NCERT Solutions for Class 11 Biology Chapter 3 - Plant Kingdom

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Understanding Chapter 3 becomes easier when students have access to clear and simple solutions. Having the Class 11 Biology Chapter 3 - Plant Kingdom question answer helps in quick revision and better concept clarity. To make learning smooth and flexible, students can use the NCERT Solutions for Class 11 Biology.

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• NCERT Notes for Class 11 Biology Plant Kingdom

• NCERT Exemplar Solutions for Class 11 Biology Plant Kingdom

Access the Class 11 Biology Chapter 3 - Plant Kingdom Solutions

The detailed answers to the Plant Kingdom chapter are provided below. These are prepared by the Biology experts to make your learning easy. Students can understand the concepts by doing regular practice with the Class 11 Biology Chapter 3 - Plant Kingdom question answer.

Question 1. What is the basis of the classification of algae?

Answer:

Algae are chlorophyll-containing thallus-bearing plants characterised by the absence of the embryo stage. A variety of algae are found in a variety of habitats. The various types of algae are classified based on their pigments, flagellation, and the reserve food material. Based on these criteria, algae are of three types, i.e,. red algae, brown algae, and green algae.

Question 2. When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm, and an angiosperm?

Answer:

In the life cycle of a liverwort, reduction division takes place in the capsule for the formation of haploid spores that will grow into a gametophytic thallus after germination. In mosses, the gametes fertilise and a zygote is formed. The zygote develops into the sporophyte. In the capsule of the sporophyte, reduction division takes place, and haploid spores are formed, which, on germination, give rise to a gametophytic thallus. In ferns, meiosis takes place in the sporangia present on leaves for the production of spores. Gymnosperms, which have sporophytic plant bodies, show reduction division in their microsporangia and megasporangia for the formation of microspores and megaspores. In the case of angiosperms, the main plant body is diploid, and meiosis occurs for the formation of gametes. Therefore, in the life cycle of an angiosperm, meiosis takes place in the anther and ovary at the time of microspore and megaspore formation, respectively.

Question 3. Name the three groups of plants that bear archegonia. Briefly describe the life cycle of any one of them.

Answer:

Three groups of plants that have archegonia are given below:

• Bryophytes

• Pteridophytes

• Gymnosperms.

The life cycle of a pteridophyte then consists of two morphologically distinct phases:

(i) The gametophytic phase

(ii) The sporophytic phase.

These two phases come one after another in the life cycle of a pteridophyte, and this phenomenon is called alternation of generations. The gametophyte is a haploid with a single set of chromosomes. It produces male sex organs, antheridia, and female sex organs, archegonia.

(i) The antheridia may be embedded or projecting types. Each antheridium has a single-layered sterile jacket enclosing a mass of astrocytes.

(ii) The astrocytes are flask-shaped, sessile, or shortly stalked and differentiated into globular venters and tubular necks.

(iii) The diploid zygote is the first cell of the sporophytic generation. It is retained inside the archegonium and forms the embryo.

(iv) The antherozoids, after liberation from the antheridium, reach up to the archegonium, fuse with the egg, and form a diploid structure known as a zygote.

(v) The archegonium contains a large egg, which is non-motile.

Question 4. Mention the ploidy of the following: protonemal cell of a moss; primary endosperm nucleus in a dicot; leaf cell of a moss; prothallus cell of a fern; gemma cell in Marchantia; meristem cell of a monocot; ovum of a liverwort; and zygote of a fern.

Answer:

Question 5. Write a note on the economic importance of algae and gymnosperms.

Answer:

Economic importance of algae

1. Green algae such as Ulva, Caulerpa, Enteromorpha, Chlorella, etc., are used as food rich in lipids, protein, vitamins, minerals, etc.

2. Chlorella and Caulerpa are also used to obtain antibiotics.

3. Several green algae, such as Chlamydomonas, Chlorella, Scenedesmus, etc, are used in sewage oxidation tanks.

Economic importance of Gymnosperms

1. The seeds of Pinus gerardiana are roasted and eaten.

2. The softwood of gymnosperms is used in the construction of furniture, plywood, packing cases, matchsticks, railway sleepers, etc.

3. The wood from Picea, Pinus, Larix, and Abies is used in the manufacture of paper.

4. Pine needles are used to make fibre boards.

5. Resins containing terpenes, resin acids, and esters can be obtained from gymnosperms. Resins are used in waterproofing, sealing joints, etc.

6. A drug called ephedrine is extracted from Ephedra, which is a gymnosperm. This drug is useful in respiratory ailments such as asthma.

Question 6. Both gymnosperms and angiosperms bear seeds, so why are they classified separately?

Answer:

Both gymnosperms and angiosperms come under the group Spermatophyta or seed-bearing plants. However, angiosperms and gymnosperms are classified separately in spermatophyta because gymnosperms possess naked seeds, i.e., their seeds are not enclosed in the ovary, whereas angiosperms possess seeds that are enclosed in the ovary.

Question 7. What is heterospory? Briefly comment on its significance. Give two examples.

Answer:

Heterospory- It refers to the existence of two types of meiospores, i.e., microspores and megaspores, in a single plant. These microspores and megaspores are formed respectively within microsporangia and megasporangia, which in turn are borne on two distinct sporophylls called microsporophylls and megasporophylls, respectively. The microspores and megaspores, upon germination, give rise to male and female gametophytes, respectively. The megaspore is retained in megasporangia, and it ensures proper development of the zygote. This is formed after the fusion of microgametes with the megagametes. The zygote is retained on the plant, and it is considered to be a precursor of the seed habit.

Significance of heterospory- Heterospory is considered to be an important step in evolution as it is a precursor of the seed habit, which is seen in higher plants. Heterospory was first observed in the pteridophyte Selaginella and Salvinia.

Question 8. Explain briefly the following terms with suitable examples:-

(1) protonema

Answer:

Protonema- It refers to the creeping, green, branched, often filamentous structure that is formed directly after the germination of a moss spore. It represents the first stage in the life cycle of moss. Protonema is short-lived, and it grows prostrate on the surface. Protonema bears rhizoids for the absorption of materials.

Question 8. Explain briefly the following terms with suitable examples

(2) antheridium

Answer:

Antheridium- It is the male sex organ found in bryophytes, pteridophytes, and some algae. It is surrounded by a sterile jacket of cells.

Question 8. Explain briefly the following terms with suitable examples

(3) archegonium

Answer:

Archegonium- It is a female sex organ found in bryophytes, pteridophytes, and gymnosperms. Based on the presence of an archegonium, these three groups are referred to as archegoniate. It generally possesses a swollen ventral and a tubular neck. The venter possesses ventral canal cells and the neck contains neck canal cells. Archegonium also contains the female gamete, which is called the egg.

Question 8. Explain briefly the following terms with suitable examples

(4) diplontic

Answer:

Diplontic- This type of life cycle is found in gymnosperms and angiosperms. In such plants, the main plant body is diploid and represented by the sporophyte. The sporophyte bears sex organs that produce haploid gametes through meiosis. The gametophyte is highly reduced and completely dependent on the sporophyte for nourishment. After fertilisation, the diploid zygote develops into a new sporophyte.

Question 8. Explain briefly the following terms with suitable examples

(5) sporophyll

Answer:

Sporophylls- These refer to leaf-like appendages bearing sporangia in pteridophytes, gymnosperms, etc. Sporophylls can be either microsporophylls or megasporophylls, and respectively they can form either microsporangia or megasporangia.

Question 8. Explain briefly the following terms with suitable examples

(6) isogamy

Answer:

Isogamy- It refers to the process of fertilisation of two gametes that are exactly similar to each other in morphology, physiology, anatomy, etc. Such gametes are called isogametes.

Question 9. Differentiate between the following:-

(i) red algae and brown algae

Answer:

Differences between red algae and brown algae are as follows:

Question 9. Differentiate between the following:- (ii) liverworts and moss

Answer:

Differences between liverworts and mosses are as follows

Question 9. Differentiate between the following:- (iii) homosporous and heterosporous pteridophyte

Answer:

Question 10. Match the following (column I with column II)

Answer:

Correct matching is (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)

Question 11. Describe the important characteristics of gymnosperms.

Answer:

Important characteristics of gymnosperms

1. Gymnosperms are seed plants in which the seeds remain exposed on the surface of megasporophylls.

2. Gymnosperms are represented by 900 living species.

3. Gymnosperms are perennial and woody plants (either trees or bushes). The xylem of gymnosperms does not possess vessels except in Gnetum. Phloem is without companion cells and sieve tubes.

4. Two types of sporophylls occur in gymnosperms. These are microsporophylls and megasporophylls. The microsporophylls aggregate to form male strobili or cones, while the megasporophylls aggregate to form female strobili or cones. Microsporangia and megasporangia are borne on microsporophylls and megasporophylls, respectively.

4. Microsporangia give rise to microspores or pollen grains, whereas megasporangia form megaspores. The male and female gametophytes are formed within micropores and megaspores.

5. The female gametophyte contains archegonia. The male gametophyte produces only two male gametes or sperm.

6. The pollination is direct and is accomplished by wind, i.e., anemophily. A pollen tube is formed in gymnosperms. It is called siphonogamy.

7. Seeds contain endosperm.

NCERT Solutions for Class 11 - Subject-wise

• NCERT Solutions for Class 11 Maths

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Important Question of Class 11 Biology Chapter 3 Solutions

Given below is an important question along with a well-detailed explanation from this chapter. Doing regular practice with the questions helps students to get familiar with the question pattern. For more such questions, students can refer to the NCERT Solutions for Class 11 Biology Chapter 3 - Plant Kingdom.

Question: Which chlorophyll is found only in the photosynthetic members of the Chromista as well as the dinoflagellates?

A. Chlorophyll a

B. Chlorophyll b

C. Chlorophyll c

D. Chlorophyll d

Answer: The correct answer is option (C), Chlorophyll c

Explanation: Only the photosynthetic members of the Chromista, which include dinoflagellates and creatures like brown algae, diatoms, and other related families, contain chlorophyll c. These organisms use chlorophyll c (along with other pigments like chlorophyll a) to absorb light energy and have a special type of photosynthesis.

Also, check the NCERT Books and NCERT Syllabus here :

• NCERT Books Class 11 Biology

• NCERT Syllabus Class 11 Biology

• NCERT Books Class 11

• NCERT Syllabus Class 11

Approach to Solve Plant Kingdom Class 11 Question Answer

Students can follow the steps given below to answer the questions effectively. This chapter includes a lot of memorisation and understanding of concepts.

1. Students should understand the classification of the plant kingdom by going through the textbook thoroughly. Focus should be given on major groups like Algae, Bryophytes, Pteridophytes, Gymnosperms, and Angiosperms.

2. Prepare the short notes of the features, along with examples of each plant group. Students can take help from the Class 11 Biology Chapter 3 - Plant Kingdom question answer to prepare notes.

3. Students are advised to take the help of tables for easy comparison between the different groups.

4. Practice well-labelled diagrams wherever required, as diagram-based questions are common in exams. Students can refer to the Class 11 Biology Chapter 3 - Plant Kingdom Solutions for easy understanding.

5. Solve previous years' question papers, and practice with NCERT Solutions Class 11 to get familiar with the question pattern. This also increases confidence in answering the questions effectively.

What Students Learn from Plant Kingdom NCERT Solutions

The Plant Kingdom chapter introduces students to the diversity of plant life. It explains how plants are systematically classified into different groups based on features.

1. Students learn about the general characteristics and examples of lower plants like algae, which play an important role in the ecosystem.

2. Through Plant Kingdom NCERT Solutions, learners gain the knowledge of the features of pteridophytes, gymnosperms, and angiosperms with simple explanations

3. They can understand the life cycle and alternation of generations in bryophytes and how they act as a link between algae and higher plants.

4. The Plant Kingdom class 11 question answer also covers the economic importance of plants and their role in everyday life.

What Extra Should Students Study Beyond the NCERT for NEET?

Along with NCERT, students can refer to a few extra topics and resources to prepare better for NEET. A table is provided below for some of the extra concepts. Along with this, students should also practice the diagrams and flow charts, which are included in the NCERT Solutions for Class 11 Biology Chapter 3 - Plant Kingdom.

NCERT Chapter-wise Solutions for Class 11 Biology

NCERT solutions for all the class 11 biology chapters are given below:-