NCERT Class 11 Biology Chapter 3 Notes Plant Kingdom- Download PDF Notes

Download PDF of Plant Kingdom Class 11 Notes

This chapter explains how plants are grouped into categories, like algae, bryophytes, pteridophytes, gymnosperms, and angiosperms. Students can download the PDF of NCERT Class 11 Biology Chapter 3 Notes. Reading everything from the textbook can be time-consuming, so having NCERT Notes for Class 11 Biology improves the learning.

Download PDF

Also Read:

• NCERT solutions for Class 11 Biology Chapter 3 Plant Kingdom

Class 11 Biology Chapter 3 Plant Kingdom Notes

Here, students will get a simple, clear explanation of each group of plants, from algae to angiosperms. The Plant Kingdom Class 11 Notes are prepared by subject experts following the NCERT curriculum, which helps students revise quickly. They can understand the complex topics easily and be ready to solve any kind of questions based on this chapter.

Introduction to the Plant Kingdom

The Plant kingdom covers all green plants, including algae, bryophytes, pteridophytes, gymnosperms, and angiosperms. Earlier classification placed fungi, bacteria, and cyanobacteria under plants, but now these are separated. Classification has evolved from simple characters (e.g., shape, colour) to modern phylogenetic systems using molecular, cytological, and chemical data.

Algae

• Simple, thalloid, chlorophyll-bearing, mostly aquatic organisms.
• Found in freshwater, marine water, moist soil, and even on animals.
• Reproduce vegetatively (fragmentation), asexually (zoospores), and sexually (isogamy, anisogamy, oogamy).
• Important because they fix CO₂, produce oxygen, and are primary producers in aquatic food chains.
• Economic uses: food (Porphyra, Laminaria), hydrocolloids (algin, carrageenan), agar (microbiology and food industry), Chlorella as a protein supplement.
• Examples of algae (Volvox, Spirogyra, Fucus)

Classes of Algae

The different classes of algae have been discussed below:

Chlorophyceae (Green Algae):

• Grass-green due to chlorophyll a & b
• Food is stored as starch in pyrenoids
• Cell wall of cellulose + pectin
• E.g., Chlamydomonas, Volvox, Spirogyra

Phaeophyceae (Brown Algae):

• Olive-green to brown due to fucoxanthin
• Stored food: laminarin or mannitol
• Cell wall with cellulose + algin
• Usually marine, large-sized (kelps)
• E.g., Laminaria, Fucus

Rhodophyceae (Red Algae):

• Red pigment r-phycoerythrin
• Store food as flouridean starch
• Mostly marine
• E.g., Polysiphonia, Porphyra, Gelidium, corallina

Bryophytes

• The bryophytes are called “amphibians of the plant kingdom” as they live on land but need water to reproduce
• Occur in moist, shaded areas
• Main plant body: gametophyte (haploid), produces gametes
• Sporophyte is attached to and dependent on the gametophyte
• E.g., liverwort, hornwort, mosses

Liverworts

• Thalloid, dorsiventral structure
• Asexual reproduction by fragmentation or gemmae in gemma cups
• E.g., Marchantia

Mosses

• The gametophyte has two stages: protonema (creeping) and leafy stage
• Reproduce vegetatively by fragmentation
• E.g., Funaria, Polytrichum

Pteridophytes

• First land plants with vascular tissues (xylem + phloem)
• True root, stem, and leaves present
• The dominant plant body is the sporophyte
• Reproduce via spores; the gametophyte is independent but small
• Show heterospory in genera like Selaginella, leading to seed habit evolution
• E.g., Selaginella, Equisetum

Gymnosperms

• Seeds are “naked” (no fruit covering)
• Ovules exposed before and after fertilisation
• Usually large trees or shrubs (e.g., Pinus, Cycas, Sequoia)
• Well-adapted leaves, tap roots, and cones
• Heterosporous, with separate male and female cones
• Male gametophyte = pollen grain
• The female gametophyte develops inside the ovule
• E.g., Pinus, Ginkgo

Angiosperms

• Most advanced plants, with flowers
• Ovules are enclosed in ovaries, forming fruits after fertilisation
• The largest group in the plant kingdom
• Provide food, medicine, timber, etc.
• Classified as dicots (two cotyledons) and monocots (one cotyledon)
• E.g., Wheat, Mustard, Rice

Characteristics of the Plant Kingdom

The plants make their food through photosynthesis, have cell walls made of cellulose, and store food in the form of starch. They are necessary for maintaining oxygen levels and forming the foundation of food chains. The following points show the important features of the Plant Kingdom:

• Plants are made up of many specialised cells that form tissues and organs.
• They make their food using sunlight with the help of chlorophyll (types a and b).
• Their cells have walls made of cellulose, providing rigidity and protection.
• Chlorophyll a and b help absorb light efficiently for photosynthesis.

Reproductive Features of the Plant Kingdom

Types of reproduction include sexual reproduction and asexual reproduction, depending on the group. Alternation of generations is a common pattern in their life cycles. It includes two distinct multicellular phases:

• Produces haploid gametes (egg and sperm)
• Forms sporophytes after fertilisation of gametes diploid), produces spores through meiosis

This alternation maintains genetic diversity and provides the continuation of the plant life cycle.

Physiological Features of the Plant Kingdom

Plants perform essential physiological processes that maintain growth, development, and their relationship with the environment. These include:

• Photosynthesis is important for getting energy for the metabolic activities of plants and for the synthesis of oxygen used in aerobic respiration by living beings.
• Through cellular respiration, plant cells can split glucose molecules and release free energy for use in other cellular processes. This process, called cellular respiration, takes place in the mitochondria, where oxygen is used in the process and carbon dioxide and water are formed as waste.
• Plants use stomata to release water vapour by transpiration, regulating temperature and promoting nutrient flow for growth.

Also, Read

• NCERT Notes for Class 11 Physics
• NCERT Notes for Class 11 Chemistry
• NCERT Notes for Class 11 Mathematics

Plant Kingdom Previous Year Questions and Answers

Some of the questions that have come in past years from the chapter are given below. Students preparing for exams can also practice from the Plant Kingdom Class 11 Notes for better clarity.

Question 1. The giant Redwood tree (Sequoia sempervirens) is a/an

Option 1. Gymnosperm

Option 2. Free fern

Option 3. Pteridophyte

Option 4. Angiosperm

Answer :

Redwood trees are a Gymnosperm that have earned many labels; known as the tallest tree, oldest tree, largest by trunk volume, etc. They belong to the Cupressaceae family and include species like the Coast Redwood and Giant Sequoia. Their towering height and immense lifespan make them iconic symbols of resilience and natural beauty.

Hence, the correct answer is option (1) Gymnosperm.

Question 2. If the diploid number of a flowering plant is 36. What would be the chromosome number in its endosperm?

Option 1. 36

Option 2. 54

Option 3. 18

Option 4. 72

Answer :

Endosperm is formed through the fusion of a haploid male gamete and a diploid secondary nucleus. Consequently, the endosperm has a triploid nucleus, which will have three times the number of chromosomes as in a haploid nucleus.

Hence, the correct answer is option (2) 54.

Question 3. 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

Option 1. Monocots

Option 2. Gymnosperms

Option 3. Pteridophytes

Option 4. Dicots

Answer :

Cones are a primary feature of gymnosperms. Furthermore, gymnosperms are admirably adapted to extreme conditions. The plants that produce seeds are called gymnosperms, although they don't have fruits like angiosperms do. These plants generate a cone-like structure at the terminal of stalks or on the surface of scales or leaves.

Hence, the correct answer is option (2) Gymnosperms.

Also Read:

• NCERT Solution
• NCERT Solutions for Class 11
• NCERT Solutions for Class 11 Biology

How to Use Plant Kingdom Class 11 Notes Effectively?

Understanding the plant kingdom requires a clear revision strategy because of the detailed classification and examples involved.

1. Start by revising the classification levels step by step, moving from algae to angiosperms, so that concepts remain clear.

2. Use Class 11 Biology Chapter 3 Plant Kingdom Notes to focus on key differences between different groups, as they are frequently asked in exams.

3. Practice diagrams of life cycles (such as bryophytes and pteridophytes) regularly to improve visual learning.

4. While solving previous year questions, use the Class 11 Biology Chapter 3 Plant Kingdom Notes nearby to check the terms and definitions.

5. Revise botanical terms and examples and practice questions to test both concept clarity and memory.

Chapter-Wise NCERT Class 11 Notes Biology

Given below are the notes of each chapter, which provide a clear and concise summary of each chapter, making it easier for students to revise important concepts for exams.