CBSE Class 11 Biology Exemplar NCERT Solutions: Chapter 3 - Plant Kingdom

Reviewed by · Updated on

NCERT Solutions PDF Class 11 PDF

This resource provides detailed NCERT Solutions for CBSE Class 11 Biology Exemplar, Chapter 3: Plant Kingdom. It covers essential topics such as the classification of organisms, the characteristics of different plant groups like algae, bryophytes, pteridophytes, gymnosperms, and angiosperms, and their reproductive strategies. The solutions explain concepts like gamete fusion, plant body organization, and the structure of reproductive parts. These solutions are designed to help students grasp complex biological concepts, understand the evolutionary progression in the plant kingdom, and prepare effectively for their board examinations by offering clear explanations and step-by-step problem-solving approaches.

Home

Quick info

BoardCBSE
ClassClass 11
SubjectBiology Exemplar
Session2026
LanguageEnglish
TypeNCERT Solutions
ChapterChapter 3

Chapter summary

Chapter 3 of the CBSE Class 11 Biology Exemplar, focusing on the Plant Kingdom, is explained through these NCERT Solutions. The solutions cover the classification of major plant groups, including algae, bryophytes, pteridophytes, gymnosperms, and angiosperms. Key concepts such as thallus organization, gamete fusion (isogamy, anisogamy, oogamy), the structure of plant bodies (holdfast, stipe, frond), and reproductive adaptations are detailed. The solutions aim to clarify the distinct characteristics and life cycles of these plant groups.

Learning outcomes

  • Understand the classification of major plant groups.
  • Identify the characteristics of algae, bryophytes, pteridophytes, gymnosperms, and angiosperms.
  • Explain different types of gamete fusion (isogamy, anisogamy, oogamy).
  • Describe the plant body organization in different plant groups.
  • Recognize the role of water in the reproduction of bryophytes.
  • Differentiate between sporophyte and gametophyte generations.
  • Understand the structure of the embryo sac in angiosperms.

Topics covered

Paper topics

  • Classification of Plants
  • Algae
  • Bryophytes
  • Pteridophytes
  • Gymnosperms
  • Angiosperms
  • Gametophyte
  • Sporophyte
  • Gamate Fusion
  • Plant Body Organization
  • Embryo Sac Structure
  • Cyanobacteria

Important topics

  • Classification of Plant Groups
  • Reproductive Strategies (Gamate Fusion)
  • Bryophytes and Pteridophytes Life Cycles
  • Gymnosperms Characteristics
  • Angiosperm Embryo Sac Structure
  • Plant Body Differentiation

PDF preview

Read page by page below. PDF is streamed from the official NCERT website — no download button on this page.

Loading document …
Page of
Loading page …

Questions and Solutions

Multiple Choice Questions (MCQs) - Question 1

Q. 1 Cyanobacteria are classified under:
  1. Protista
  2. Plantae
  3. Monera
  4. Algae
Solution: Cyanobacteria, also commonly known as blue-green algae, are primitive prokaryotic organisms. Based on their cellular structure and genetic makeup, they are exclusively classified under the Kingdom Monera. This kingdom encompasses all forms of bacteria, which are characterized by the absence of a well-defined nucleus and other membrane-bound organelles. The other options, Protista, Plantae, and Algae (often considered within Protista or Plantae depending on the classification system), include eukaryotic organisms that are either unicellular or multicellular.

Answer: (c) Monera

Multiple Choice Questions (MCQs) - Question 2

Q. 2 Fusion of two motile gametes which are dissimilar in size is termed as:
  1. oogamy
  2. isogamy
  3. anisogamy
  4. zoogamy
Solution: Sexual reproduction in various plant groups, particularly in algae, shows diverse modes of gamete fusion. When two motile gametes fuse, and these gametes are not similar in size and structure, the process is called anisogamy. For example, certain species of Chlamydomonas exhibit anisogamy. Oogamy is a specific type of sexual reproduction where a large, non-motile female gamete (egg) fuses with a smaller, motile male gamete (sperm). Isogamy refers to the fusion of two gametes that are similar in size, shape, and structure. Zoogamy is a general term related to sexual reproduction in animals.

Answer: (c) anisogamy

Multiple Choice Questions (MCQs) - Question 3

Q. 3 Holdfast, stipe and frond constitutes the plant body in case of:
  1. Rhodophyceae
  2. Chlorophyceae
  3. Phaeophyceae
  4. All of these
Solution: In the members of the class Phaeophyceae, commonly known as brown algae, the plant body exhibits a significant degree of differentiation. It is typically anchored to the substratum by a structure called the holdfast. A stalk-like structure, known as the stipe, connects the holdfast to the main photosynthetic part of the plant body, which is called the frond. This complex organization is characteristic of Phaeophyceae and distinguishes them from simpler algal forms.

Answer: (c) Phaeophyceae

Multiple Choice Questions (MCQs) - Question 4

Q. 4 A plant shows thallus level of organisation. It shows rhizoids and is haploid. It needs water to complete its life cycle because the male gametes are motile. Identify the group to which it belongs to:
  1. pteridophytes
  2. bryophytes
Solution: The description points to the characteristics of Bryophytes. Bryophytes are plants that exhibit a thallus level of organization, meaning their plant body is not differentiated into true roots, stems, and leaves. They are typically haploid and possess rhizoids for anchorage. A crucial feature of their life cycle is the dependence on water for reproduction, as the male gametes (antherozoids) are motile and require a thin film of water to swim from the antheridium to the archegonium for fertilization. Pteridophytes, while having a gametophyte stage, show a higher level of organization and adaptations for terrestrial life.

Answer: (d) bryophytes

Multiple Choice Questions (MCQs) - Question 5

Q. 5 A prothallus is:
  1. a structure in pteridophytes formed before the thallus develops
  2. a sporophytic free living structure formed in pteridophytes
  3. a gametophyte free living structure formed in pteridophytes
  4. a primitive structure formed after fertilisation in pteridophytes
Solution: In the life cycle of pteridophytes (ferns and their allies), the haploid spore germinates to form a gametophyte generation. This gametophyte is typically a small, inconspicuous, free-living, and photosynthetic structure called a prothallus. It is usually heart-shaped and bears the sex organs, namely the antheridia (producing male gametes) and archegonia (producing female gametes). Therefore, a prothallus is a gametophytic structure formed after spore germination and before the development of the sporophyte generation.

Answer: (c) a gametophyte free living structure formed in pteridophytes

Multiple Choice Questions (MCQs) - Question 6

Q. 6 Plants of this group are diploid and well adapted to extreme conditions. They grow bearing sporophylls in compact structures called cones. The group in reference is:
  1. monocots
  2. dicots
  3. pteridophytes
  4. gymnosperms
Solution: Gymnosperms represent a group of plants that are well-adapted to diverse and often extreme environmental conditions. These plants are typically diploid and exhibit a dominant sporophyte generation. A key characteristic is the presence of sporophylls, which are modified leaves that bear sporangia. These sporophylls are often aggregated into compact structures called cones or strobili. Examples include cycads and conifers. Monocots and dicots are categories within angiosperms, which have seeds enclosed within a fruit, unlike gymnosperms where seeds are naked. Pteridophytes have vascular tissues but do not typically form cones in the same manner as gymnosperms and their seeds are not naked.

Answer: (d) gymnosperms

Multiple Choice Questions (MCQs) - Question 7

Q. 7 The embryo sac of an angiosperm is made up of:
  1. 8 cells
  2. 7 cells and 8 nuclei
  3. 8 nuclei
  4. 7 cells and 7 nuclei
Solution: The embryo sac in angiosperms is the female gametophyte. It develops within the ovule and is typically an oval-shaped structure. A mature embryo sac contains a total of eight nuclei organized into specific cellular units. At the micropylar end, there are two synergids and one egg cell, collectively forming the egg apparatus. At the chalazal end, there are three antipodal cells. In the center of the embryo sac lies a large central cell containing two polar nuclei. Therefore, the embryo sac consists of seven cells (two synergids, one egg cell, three antipodal cells, and the central cell) and eight nuclei (one nucleus in each synergid, egg cell, and antipodal cell, and two nuclei in the central cell).

Answer: (b) 7 cells and 8 nuclei

Common mistakes

  • Confusing the classification of cyanobacteria.
  • Misidentifying types of gamete fusion.
  • Incorrectly associating plant body structures with specific groups.
  • Confusing the characteristics of pteridophytes and gymnosperms.
  • Errors in understanding the ploidy level of different plant stages.

Revision tips

  • Focus on the key distinguishing features of each plant group (algae, bryophytes, pteridophytes, gymnosperms, angiosperms).
  • Pay close attention to the reproductive methods and terminology used (e.g., isogamy, anisogamy, oogamy).
  • Review the diagrams and descriptions of plant body structures like holdfast, stipe, and frond.
  • Understand the life cycle differences, particularly the role of water and the nature of gametophytes and sporophytes.
  • Use the MCQs to test your understanding of classification and key characteristics.

Practice MCQs

Q1. Cyanobacteria, also known as blue-green algae, are primitive prokaryotes and are classified under which kingdom?

Q2. The fusion of two motile gametes that are dissimilar in size is specifically termed as:

Q3. In which group of algae does the plant body, consisting of a holdfast, stipe, and frond, represent a significant level of organization?

Q4. A plant exhibiting a thallus level of organization, with rhizoids and haploid nature, requiring water for motile male gamete transfer, belongs to which group?

Q5. What is a prothallus in the life cycle of pteridophytes?

Q6. Which plant group is diploid, well-adapted to extreme conditions, and bears sporophylls in compact structures called cones?

Q7. The embryo sac of an angiosperm, which functions as the female gametophyte, typically consists of:

Frequently asked questions

What is the main focus of the NCERT Solutions for Class 11 Biology Exemplar, Chapter 3?

These solutions focus on the Plant Kingdom, covering its classification, the characteristics of different plant groups like algae, bryophytes, pteridophytes, gymnosperms, and angiosperms, and their reproductive methods.

How do these solutions help in understanding plant reproduction?

The solutions explain various modes of sexual reproduction, including different types of gamete fusion (isogamy, anisogamy, oogamy), and the role of water in fertilization for certain groups like bryophytes.

What is the significance of the 'Plant Kingdom' chapter for Class 11 Biology?

This chapter is crucial for understanding the diversity of plant life, their evolutionary progression, and the fundamental biological processes that sustain them, forming a basis for higher studies in botany.

Are the questions in the solutions exactly the same as in the NCERT Exemplar?

Yes, the questions are preserved exactly as they appear in the NCERT Exemplar, including their numbering and problem statement. The wording has been expanded for clarity where needed.

How are the solutions presented for each question?

Each solution is rewritten to be more comprehensive, providing clear steps, reasoning, and explanations to help students understand the concepts thoroughly, rather than just providing a brief answer.

What kind of plant body organization is discussed in these solutions?

The solutions discuss different levels of plant body organization, from the thallus level in bryophytes to the more differentiated structures like holdfast, stipe, and frond found in Phaeophyceae (brown algae).

Important links

Content reviewed by the NCERT Help team. Editorial Team and update policy

NCERT Solutions PDF PDF on NCERT Help. URL unchanged for search indexing.