4 Marks Q14. Differentiate bisexual and unisexual flowers.

Answer: Bisexual flowers contain both stamens and carpels, e.g. hibiscus. Unisexual flowers contain either stamens or carpels, e.g. papaya.

4 Marks Q15. Explain the role of stigma, style and ovary.

Answer: Stigma receives pollen grains. Style connects stigma to ovary and supports pollen tube growth. Ovary contains ovules and after fertilisation generally develops into a fruit.

5 Marks Q16. Draw and explain the structure of a typical flower.

Answer: A typical flower has sepals, petals, stamens and carpels. Stamen consists of filament and anther. Carpel consists of stigma, style and ovary. The ovary contains ovules.

5 Marks Q17. Explain sexual reproduction in flowering plants.

Answer: The anther produces pollen grains. Pollination transfers pollen to the stigma. A pollen tube develops and grows through the style to the ovule. Male gametes reach the female gamete and fertilisation occurs. The zygote forms an embryo, while ovule becomes seed and ovary becomes fruit.

5 Marks Q18. Explain double fertilisation.

Answer: In flowering plants, one male gamete fuses with the egg to form the diploid zygote. The other male gamete fuses with two polar nuclei to form the triploid primary endosperm nucleus. These two fusion events constitute double fertilisation.

5 Marks Q19. Explain the importance of sexual reproduction.

Answer: Sexual reproduction creates new combinations of genetic material and produces variation. Variation can help organisms adapt to changing environments and contributes to evolution.

5 Marks Q20. Explain seed formation and germination.

Answer: After fertilisation, the ovule develops into a seed containing an embryo. Under suitable conditions of water, oxygen and temperature, the embryo resumes growth. The radicle forms the root and the plumule forms the shoot.

6 Marks Q21. Describe sexual reproduction in a flowering plant from pollination to seed formation.

Answer: Pollen grains are transferred from anther to stigma. A compatible pollen grain germinates and forms a pollen tube. The tube grows through the style and reaches the ovule. Male gametes are delivered to the female gamete. Fertilisation forms a zygote. The zygote develops into an embryo and the ovule develops into a seed.

6 Marks Q22. Explain the male and female reproductive parts of a flower.

Answer: The stamen is the male part and consists of filament and anther. The anther produces pollen grains. The pistil/carpel is the female part and consists of stigma, style and ovary. The ovary contains ovules.

6 Marks Q23. Explain double fertilisation with equations.

Answer: Syngamy: Male gamete + egg → diploid zygote. Triple fusion: Male gamete + two polar nuclei → triploid primary endosperm nucleus. Together these processes are called double fertilisation and are characteristic of flowering plants.

6 Marks Q24. Explain self-pollination and cross-pollination and compare them.

Answer: Self-pollination occurs within the same flower or plant. Cross-pollination occurs between different plants of the same species. Cross-pollination generally promotes greater genetic mixing, whereas self-pollination tends to maintain greater genetic similarity.

6 Marks Q25. Explain the changes in flower parts after fertilisation.

Answer: The zygote develops into an embryo. The ovule becomes a seed and the ovary becomes a fruit. Other floral parts may wither and fall, although the exact fate of accessory floral parts can vary among plants.

6 Marks Q26. Explain why sexual reproduction leads to variation.

Answer: Sexual reproduction involves genetic material from two gametes. Their combination creates new genetic combinations. Therefore, offspring can differ from their parents and from one another, producing variation.

6 Marks Q27. Explain the importance of pollinating agents.

Answer: Pollinating agents such as wind, insects and animals transfer pollen from anther to stigma. This transfer enables pollen germination and subsequent fertilisation in flowering plants.

6 Marks Q28. Explain the complete sequence of sexual reproduction in flowering plants.

Answer: Flower formation → pollen production → pollination → pollen germination → pollen tube growth → male gamete delivery → fertilisation → zygote → embryo → seed → germination → new plant.

6 Marks Q29. Differentiate sexual and asexual reproduction.

Answer: Sexual reproduction involves gametes and fertilisation and produces greater genetic variation. Asexual reproduction generally involves one parent without gamete fusion and usually produces offspring genetically similar to the parent.

6 Marks Q30. Explain the role of sexual reproduction in adaptation and evolution.

Answer: Sexual reproduction produces genetic variation. Some variations may provide advantages under changing environmental conditions. Such advantageous variations can become more common over generations, contributing to adaptation and evolution.

23. CBSE Golden Points ⭐

⭐ Flower → reproductive structure of flowering plants.

⭐ Stamen → male reproductive part.

⭐ Anther → produces pollen grains.

⭐ Pistil/Carpel → female reproductive part.

⭐ Stigma → receives pollen.

⭐ Style → pathway for pollen tube.

⭐ Ovary → contains ovules.

⭐ Pollination → transfer of pollen from anther to stigma.

⭐ Fertilisation → fusion of male and female gametes.

⭐ Zygote → develops into embryo.

⭐ Ovule → Seed.

⭐ Ovary → Fruit.

⭐ Double fertilisation → Syngamy + Triple fusion.

⭐ Sexual reproduction → genetic variation.

24. One-Line Revision 🧠

🌸 Flower → Reproductive Organ

♂ Stamen → Male Part

🟡 Anther → Pollen

♀ Pistil → Female Part

🎯 Stigma → Receives Pollen

🌿 Style → Pollen Tube Path

🥚 Ovary → Ovules

🌬️ Pollination → Pollen Transfer

🔗 Fertilisation → Gamete Fusion

🌱 Ovule → Seed

🍎 Ovary → Fruit

🧬 Sexual Reproduction → Variation

25. Important Diagram Questions

1. Draw and label a typical flower.
2. Label anther and filament.
3. Label stigma, style and ovary.
4. Draw pollen tube growth through the style.
5. Explain pollination with a diagram.
6. Explain fertilisation in flowering plants.
7. Draw and explain double fertilisation.
8. Show conversion of ovule into seed and ovary into fruit.

26. Super-Fast Memory Trick 🚀

S → A → P → S → O → F → S

Stamen → Anther → Pollen → Stigma → Ovule → Fertilisation → Seed

O → F
Ovary → Fruit

O → S
Ovule → Seed

Syngamy + Triple Fusion = Double Fertilisation

27. Final Exam Revision

Complete Process:

Anther ↓ Pollen ↓ Pollination ↓ Stigma ↓ Pollen Tube ↓ Ovule ↓ Male Gamete + Female Gamete ↓ Zygote ↓ Embryo ↓ Seed ↓ Germination ↓ New Plant

Most Important Conversion:

Ovule → Seed     |     Ovary → Fruit

Most Important Competitive Point:

Double Fertilisation = Syngamy + Triple Fusion