Class 11 Chapter 3 Biology Important Questions and Answers

Biology is one subject that all of us should study to have a better understanding of the world we live in, and it is also the key subject for those that prepare for careers in the life sciences/healthcare domain. Chapter 3 of NCERT Class 11 Biology deals in detail with further classification within the Kingdom Plantae which is popularly known as the ‘Plant Kingdom’. 

It is noteworthy that as our understanding of the plant kingdom has changed over time, the same will result in a changed view of content as we knew it in the past. Fungi, as well as members of the Monera and Protista that have cell walls have now been excluded from Plantae, even though the earlier classifications placed them in the plant kingdom. Similarly, the cyanobacteria that were referred to as blue-green algae are not regarded as ‘algae’ anymore. This chapter describes Plantae under Algae, Bryophytes, Pteridophytes, Gymnosperms and Angiosperms and we will try to get a glimpse of a few Important Questions in Class 11 Biology Chapter 3 here. 

Extramarks is a leading educational company in India that provides numerous study materials related to the CBSE curriculum based on the NCERT books. Our experts have collated questions from different trusted sources in our question bank of Chapter 3 Class 11 Biology Important Questions. The Important Questions Class 11 Biology Chapter 3 contains all the vital questions from this chapter. Students must follow these questions and answers to improve their knowledge.

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CBSE Class 11 Biology Important Questions

Sr No. Chapters Chapters Name
1 Chapter 1 The Living World
2 Chapter 2 Biological Classification
3 Chapter 3 Plant Kingdom
4 Chapter 4 Animal Kingdom
5 Chapter 5 Morphology of Flowering Plants
6 Chapter 6 Anatomy of Flowering Plants
7 Chapter 7 Structural Organisation in Animals
8 Chapter 8 Cell the Unit of Life
9 Chapter 9 Biomolecules
10 Chapter 10 Cell Cycle and Cell Division
11 Chapter 11 Transport in Plants
12 Chapter 12 Mineral Nutrition
13 Chapter 13 Photosynthesis in Higher Plants
14 Chapter 14 Respiration in Plants
15 Chapter 15 Plant Growth and Development
16 Chapter 16 Digestion and Absorption
17 Chapter 17 Breathing and Exchange of Gases
18 Chapter 18 Body Fluids and Circulation
19 Chapter 19 Excretory Products and their Elimination
20 Chapter 20 Locomotion and Movement
21 Chapter 21 Neural Control and Coordination
22 Chapter 22 Chemical Coordination and Integration

Class 11 Biology Chapter 3 Important Questions

Solving questions from our question bank of Important Questions Class 11 Biology Chapter 3 helps students in increasing their knowledge related to this topic. Our team at Extramarks understands this crucial method of imparting education. Therefore, we focus on developing content that includes all the necessary questions and solutions related to the topics studied in the chapter. The solutions given in our question bank of Class 11 Biology Chapter 3 Important Questions cover the concepts of the chapter Plant Kingdom.

Given below are some of the important questions and solutions from our Important Questions Class 11 Biology Chapter 3.

Q1. What is the basis of the classification of Algae? 

Solution 1 –

Algae is a diverse group that contains aquatic and marine organisms ranging from autotrophic to eukaryotic. They are generally green due to the presence of Chlorophyll, but they can be found in various colours. They are classified in the presence of Chlorophyll, xanthophyll and phycoerythrin as Chlorophyceae, Phaeophyceae and Rhodophyceae, also called green, brown and red algae.

Generally, Algae are classified on criteria like-

  • Flagellations
  • Storage product
  • Cellular organisation
  • Constituent of cell wall

Q2. Describe the important characteristics of gymnosperms.

Solution 2-

  • The word gymnosperm means ‘naked seed’, meaning that the seeds are formed at the surface of their reproductive structure rather than enclosed within them as a fruit. The important characteristics of gymnosperm are: –
  •  The seeds are naked, i.e. the ovules are exposed before and after fertilisation.
  •  They are known as heterosporous as they produce two kinds of spores. 
  • Fertilisation can take place even when water is absent. 
  • The leaves are simple and compound, while the plant body is divided into roots, stems and leaves. 
  • The stem is branched as well as unbranched in nature. 

Q3. Both gymnosperm and angiosperms bear seeds, so why are they classified separately?

Solution 3 – 

The word gymnosperm means ‘naked seed’, which means that the seeds are formed at the surface of their reproductive structure rather than being enclosed within them as a fruit, while on the other hand, the seeds of Angiosperm are covered mostly by fruits. The lack of coverage in gymnosperms and the presence of the same in angiosperms lead to the difference in the process of dispersion and fertilisation.

That’s the main reason why they are classified differently.

Q4. Explain the following terms briefly with suitable examples – 

  1. Protonema d.Archegonium
  2. Antheridium e.Diplontic
  3. Sporophyll f.Isogamy

Solution 4 – 

  1. Protonema – It is the earliest phase in the life cycle of Moses. Also known as the first stage, it consists of creeping, green, branched filamentous structures. One of the major functions of these stages is the development of the gametophyte, a haploid cell.  
  2. Antheridium – It is the male sex organ in pteridophytes and bryophytes. It produces the male gametes, also called the sperm cell, through the sperm mother cells. 
  3. Sporophyll – It is a leaf-baring sporangium; these are found in pteridophytes. And its main function is to produce spores that further germinate to produce haploid gametophytes.
  4. Archegonium – It is known as the female sex organ in pteridophytes and bryophytes. It contains the female gamete, also called an egg, which fertilises it and forms a sporophyte.
  5. Diplontic – Diplontic is a term used in the life cycle of organisms where the diploid stage dominates, and the diploid number of chromosomes is formed in the somatic stage. The sporophyte formed in the diplontic stage is independent and photosynthetic.  
  6. Isogamy – isogamy is a type of sexual function where there is a fusion of similar gametes. This indicates that even though the gametes are morphologically similar, they still perform different functions. 

Q5. Write a note on the economic importance of algae and gymnosperm. 

Solution 5 – 

Economic Importance of Algae – 

Algae is a diverse group that contains aquatic and marine organisms ranging from autotrophic to eukaryotic. Green algae like Ulva and Chlorella are used for the process of photosynthesis through which food is generated. 

Algae like Caulerpa are used to form and obtain antibiotics.

The algae Chlamydomonas produce methane gas used in sewage oxidation tanks. 

Economic Importance of Gymnosperm- 

 The seeds of Pinus are roasted and eaten in nature. 

  1. The softwood of gymnosperms is also used in constructing furniture, plywood, packing cases, match sticks, railway sleepers etc.
  2.  The wood from Picea is used in the manufacture of paper.
  3.  Pine needles, a derivent of gymnosperm, are used to make fibre boards.
  4. A drug called Ephedrine is extracted from the plant Ephedra, which is classified under gymnosperm. This drug, Ephedrine, is useful for respiratory ailments such as asthma.

Q6. What is heterospory? Briefly comment on its significance. Give two examples.

Solution 6- 

Heterospory refers to the generation of two types of spores by a single plant. These spores are different in size and structure; one is called a Microspore, while the other is called a Megaspore. The microspore is smaller and gives rise to the male gamete after germination. 

On the other hand, Megaspores are larger and give rise to the female gamete after germination. The megaspore is enclosed within megasporangia, ensuring the zygote’s proper development. A zygote is formed after the process of fertilisation of the microgamete and the megagamete. Heterospory was first observed in plants like Selaginella and Salvinia. 

Q7. How would you distinguish monocots from dicots?

Solution 7 

Monocot plants contain a single cotyledon seed, while dicots contain two cotyledons. In monocots, their flowers are trimerous, the venation in leaves is parallel, and the vascular bundle is scattered. Also, in monocots, the primary root is short-lived and is replaced by the adventitious roots.

On the other hand, in dicots, their flowers are tetramerous or pentamerous; the leaves contain reticulate venation. The vascular bundle is organised in a ring structure. 

Q8. A plant shows Thallus’ level of organisation. It shows rhizoids and is haploid. It needs water to complete its life cycle and survives because the male gametes are motile. It may belong to

(a) Pteridophytes 

(b) Gymnosperms

(c) Monocots 

(d) Bryophytes

Solution 8- 

Option (d) is the correct Answer.


Bryophytes are the species of plants that show Thallus’ level of organisation. Aside from this, it is haploid and shows rhizoids. Also, bryophytes need water to complete their life cycle because the male gametes are motile. 

Q9. Give an example of the following plants with

  1. Haplontic life cycle
  2. Diplontic life cycle
  3. Haplo-diplontic life cycle

Solution 9 – 

  1. Haplontic life cycle – It is represented by a dominant haploid gametophyte. Examples of such life cycles are Volvox, Spirogyra and Chlamydomonas.
  2. Diplontic life cycle – It is represented by a dominant diploid stage or diploid sporophyte. Examples of the diplontic life cycle are Angiosperms, Gymnosperm and algae like Fucus.
  3. Haplo- diplontic life cycle – It involves the fusion of a haploid gametophyte and a diploid sporophyte. Examples of these are pteridophytes and bryophytes. 

Q10. The giant Redwood tree, also called Sequoia sempervirens, is a/an.

(a) Angiosperm

(b) Free fern

(c) Pteridophyte 

(d) Gymnosperm

Solution 10. Option (d) is the right option.

Explanation: Sequoia is the tallest tree that comes under the species gymnosperms. 

Q11. How are the male gametophytes and female gametophytes of pteridophytes and gymnosperms different? 

Solution 11- 

The male gametophytes in the pteridophytes are known as anthurium and are motile. At the same time, the female gametophyte of pteridophytes is not enclosed in the ovule.

While the female gametophyte in a gymnosperm is independent and enclosed in an ovule, the male gametophyte is non-motile, i.e. they are not flagellated in nature.

Q12. Comment on the lifestyle and nature of a fern and prothallus.

Solution 12- 

Fern:- Fern shows a diplo-haplontic life cycle where the diploid sporophyte represents the dominant and independent plant body which is also photosynthetic. The sporophyte in fern mainly produces spores that germinate to form free-living prothallus.

Prothallus:- The free-living prothallus represents a gametophyte. It is multicellular and photosynthetic. Prothallus needs a damp and shady place for their growth and development. It contains rhizoids, sex organs and food-laden parenchyma cells.

Q13. Plants of this group are diploid and well adapted to extreme heat and cold conditions. They also grow bearing sporophylls in compact structures called cones. The group in reference is

  1. Monocots
  2. Dicots
  3. Pteridophytes
  4. Gymnosperms

Solution 13- 

Option (d) is the right Answer.

Explanation – Gymnosperms have a dominant sporophyte and a reduced gametophyte. The male and female sex organs of the gymnosperm are formed to be cones or strobili. One of the main characteristics of gymnosperms is that their male and female gametes are separated from each other.  

Q14. The plant body of the higher plants is well-differentiated and well developed too. Roots are the organs that are used for the process of absorption of water. What is the part equivalent to roots in the less developed lower plants?

Solution 14- 

Although roots absorb water and exchange gases through diffusion, their equivalent in lesser developed plants is known as Rhizoids. Rhizoids are thread-like structures that can be unicellular or multicellular, depending upon the plant species. Rhizoids are unicellular in liverworts and multicellular in Moses. 

Q15. Each group of pants has some phylogenetic significance that concerns evolution: Cycas, one of the few living members under gymnosperms, is also called a ‘relic of the past. Can you generate a phylogenetic relationship of Cycas with any other group of plants that justifies the above statement?

Solution 15- 

Cycas come under gymnosperms and are one of the few living members; it is called the relic of the past because it is the connecting link between gymnosperm and pteridophytes. It shows similarities to flagellated antherozoids, megasporophylls that are leaf-like structures and the presence of female gametophyte-like archegonia. 

Q16. Lichen is usually classified as an example of a ‘symbiosis relation’ in plants where an algal and a fungal species live together for their mutual benefit. Which of the following will happen if algal and fungal partners are separated?

  1. Both will survive and grow normally and independent of each other.
  2. Both will die
  3. The algal component will survive, while the fungal component will die.
  4. The fungal component will survive while the algal partner will die. Based on your Answer, how do you justify this association as symbiosis

Solution 16- Option (b) is the right Answer.

Explanation: Lichen is a species of plant that forms a symbiotic relationship with algae and fungi. Both algae and fungi depend on each other for food and protection; hence, both are necessary for survival. The algae synthesise food while the fungi part protects it, so if one of them is separated, both die. 

Q17. Heterospory, i.e., the formation of two types of spores – microspores and megaspores is a characteristic feature in the life cycle of a few pteridophytes and all spermatophytes. Do you think heterospory has some evolutionary significance in the plant kingdom?

Solution 17- 

One major evolutionary significance in the plant kingdom is the generation of in situ embryo development, where the embryo derives nutrition from the female gametophyte and is provided with better protection. 

Heterospory has also led to the evolution of the seed habit, which helped the plant grow and flourish over time. 

Q18. Why are bryophytes also called the amphibians of the plant kingdom?

Solution 18-

Bryophytes are species that can survive on both land and water. They are called amphibians of the plant kingdom because they can’t complete their life cycle without water; water is necessary for their fertilisation process. 

Water also plays an important role in the dehiscence of antheridium and archegonium. Also, a small amount of water is required for the survival of the bryophytes. 

Q19. If the diploid number of chromosomes of a flowering plant is 36 chromosomes. What would be the chromosome number in the endosperm of the flowering plant? 

  1. 36
  2. 18
  3. 54
  4. 72

Solution 19 – Option (c ) is the right Answer.

Explanation – As the flowering plant is diploid, so the number of chromosomes is 36, but in a haploid, it will be 2n = 36,

               n= 18 

And we know the number of chromosomes in the endosperm is 3n so it will be 3×18 = 54. 

Q20. Protonema is

(a) Haploid and is found in mosses

(b) Diploid and is found in liverworts

(c) Diploid and is found in pteridophytes

(d) Haploid and is found in pteridophytes

Solution 20- Option (a ) is the right Answer.

Explanation: Protonema is the juvenile stage in Moses’s life cycle, which is haploid. Most of them resemble multicellular green algae in nature. 

Q21. The respective male and female reproductive organs of several pteridophytes and gymnosperms are comparable to the floral structures of the angiosperms. Compare the various reproductive parts of pteridophytes and gymnosperms’ reproductive structures of angiosperms.

Solution 21 – 

The following reproductive part that is compared with the angiosperms are- 

  1. Storbili/ cone – Flower
  2. Microsporophyll – Stamen
  3. Megasporophylls – Pistil/ Carpel
  4. Microsporangium – Another
  5. Megasporangium – Ovule

Q22. What do you mean by double fertilisation and triple fusion?

Solution 22- 

Double fertilisation is the fertilisation of two male gametes with their respective female gametes. In it, one male gamete fertilises with the female gamete egg and forms a diploid zygote. At the same time, the other male gamete fuses with the two polar nuclei found in the ovule to form a triploid zygote that further develops into an endosperm.

And when the three haploid gametes fuse to form an endosperm, this process is termed triple fusion. 

Q23. Discuss the phylogenetic relationship of Cycas with any other group of plants.

Solution 23- 

Cycas are a plant that resembles a palm-like structure. It exhibits a phylogenetic relationship with pteridophytes and contains some evolutionary characteristics like- 

Slow growth and development, generating monocyclic wood, shedding seed when the embryo is immature and little secondary growth.

Aside from this, it possesses circinate ptyxis and contains a well-defined archegonium.

Q24. Distinguish between Antheridia and Archegonia.

Solution 24 – 

Antheridia is the male reproductive organ that produces numerous male gametes. The male gametes are generally motile, i.e., flagellated. Antheridia resembles a racket-shaped structure. And there is an absence of sterile cells inside antheridia. 

On the other hand, Archegonia is the female reproductive part that generates one female gamete at a time. The female gametes are non-motile, i.e., non, flagellated. The Archegonia resembles a flask shape structure. And there is the presence of sterile cells, which are developed from the Neck canal cells and Venter canal cells. 

Q25. When the fruit ripens, what are the changes that take place?

Solution 25 – 

Three main changes take place when the fruit ripens. These changes are –

  1. The starch gets converted into sugar
  2. Breakdown of Chlorophyll takes place, resulting in the fruit’s colour change.
  3. There is a difference in taste, texture, and flavour due to the production of various organic substances.

Q26. Explain the alternation of generation in bryophytes briefly.

Solution 26- 

Bryophytes are non-vascular plants that require water for fertilisation. They show an alternation of generation between the independent gametophyte generation and the dependent sporophyte generation. The gametophyte stage is responsible for the production of sex organs like sperm and egg, while the sporophyte stage is responsible for the production of spores. So a developing relationship between the sporophytic and gametophytic stages is said to be the alternation of generation.

For example, Moss is a gametophytic plant. But the development of it is started by the spores. The spore grows and forms into a Protonema which is the juvenile stage. It further generates the male and female gametes. And the process of fertilisation takes place. This alternation of the gametophyte stage with the sporophyte stage is the alternation of generation.

Q27.What are angiosperms? Give their characteristic features.

Solution 27 – 

The characteristics features of Angiosperms are- 

  1. The ovules are well protected and enclosed within the ovary; after fertilisation, the ovules develop into seeds.
  2. The male gamete, i.e., the pollen grain, is generated at a huge amount to ensure fertilisation.
  3. During pollination, in the male gametes, pollen grain falls on the stigma and enters the ovary through Onicrophy. 
  4. The pollen grain is a three-cell structure when dehisced. 
  5. The embryo sac is an eight-cell structure that becomes seven after fertilisation.
  6. Both double fertilisation and triple fusion occur in the Angiosperms, where one male gamete fuses with the egg nucleus to form a zygote, and another male gamete fuses with the secondary nucleus to form a triploid endosperm. And when the three haploid gametes fuse to form an endosperm, this process is termed triple fusion. 

Q28. What are the different lifestyles shown by Angiosperms?

Solution 28- 

There are four major lifestyles shown by the Angiosperms that are Hydrophytic, Halophytes, Xerophytes and Insectivorous. These are described briefly – 

  1. Hydrophytic plants – These are the plants that live in water or marshy areas. They are further classified as submerged and free-floating plants. Examples of submerged plants are Hydrilla and Vallisneria. At the same time, Examples of free-floating plants are Pistia and Nymphea.
  2. Halophytes plants – They are classified as xerophytic plants but under marine conditions. These plants cannot survive in fresh or aquatic water. 
  3. Xerophytes plants – These plants survive under the scarcity of water. Example cactus. They don’t need water for their growth and development.
  4. Insectivorous plants – A few Angiosperms plants trap insects to overcome the shortage of nitrogen. They need it for photosynthesis, and these plants depend on insects for their food. Some examples of these types of plants are the Pitcher plant, sundew etc.

Q29. Define a fruit.

Solution 29 – fruit is the developed part of the ovary that contains seeds and matures after the fusion of the male and female gametes. The endosperm formed after fertilisation ensures the growth of the fruit by providing it with nourishment. 

Q30. What features have led to the success and dominance of vascular plants? 

Solution 30 – 

Vascular plants have features like – 

A cutin layer helps to reduce transpiration as it is waterproof.

Mechanical tissue that provides support and strength.

Deep penetrating roots absorb water and minerals for the proper growth and development of plants.

The presence of a well-developed vascular system.

Q31. Give five distinguishing characteristics of red algae.

Solution 31 – 

The distinguishing characteristics of red algae are:-

  1. The motile stage in red algae is absent in their life cycle
  2. They mostly grow in salty water and are found in marine ecosystems. 
  3. Their cell wall is made of cellulose and hydrocolloids.
  4. They contain photosynthetic pigments like Chlorophyll and carotenoids for the process of photosynthesis.
  5. They are further classified into two main types: unicellular filamentous and parenchymatous forms.

Q32. How do red algae differ from brown algae? 

Solution 32 – 

Red algae are unicellular and contain Floridian starch as a reserve food material. Aside from phycocyanin and phycobilins, it contains Chlorophyll, a pigment for the process of photosynthesis.

On the other hand, brown algae are filamentous, containing Laminarin starch as their reserve food material. It contains both Chlorophyll a and chlorophyll b pigment for the process of photosynthesis.

Examples of red algae are Polysiphonia and Gelidium. Examples of brown algae are Laminaria and Fucus.

Q33. Apart from Chlorophyll, algae have several other pigments in their chloroplast. What pigments are found in blue-green, red and brown algae responsible for their characteristic colours?

Solution 33. Aside from Chlorophyll, algae contain xanthophyll, fucoxanthin and r-phycoerythrin, which impart distinctive colours. Algae under Chlorophyceae impart green colour, commonly known as green algae. Phaeophyceae contain fucoxanthin as a major pigment which imparts brown colour. Similarly, Rhodophyceae imparts red colour with the help of r-phycoerythrin pigment. 

Q34. How do fungi differ from Algae?

Solution 34 – 

Fungi are saprophytic organisms that are dependent on other species for their food. Hence they are also called parasites. They absorb nutrients and organic salts and hence lack the chlorophyll pigment: yeast and albugo. 

On the other hand, algae contain Chlorophyll, so they are photosynthetic in nature. They show autotrophic nutrition and absorb inorganic salts and nutrients. Examples – Chlamydomonas and Ulothrix. 

Q35. What is the difference between the process of syngamy and triple fusion?

Solution 35 – 

Syngamy is the fusion of male and female gametes, i.e. the fusion of sperm and egg to form a zygote. In contrast, triple fusion is the fusion of the other male gamete to the diploid secondary nucleus to form the primary endosperm nucleus. 

Q36. How would you differentiate between monocots and dicots?

Solution 36 – 

Monocots contain adventitious roots, parallel leaves, trimerous floral parts, endospermic seeds and one cotyledon. While on the other hand, dicots contain tap roots, leaves that contain reticulate venation, tetramerous or pentamerous floral parts and non-endospermic seeds. Dicots also contain two cotyledons. 

Q37. Describe the common mode of reproduction in Angiosperms.

Solution 37 – 

The common mode of reproduction in Angiosperm involves Stamen and Pistil. The Stamen is the male reproductive part that consists of a slender filament with anthers at the tip, which generates pollen grains. At the same time, Pistil is the female reproductive part comprising stigma, style and ovary. Stigma is the upper portion where pollen grains attach themselves, style is the long tube-like structure through which pollen grain travels and the ovary contains the female gamete, which is enclosed in the ovule, and here fertilisation takes place. Double fertilisation and triple fusion is the common mode of reproduction. 

Q38. Describe the main features of pteridophytes.

Solution 38 – 

Pteridophytes mainly occur in tropical and humid climates; they are small-sized and are divided into roots, stems, and leaves. They are a vascular plant that produces neither flower nor seeds, so their main function is the dispersion of spores. They are multicellular and independent. Examples of such plants are ferns, horsetails, clubmoss etc. Pteridophytes are the first group of plants that developed vascular tissue containing the Xylem and phloem. The xylem is responsible for the transportation of water, while the phloem is responsible for the transportation of food and nutrients. The Xylem is unidirectional, i.e. from root to leaves, while the phloem is bidirectional, i.e. from leaves to roots and vice versa. 

Q39. Give some important features of dicots.

Solution 39 – The dicots are a part of angiosperms. Angiosperms are flowering plants with special structures responsible for producing pollen grains and ovules. These flowering plants are divided into two classes Monocots and Dicots. 

Dicots or dicotyledons are characterised by woody habitat, reticulate venation, tap roots and usually the presence of two or more cotyledons. They also contain scattered vascular bundles and flower patterns that are tetramerous or pentamerous. Also, they contain non-endospermic seeds. 

Q 40. Name the plants with

  • Diplontic life cycle
  • Haplontic life cycle
  • Haplo-diplontic life cycle

Solution 40. The answer for the above question is as follows

  • Diplontic life cycle- All seed-bearing plants
  • Haplontic life cycle- Volvox
  • Haplodiplontic life cycle- Bryophytes

Q 41. Which organisms are called Amphibians of the plant kingdom because these plants can live in soil but are dependent on water for sexual reproduction.

Solution 41. Bryophytes are called Amphibians of the plant kingdom because these plants can live in soil but are dependent on water for sexual reproduction.

Q 42. Name the plants which produce seeds but no flowers or seeds?

Solution 42. Pteridophytes produce spores but no flowers or seeds.

Q 43. What are two classes of Bryophytes?

Solution 43. Mosses and Liverworts are two classes of Bryophytes.

Q 44. Where are red algae found?

Solution 44. The Red algae are found in coral reefs.

Q 45. What is the use of air vesicles in brown algae?

Solution 45. The air vesicles in brown algae help maintain buoyancy.

Q 46. Which algae are found in the deepest waters?

Solution 46. The red algae are found in the deepest waters.

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Q.1 Identify the class of plant kingdom on the basis of given characteristic features.
1. They fix half of the CO2.
2. They increase the amount of oxygen in their surroundings.
3. 70% of their marine forms are edible.


Algae are CO2 fixers. They are oxygen producers. Most of their marine forms are edible in nature.

Q.2 Following types of life cycle are found in various plants. Choose the correct organism, in which it is found.
i. Haplo-diplontic
ii. Diplontic
iii. Haplontic


i- Polysiphonia, ii- Fucus, iii- Ulothrix

Polysiphonia is an alga which exhibits Haplo-diplontic life cycle. The alga Fucus exhibits diplontic life cycle. The alga Ulothrix exhibits haplontic life cycle.

Q.3 The fresh water filamentous green alga with a characteristic spiral, ribbon-shaped chloroplast is


Spirogyra is a genus of filamentous green algae of the order Zygnematales, named for the helical or spiral arrangement of the chloroplasts that is diagnostic of the genus. It is commonly found in freshwater areas, and there are more than 400 species of Spirogyra in the world.

Q.4 Which of the following agents helps male gamete to reach the female gamete for fertilisation in ferns?


In ferns, each and rocyte forms a motile sperm which requires water to reach the archegonium. Sexual fertilisation is of oogamous type.

Q.5 Identify the labelled part in the given image and its importance.


The given image is showing the female gametophyte of Marchantia. In this image, ?X? is the gemma cup. In liverworts, gemma cups are located on the thalli. They produce gemmae which are green, multicellular, asexual buds.

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FAQs (Frequently Asked Questions)

1. Are the Important Questions for CBSE Class 11 Biology Chapter 3 - the Plant Kingdom reliable?

Yes, these important questions and answers are prepared by the subject matter experts of Extramarks and hence are very exhaustive and good. One can use these study resources while preparing for exams and at the time of their revision.


2. How to score good marks in Science?

Here are a few things that a student must do to obtain and great score in science 

  • Study regularly and thoroughly.
  • Be aware of the syllabus fully. Be thorough with the NCERT textbooks and the exemplar – as most of the questions are based on these.
  • Study from the Extramarks website as we have exhaustive content that is easy to understand and recall language and totally covers the syllabus. If one studies our content and reads it a couple of times, all fundamental concepts will get cleared plus the student will learn how he should respond to these questions.
  • Students should also go through the list of books that are best suited for the CBSE curriculum. The list of books is provided on our Extramarks website. 

Thus, following the above-mentioned guidelines, a student can rest assured that s/he will do well in exams.