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NCERT Solutions for Class 12 Biology Chapter 1 Sexual Reproduction In Flowering Plants

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Class 12 Biology Chapter 1 Questions and Answers - FREE PDF Download

Embark your journey with Vedantu through class 12 Biology chapter 1 exercise solutions provided by Vedantu. This gives access to Sexual Reproduction in Flowering Plants NCERT PDF, elucidating fundamental principles crucial for understanding the subject's intricacies and topics such as fertilisation, polyembryony, apomixis, etc.

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By accessing the class 12 chapter 1 questions and answers PDF, students gain comprehensive insights into the core concepts outlined in the curriculum. With a focus on clarity and depth, these resources serve as indispensable tools for students navigating through Sexual Reproduction in Flowering Plants Class 12 PDF. Check out the Revised class 12 Biology syllabus and start with Vedantu to embark on a journey of academic excellence.


Glance on NCERT Solutions for Class 12 Biology Chapter 1 | Vedantu

  • Master the fundamentals and a basic understanding of sexual reproduction with class 12 biology chapter 1 exercise solutions.

  • Concise explanations for all the questions in the 12th biology 1st chapter exercise and a free PDF packed with clear concepts are provided.

  • The NCERT Solutions for Class 12 Biology Chapter 1, Sexual Reproduction In Flowering Plants, assists students in familiarising themselves with the process of reproduction in flowers. 

  • This chapter explains how flowering plants portray the sexual reproduction method and lead to pollen and ova production. 

  • The chapter further explains the pre-fertilization process of the flower's sexual reproduction.

  • In this chapter, students can learn about the process involved in forming male and female gametes and their role in producing a new plant. 

  • Topics such as pollination, pre-fertilization events, post-fertilization events, and fusion of male and female gametes are some of the important concepts that are explained in a detailed manner in this chapter.

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Access NCERT Solutions for Class 12 Biology Chapter 1- Sexual Reproduction in Flowering Plants

1. Name the parts of an angiosperm flower in which the development of male and female gametophytes takes place.

Ans: In pollen sacs of the anther, male gametophytes (microgametogenesis) develop up to the 2-celled stage. The nucellus of an ovule is where the gametophyte develops (megagametogenesis).


2. Differentiate between microsporogenesis and megasporogenesis. Which type of cell division occurs during these events? Name the structures formed at the end of these two events?

Ans: Microsporogenesis and megasporogenesis differ in the following ways:


Microsporogenesis

Megasporogenesis

The process by which microspore mother cells divide and produce pollen grains is known as microsporogenesis.


Megasporogenesis is the process by which megaspore mother cells are formed and differentiate into megaspores by meiosis.

Located within the pollen sac of the anthers.

It is present in the nucellus of the ovule.

A pollen grain produced by a microspore mother cell functions properly.

The megaspores have only one functional megaspore.

Results in the formation of pollen grains (male  gametophyte)

 

Resulting in the formation of embryo sacs (female gametophyte)

Microspore mother cells and megaspore mother cells are every diploid, as they have two sets of chromosomes.

The mother cells for megaspores and microspores enlarge and undergo meiosis in order to produce four haplotypic cells called megaspores and microspores, respectively.



Meiotic cell Division occurs during microsporogenesis and megasporogenesis. It leads to the production of haploid gametes, also known as reductional division.


3. Arrange the following terms in the correct developmental sequence: Pollen grain, sporogenous tissue, microspore tetrad, pollen mother cell, male gametes.

Ans: The sporogenous tissue is composed of a pollen mother cell, a microspore tetrad, pollen grains, and male gametes.


4. With a neat, labeled diagram, describe the parts of a typical angiosperm ovule.

Ans:


Structure of Angiosperm Ovule


An angiosperm ovary is capable of forming a small structure called an ovule. Nucellus, a multi-layered cellular tissue, develops as the ovule first appears on the placenta. Placentas are attached to ovules via a stalk known as a funicle. A funicle attaches to a placenta at the hilum. The hypodermal cells of the nucellus enlarge and transform into megaspore mother cells. One haploid cell undergoes meiosis to form an embryo sac (female gametophyte). The others do not develop. A pollen tube enters an ovule through a small opening called a micropyle, surrounded by one or two protective layers. Ovules consist of the nucellus and integuments of a fully developed embryo.


5. What is meant by monosporic development of female gametophytes?

Ans: The female gametophyte or embryo sac develops only from one of the four megaspores in many flowering plants. Degeneration occurs in the three remaining megaspores. The monosporic type of embryo sac formation is referred to as the monosporic type of embryo development.


6. A neat diagram explains the 7-celled, 8-nucleate nature of the female gametophyte.


Structure of Female Gametophyte


Ans: 

  • Two nuclei form after the first mitotic division and move towards the micropylar and chalazal end, respectively.

  • Division and redivision occurs to form 8-nucleate stage and consequently there are four nuclei, each on either end.

  • A typical female gametophyte or embryo sac is formed after the 8-nucleate stage. The antipodal and micropylar end of each of the eight nuclei comprises the six nuclei grouped. Two synergids and an egg cell are at the centre of the egg apparatus. 

  • The polar nuclei are located within the large central cell of the embryo sac just below the egg apparatus. A typical female gametophyte comprises seven cells with eight nuclei, as both polar nuclei are present within the same cell.


7. What are chasmogamous flowers? Can cross-pollination occur in cleistogamous flowers? Give reasons for your answer.

Ans: The anther and stigma of chasmogamous flowers are exposed for pollination. Cleistogamous flowers are incapable of cross-pollination. Therefore, only self-pollination is caused by these closed flowers. During the dehiscence process of cleistogamous flowers, anthers dehisce into closed flowers. As a result, pollen grains are exposed to stigma. Therefore, it is impossible for cross-pollination to occur, such as Oxalis and Viola.


8. Mention two strategies evolved to prevent self-pollination in flowers

Ans: An individual race's vigor and vitality are diminished by continuous self-pollination. In order to prevent self-pollination and to promote cross-pollination, flowering plants have developed many devices. Cross-pollination is most frequently ensured by dichogamy and self-sterility.

Dichogamy: Different maturation times for the anthers and stigmas prevent self-pollination.

Self-sterility (or self-incompatibility): pollen grains from some flowers do not germinate on their stigma due to the presence of self-sterility genes. Examples include tobacco and potatoes.


9. What is self-incompatibility? Why does self-pollination not lead to seed formation in self-incompatible species?

Ans: On its stigma, a flower that does not produce pollen grains is incompatible or self-sterile. This condition is called self-incompatibility or self-sterility. It is called pollination when pollen grains are transferred from the stigma to the anthers. As a result of this transference, seeds are formed. The process of self-pollination occurs when pollen grains are shed from the anther in the same flower to the stigma in the same flower. Some flowers, however, do not produce seeds when self-pollination occurs because they contain the same sterile gene on the pistil and pollen grain. Since pollen grains cannot germinate, male gametes cannot fertilize egg cells. This prevents the ovule from developing into a seed.


10. What is a bagging technique? How is it useful in a plant breeding program?

  • Ans: When applied to emasculated flowers (which are in the bud stage), a bag of polythene butter paper prevents pollen contamination of its stigmas. Emasculated flowers can be removed from their buds and stuffed into a butter paper bag before anthesis. 

  • A pre-sterilized brush is used to dust the stigmas of mature emasculated flowers with pollen grains of desired male plants. Flowers are then re-bagged until the fruits are formed. 

  • Artificial hybridisation uses this technique primarily. Plant breeders use this technique to prevent unwanted pollen grains from contaminating the stigma of flowers.


11. What is triple fusion? Where and how does it take place? Name the nuclei involved in triple fusion.

Ans: Triple fusion is a process by which male gamete fuses with two polar nuclei within the embryo sac of Flowering Plants. The events taking place in triple fusion are:


  • The pollen grain germinates by getting dusted on the stigma and giving rise to a pollen tube that enters the ovule.

  • The pollen tube passes into one of the synergids and releases two male gametes one of which fuses with the egg nucleus and forms a zygote.

  • The other gamete fuses with the two polar nuclei located in the central cell and forms a triploid endosperm nucleus.


12. Why do you think the zygote is dormant for some time in a fertilized ovule?

Ans: Zygotes become embryos after resting for a while. Until some amount of endosperm forms, most zygotes remain dormant. Developing embryos need this nutrition to grow and develop properly.


13. Differentiate between:

(a) Hypocotyl and epicotyl;

(b) Coleoptile and coleorhiza;

(c) Integument and testa;

(d) Perisperm and pericarp.

Ans:

(a) Hypocotyl and Epicotyl;

Epicotyl

Hypocotyl

This is the part of the embryonal axis between plumule and cotyledon nodes.

The area between the cotyledonary node and radicle forms part of the embryonal axis.

When epicotyl 2 elongates during hypogeal germination, the soil retains the cotyledons.

Hypocotyls extend so that cotyledons emerge from the soil during epigeal germination.

Epicotyls have plumules at their terminal ends.

Hypocotyls have radicals at their terminal ends.


(b) Coleoptile and Coleorhiza;

  Coleoptile 

Coleorhiza

A foliar structure called the coleoptile surrounds the epicotyl and a leaf primordium.

Roots and their caps are enclosed in a sheath called a coleorhiza.

It protects the plumule during emergence from soil.

For the first leaf to appear, there is an opening at the end of the coleoptile. The coleorhiza is a solid structure.

 

Plumules are protected from the soil when they emerge from soil.

Radicles are not protected when they pass through the soil.

It grows much beyond the grain

After emergence from grain, it stops growing

Coleoptile after emergence from soil

Coleorhiza does not come out of the soil.

Germination occurs when the seed becomes green and begins to photosynthesize.

It remains nongreen

 


 (c) Integument and Testa;

Integument

Testa

The ovule is covered by this membrane.

In other words, it is the outer covering of a seed.

There are two or three layers, and it is thin.

It is layered and quite thick.

Live cells make up its structure.

Cells in it are no longer alive.

There are no sclereids.

Sclereids are found in abundance in cells.

The ovule produces it at the chalazal end.

The ovule outer integument is the source of the ovule structure.

The integument is pre fertilised.

Structures that develop postfertilization are called testa


(d) Perisperm and Pericarp.

Perisperm

Pericarp

It serves as the nucleus of the seed.

From the ovary wall develops a covering for the fruit.

Seeds contain it.

It is a component of fruit.

Usually, it is dry.

There is no moisture or flesh in it.

Many times, seeds do not function properly.

Protection and nutrition are also provided by this covering.

Seeds without perisperm are rare.

Every fruit contains this.


14. Why is an apple called a false fruit? Which part(s) of the flower forms the fruit?

Ans: True fruit is an ovary that has ripened botanically. Often called false fruits, these are fruits in which the thalamus, floral parts, and ovary are present. Apple is derived from the thalamus and is hence called a false fruit.  Mainly the fleshy thalamus of apples can be eaten—the ovaries from a parthenocarpic fruit after or without fertilisation.


15. What is meant by emasculation? When and why does a plant breeder employ this technique?

Ans: The stem of a flower bud is systematically excised to remove the anthers and stamens before they die. In order to minimize self-pollination, this is done. Hybridization by artificial means includes emasculation. This method is used by plant breeders to prevent the pollination of adjacent flowers and pollinate stigmas with pollen of the desired variety.


16. If one can induce parthenocarpy through the application of growth substances, which fruits would you select to induce parthenocarpy and why?

Ans: The fruit of the parthenocarpy is seedless. The ovary does not fertilize them before they develop. A few seedless fruits are of great economic importance, such as banana, grape, orange, pineapple, guava, watermelon, and lemon. In fruits with edible seeds or seeds (e.g., pomegranates), parthenocarpy is not selected.


17. Explain the role of tapetum in the formation of pollen-grain walls.

Ans: Microsporangia are surrounded by a thin layer called the tapetum. Multinucleated and polyploidy tapetal cells make up the tissue. Pollen grains develop as a result of them. Ubisch bodies are found in these cells and contribute to the ornamentation of the microspores and pollen grains. Sporopollenin is a substance produced by the Ubisch bodies of the tapetal cells. This substance is present on the exine layer of pollen grains. A spiny appearance is attributed to the exine of pollen grains due to the presence of this compound.


18. What is apomixis and what is its importance?

Ans: The asexual reproduction process of apomixis results in seeds without fertilization, such as in certain species of Asteraceae and Grasses. The hybrid seed industry relies on this method. Increasing productivity is the leading reason for cultivating hybrids. However, the main problem is the need to grow hybrid seeds annually since seeds from hybrid plants do not preserve hybrid characteristics for long periods because of the segregation of characters. By introducing apomixis into hybrid seeds, this can be avoided. As a result, scientists are seeking genes associated with apomixis.


Topics Covered in Biology Class 12 Chapter 1 Sexual Reproduction In Flowering Plants

List of Topics Covered in Class 12 Biology Chapter 1

Topics

Subtopics

Flower

Structure, Morphology

Pre- Fertilization: Structure and Events

Stamen, Microsporangium, Pollen Grain, Pistil, Megasporangium, Embryo-sac

Double Fertilization

Events

Post Fertilization

Endosperm, Embryo, Seed

Apomixis and Polyembryony



Key Features of NCERT Biology Class 12 Chapter 1 Sexual Reproduction in Flowering Plants Solutions 

Sexual Reproduction In Flowering Plants, Class 12, NCERT Solutions is a compilation of effective resources for studying the chapter effectively. Here are some of the benefits of the chapter.


  • The students can download the reproduction in flowering plants class 12 NCERT PDF on their laptops or computers and can even get them printed for studying without internet connectivity.

  • Subject experts have explained the different concepts covered in this chapter in an easily understandable manner for the convenience of students.

  • All types of textbook questions and exercises are solved and explained in the NCERT Solutions PDF.

  • The NCERT Solutions have been developed as per the prescribed CBSE Term 1 syllabus.

  • The solutions provided come with simple and well-structured explanations to aid easy understanding.

  • Labeled diagrams have been supplemented with explanations to facilitate easy grasping of the concepts.

  • The solutions have been designed to enhance the students’ conceptual knowledge of sexual reproduction in flower plants.

  • The biology experts have taken proper care in curating the solutions while considering the latest CBSE Class 12 protocols.

  • These NCERT Solutions of Biology will also be very helpful and effective for NEET aspirants and other entrance exams.


Explore Study Materials for Chapter 1 - Sexual Reproduction in Flowering Plants


Conclusion

NCERT Solutions for Chapter 1, Sexual Reproduction in Flowering Plants, forms the foundation for understanding Plant Reproduction. Biology Class 12 Chapter 1 weightage can vary depending on the exam boards, but students can expect 4-6 questions from this Chapter. Students can access Sexual Reproduction in Flowering Plants Class 12 PDF that helps clear their doubts from the 12th biology 1st chapter exercise.


NCERT Solutions for Class 12 Biology | Other Chapter-wise Links

Given below are the other chapter-wise links for NCERT Solutions for Class 12 Biology for all other chapters.



Other Related Links for Class 12 Biology

FAQs on NCERT Solutions for Class 12 Biology Chapter 1 Sexual Reproduction In Flowering Plants

1. What is the correct stepwise method to solve NCERT questions on sexual reproduction in flowering plants according to the CBSE 2025–26 syllabus?

Start by reading the NCERT exercise question carefully, then identify the specific biological process or structure being asked about. Write concise, sequential answers, use CBSE-recommended terminology, support explanations with labeled diagrams if required, and connect each step to the process described in the textbook. Always conclude with a summary aligning with the syllabus keywords.

2. How should students approach diagram-based questions in Class 12 Biology Chapter 1 while using NCERT Solutions?

For diagram-based questions, students should draw neat, well-labeled diagrams, such as the structure of female gametophyte or parts of an angiosperm ovule. Indicate key parts using arrows or pointers, and accompany each diagram with a brief stepwise annotation to help visualise the related biological concepts clearly, as explained in NCERT Solutions for Class 12 Biology.

3. What is the recommended method to answer ‘differentiate between’ type questions in NCERT Solutions for Class 12 Biology?

Use a table or clear point-wise format to contrast the features, beginning with the main basis of comparison. Example: to differentiate microsporogenesis and megasporogenesis, list the location, process, types of cell division, and resulting structures, highlighting each aspect for clear understanding. This approach matches the expected CBSE answer format.

4. Why is it essential to use step-by-step NCERT Solutions for mastering application-based questions in sexual reproduction in flowering plants?

Step-by-step solutions ensure that students address every part of a complex process, such as double fertilisation or mechanisms of self-incompatibility. This method helps avoid missing key details and strengthens conceptual clarity, which is critical for application-based questions in CBSE board and NEET entrance examinations.

5. How do NCERT Solutions help clarify common misconceptions in Chapter 1 Sexual Reproduction in Flowering Plants?

They address frequent errors, such as confusing self-incompatibility with self-pollination or misunderstanding the role of the tapetum. Each step in the solution provides scientific logic with supporting points, which helps to correct such misconceptions and reinforces accurate learning.

6. What role does the bagging technique play in artificial hybridisation as per CBSE 2025–26 NCERT Solutions?

The bagging technique prevents unwanted pollen from fertilising emasculated flowers. Emasculated flowers are covered until the desired pollen is applied, ensuring cross-pollination with selected traits. This method is standard for controlled hybridisation in plant breeding, as detailed in NCERT Solutions.

7. Can you explain, in sequence, how double fertilisation takes place in angiosperms based on NCERT Class 12 Solutions?

  • Pollen tube delivers two male gametes into the embryo sac.
  • One gamete fuses with the egg cell to form a diploid zygote (syngamy).
  • The other gamete fuses with two polar nuclei to form a triploid endosperm (triple fusion).
  • This process is unique to angiosperms and termed double fertilisation.

8. What strategies do NCERT Solutions suggest for students to verify their self-written answers in Biology Chapter 1?

After attempting an answer, compare your steps with those provided in the NCERT Solutions. Check for CBSE-specific keywords, correct scientific terms, and whether your diagrams are accurate and appropriately labeled. Refining your answers with this comparison improves precision and exam readiness.

9. Why is mastering NCERT Solutions critical for scoring well in both CBSE board exams and medical entrance tests?

The solutions provide syllabus-aligned explanations and clarify all exercise and in-text questions extensively. Accurate step-wise answers help students understand not only concepts but also exam paper presentation, increasing their chances of full marks and ease in tackling competitive exams like NEET.

10. In what way do NCERT Solutions for Class 12 Biology Chapter 1 help students prepare for concept-linked, higher-order thinking questions (HOTS)?

The stepwise approach builds a robust foundation of core concepts, making it easier to apply knowledge to HOTS questions. Solutions often incorporate insight into underlying principles, such as genetic diversity resulting from sexual reproduction, fostering logical reasoning vital for advanced problems.

11. How does following the method in NCERT Solutions minimise mistakes in CBSE Biology board answers?

Strict adherence to the method ensures that answers are well-structured, each scientific term is used properly, and all steps are logically ordered. This maximises scoring potential and helps avoid common pitfalls like incomplete explanations or unlabeled diagrams.

12. What are the advantages of using labeled diagrams in NCERT Solutions for topics like the embryo sac and ovule structure?

Labeled diagrams make complex structures clearer, enable better recall during exams, and meet CBSE marking criteria, where schematic labeling is often specifically rewarded. Diagrams in the solutions act as visual aids to complement stepwise textual explanations.

13. How can students apply the CBSE answer writing technique modelled in NCERT Solutions to other chapters in Biology?

By consistently using a stepwise, point-wise, and diagram-supported approach across topics, students can enhance their overall biology paper performance. This method ensures clarity, completeness, and exam-focused responses throughout the syllabus.

14. How do NCERT Solutions ensure clarity between similar terms like apomixis and parthenocarpy in Sexual Reproduction in Flowering Plants?

Solutions define each term distinctly and provide examples, explaining that apomixis is asexual seed formation without fertilisation, which preserves hybrid traits, while parthenocarpy results in fruit development without seeds. Stepwise distinctions clarify potential points of confusion for students.

15. What should students do if they are unable to solve a particular exercise question in NCERT Class 12 Biology Chapter 1?

First, review the related textbook section and try to break down the question step by step. If difficulty persists, consult the detailed, syllabus-aligned NCERT Solution for that question to understand the stepwise problem-solving method and ensure future self-attempts are improved by learning from the approach provided.