URMILA SCIENCE ACADEMY
BY- B.K. SAMOTYA SIR
Important questions & answers
Class 11th Biology
Class 11 Biology – Chapter 3: Plant Kingdom
A. Objective Type Questions (30)
Q1. Funaria belongs to which group? Explain in detail.
Answer: Funaria is a moss, belonging to Bryophyta.
Bryophytes are non-vascular plants, small, green and usually found in moist places. They show alternation of generations: gametophyte dominant and sporophyte dependent. Funaria gametophyte consists of rhizoids, leafy shoots, while sporophyte has foot, seta, capsule. Example: Funaria hygrometrica.
Q2. Stored food in Rhodophyceae is:
Answer: Red algae store Floridean starch. They have pigments chlorophyll a, d and phycoerythrin giving red colour. Mostly marine; used for agar, carrageenan, food, and fertilizers.
Q3. Brown algae contain which pigment?
Answer: Brown algae contain Fucoxanthin along with chlorophyll a and c. Stored food: mannitol and laminarin. Includes kelps like Macrocystis, mostly marine.
Q4. Which plant group is called “Amphibians of Plant Kingdom”?
Answer: Bryophytes, because they live on land but need water for sexual reproduction. Male gametes are motile, require water to reach egg.
Q5. Sporophyte dominant in which group?
Answer: Pteridophytes, Gymnosperms, Angiosperms. Sporophyte is independent and photosynthetic.
Q6. Protonema stage is found in:
Answer: Mosses like Funaria and Polytrichum. It is the first filamentous stage of gametophyte.
Q7. First terrestrial plants were:
Answer: Bryophytes, as they evolved from aquatic algae.
Q8. Xylem without vessels is found in:
Answer: Pteridophytes and Gymnosperms, called tracheids.
Q9. Male sex organ of algae is called:
Answer: Antheridium, produces motile male gametes (sperm).
Q10. Zygote divides by meiosis in:
Answer: Algae, producing haploid spores.
Q11. Which algae is called “Kelps”?
Answer: Brown algae (Macrocystis), large marine forms.
Q12. Agar is obtained from:
Answer: Red algae (Gelidium, Gracilaria).
Q13. Vascular tissue first appeared in:
Answer: Pteridophytes, xylem and phloem present.
Q14. Gymnosperms are also called:
Answer: Naked seeded plants, as seeds are not enclosed in fruit.
Q15. Smallest angiospermic plant:
Answer: Wolffia, floating tiny plant.
Q16. Double fertilization is a feature of:
Answer: Angiosperms, forming zygote and triploid endosperm.
Q17. Siphonogamy is found in:
Answer: Gymnosperms and Angiosperms, fertilization via pollen tube.
Q18. Embryo sac is:
Answer: Female gametophyte of Angiosperms, develops within ovule.
Q19. Chlorophyll a and c are found in:
Answer: Brown algae (Phaeophyceae).
Q20. Algae used as space food:
Answer: Chlorella, rich in protein and vitamins.
Q21. Male gametes of bryophytes are called:
Answer: Antherozoids, motile with flagella.
Q22. Largest algae:
Answer: Macrocystis, brown algae reaching 60–100 meters.
Q23. Homosporous pteridophytes produce:
Answer: Single type of spores → produce bisexual gametophyte.
Q24. Heterosporous pteridophytes produce:
Answer: Two types of spores: microspores (male) and megaspores (female).
Q25. Gymnosperms evolved in which era?
Answer: Mesozoic Era, dominant in Jurassic period.
Q26. First vascular land plants:
Answer: Pteridophytes, like ferns.
Q27. Stored food of brown algae:
Answer: Mannitol and Laminarin.
Q28. Non-motile gametes are found in:
Answer: Red algae, unlike green algae.
Q29. Archegonium is female organ of:
Answer: Bryophytes and Pteridophytes, multicellular, protects egg.
Q30. Thallus of algae is
Answer: Simple, autotrophic, may be unicellular, filamentous, colonial, or multicellular.
B. Fill in the Blanks (30)
Q31. Bryophytes are dependent on _____ for fertilization.
Answer: Water (motile sperm need water to reach egg).
Q32. Angiosperm endosperm is formed after _____ fertilization.
Answer: Double.
Q33. Liverworts belong to division _____.
Answer: Bryophyta.
Q34. Male gamete of gymnosperms is carried by _____.
Answer: Pollen tube.
Q35. Stored food in red algae is _____.
Answer: Floridean starch.
Q36. Smallest flowering plant is _____.
Answer: Wolffia.
Q37. Largest algae is _____.
Answer: Macrocystis.
Q38. Bryophytes are called _____ of plant kingdom.
Answer: Amphibians.
Q39. First vascular plants are _____.
Answer: Pteridophytes.
Q40. Double fertilization occurs in _____.
Answer: Angiosperms.
Q41. Fucoxanthin is found in _____.
Answer: Brown algae.
Q42. Agar is obtained from _____.
Answer: Red algae.
Q43. Haploid phase in plants is called _____.
Answer: Gametophyte.
Q44. Diploid phase in plants is called _____.
Answer: Sporophyte.
Q45. Gametophyte dominant plants are _____.
Answer: Bryophytes.
Q46. Sporophyte dominant plants are _____.
Answer: Pteridophytes, Gymnosperms, Angiosperms.
Q47. Motile male gamete in bryophytes is called _____.
Answer: Antherozoid.
Q48. First naked seed plant is _____.
Answer: Gymnosperms.
Q49. Chlorophyll a and d are found in _____.
Answer: Red algae.
Q50. Algae used in space food is _____.
Answer: Chlorella.
Q51. Male organ of bryophytes is _____.
Answer: Antheridium.
Q52. Female organ of bryophytes is _____.
Answer: Archegonium.
Q53. Vascular cryptogams include _____.
Answer: Pteridophytes.
Q54. Non-vascular plants include _____.
Answer: Bryophytes.
Q55. Gymnosperms are called naked seed because _____.
Answer: Seeds are not enclosed in fruit.
Q56. Example of heterosporous pteridophyte is _____.
Answer: Selaginella.
Q57. Dominant phase in ferns is _____.
Answer: Sporophyte.
Q58. Smallest angiosperm is _____.
Answer: Wolffia.
Q59. Non-motile gametes are in _____.
Answer: Red algae.
Q60. Pollen tube delivery of male gamete is called _____.
Answer: Siphonogamy.
C. One Liner Questions (20)–Q61 to Q80
Q61. Which bryophyte is used as packing material?
Answer: Sphagnum moss is used as packing material, fuel, and soil conditioner. It can absorb large amounts of water, thus preventing decay of goods. Also called peat moss, partially decomposed Sphagnum forms peat used as fuel.
Q62. First vascular plants are?
Answer: Pteridophytes (ferns, horsetails, club mosses). They have xylem and phloem, which helps in water and food transport. They represent the first true land plants with vascular tissue.
Q63. Example of living fossil gymnosperm.
Answer: Ginkgo biloba, a gymnosperm with unchanged features for millions of years. Dioecious, fan-shaped leaves, seeds naked, resistant to pollution.
Q64. Male gametes of bryophytes are called?
Answer: Antherozoids, motile sperm with flagella, require water for fertilization.
Q65. Largest algae?
Answer: Macrocystis, brown algae growing up to 60–100 meters in length.
Q66. Homosporous pteridophytes produce?
Answer: One type of spore → develops into bisexual gametophyte.
Example: Pteris.
Q67. Heterosporous pteridophytes produce?
Answer: Two types of spores: microspores (male) and megaspores (female).
Example: Selaginella, Salvinia.
Q68. Algae used in space food.
Answer: Chlorella, unicellular green alga, high in protein and vitamins, tested for astronauts’ nutrition.
Q69. Non-motile gametes are found in?
Answer: Red algae, no flagella, fertilization occurs by fusion in water or in surrounding gelatinous layer.
Q70. Vascular cryptogams include?
Answer: Pteridophytes, sporophyte dominant, vascular tissue present, reproduce via spores.
Q71. Non-vascular plants include?
Answer: Bryophytes, no true xylem or phloem, small, gametophyte dominant.
Q72. Gymnosperms are called naked seed because?
Answer: Seeds are exposed on megasporophylls, not enclosed in fruit. Example: Pinus, Cycas.
Q73. Dominant phase in bryophytes?
Answer: Gametophyte, green, photosynthetic, independent. Sporophyte is dependent.
Q74. Dominant phase in pteridophytes?
Answer: Sporophyte, free-living, larger, produces spores.
Q75. Stored food in brown algae is?
Answer: Mannitol and laminarin, helps survive low light and energy storage.
Q76. Example of heterosporous pteridophyte?
Answer: Selaginella, produces microspores (male) and megaspores (female).
Q77. Pollen tube delivery of male gamete is called?
Answer: Siphonogamy, characteristic of gymnosperms and angiosperms.
Q78. Algae with chlorophyll a and d?
Answer: Red algae (Rhodophyceae), pigments mask chlorophyll, red colour due to phycoerythrin.
Q79. Male organ of bryophytes?
Answer: Antheridium, produces motile sperm.
Q80. Female organ of bryophytes?
Answer: Archegonium, multicellular, produces egg cell, protects it until fertilization.
D. Long Answer Questions (NCERT Language) – Q81 to Q100
Q81. Explain Double Fertilization in Angiosperms.
Answer: Double fertilization is a unique characteristic of angiosperms. In this process, two male gametes from the pollen grain participate in fertilization:
1. One male gamete fuses with the egg cell to form the diploid zygote (2n), which develops into the embryo.
2. The other male gamete fuses with the two polar nuclei present in the embryo sac to form the triploid endosperm (3n), which serves as nutritive tissue for the developing embryo.
This process ensures the proper nutrition for the embryo and is crucial for seed development. Double fertilization was first discovered by Nawaschin in 1898.
Q82. Why are Bryophytes called Amphibians of Plant Kingdom?
Answer: Bryophytes are called amphibians of the plant kingdom because they exhibit characteristics of both aquatic and terrestrial plants:
They grow on land but require water for fertilization, as their male gametes (antherozoids) are motile. The gametophyte is dominant and photosynthetic, whereas the sporophyte is dependent on the gametophyte. They represent the transition from algae to higher terrestrial plants. Example: Funaria, Marchantia.
Q83. Discuss the economic importance of algae.
Answer: Algae are economically important in several ways:
1. Food: Red algae (Porphyra – nori), green algae (Chlorella) are edible and rich in protein.
2. Industrial uses: Agar and carrageenan (from red algae) are used in food, pharmaceuticals, and microbiological media.
3. Medicinal use: Algae provide vitamins, antioxidants, and compounds used in health supplements.
4. Environmental: Algae produce oxygen, help in carbon fixation, and are used in wastewater treatment.
5. Biofuel: Some algae are explored for production of biodiesel due to high lipid content.
Q84. Explain the life cycle of Chlamydomonas.
Answer: Chlamydomonas is a unicellular green alga exhibiting a haplontic life cycle.
Asexual reproduction: occurs through zoospores, which are motile and haploid.
Sexual reproduction: under unfavorable conditions, two haploid gametes fuse to form a zygote (diploid).
The zygote undergoes meiosis, giving rise to haploid cells. This life cycle shows alternation of generations at cellular level.
Q85. Explain the structure and reproduction in Selaginella.
Answer: Selaginella is a heterosporous pteridophyte. Sporophyte: dominant and vascular; produces microspores (male) and megaspores (female) in separate microsporangia and megasporangia.
Microspores germinate to form male gametophytes, and megaspores develop into female gametophytes.
Fertilization leads to zygote and new sporophyte formation. Shows strobilus formation and represents the evolutionary link to seed habit.
Q86. Describe the salient features of Gymnosperms.
Answer: Gymnosperms are naked-seeded, vascular, and mostly woody plants: Seeds are exposed, not enclosed in fruit. Sporophyte is dominant, long-lived, and photosynthetic. Pollination occurs by wind; fertilization via pollen tube (siphonogamy). Leaves are usually needle-like or scale-like. Examples: Pinus, Cycas, Ginkgo biloba.
Economic importance: timber, resin, medicines, ornamental plants.
Q87. Describe the structure of Cycas.
Answer: Cycas is a dioecious gymnosperm (male and female plants separate).
Roots: coralloid and symbiotic with nitrogen-fixing cyanobacteria.
Leaves: pinnate, leathery.
Male plant: produces cone-like structure called microstrobilus, bearing microsporophylls with pollen.
Female plant: produces megasporophylls with exposed ovules. Seeds are naked, large, and fleshy. Called a living fossil because of ancient origin and unchanged morphology.
Q88. Explain the life cycle of a fern (Dryopteris).
Answer: Ferns are vascular cryptogams with sporophyte dominant:
1. Sporophyte: large, photosynthetic plant; produces haploid spores on the underside of fronds (sporangia in sori).
2. Gametophyte (Prothallus): small, haploid, heart-shaped structure; produces antheridia (male) and archegonia (female).
3. Fertilization requires water; antherozoids swim to egg → zygote formed.
4. Zygote develops into new sporophyte, completing the life cycle.
Q89. Explain alternation of generations in plants.
Answer: Alternation of generations refers to the regular alternation of haploid (gametophyte) and diploid (sporophyte) phases.
Examples:
Bryophytes: gametophyte dominant, sporophyte dependent.
Pteridophytes: sporophyte dominant, gametophyte small, independent.
Angiosperms: sporophyte dominant, gametophyte reduced (embryo sac and pollen).
This phenomenon shows the evolutionary trend from gametophyte dominance to sporophyte dominance in higher plants.
Q90. Mention adaptations of Bryophytes to land environment.
Answer: 1. Cuticle prevents water loss.
2. Rhizoids anchor plant.
3. Multicellular sex organs (antheridium, archegonium) protect gametes.
4. Spores with resistant walls survive adverse conditions.
5. Ability to absorb water quickly from the environment.Q91. Describe the economic importance of Gymnosperms.
Answer: Timber: Pinus, Cedrus, used for construction.
Resin: turpentine, rosin.
Medicinal uses: ephedrine from Ephedra, anti-cancer drugs.
Ornamental plants: Ginkgo, Cycas.
Paper and pulp production: some gymnosperms are used for making paper.
Q92. Explain the haplodiplontic life cycle with examples.
Answer: In haplodiplontic life cycle, both gametophyte (haploid) and sporophyte (diploid) are multicellular.
Examples: Ferns, Mosses, Selaginella.
Gametophyte produces gametes → fertilization → zygote → sporophyte.
Sporophyte produces spores by meiosis → haploid gametophyte develops.
Q93. List features of Angiosperms.
Answer: Flowers for sexual reproduction. Seeds enclosed in fruit. Double fertilization forms zygote and endosperm. Advanced vascular tissue with xylem vessels and phloem.
Examples: Mango, Rose, Wheat.
Q94. List salient features of Pteridophytes.
Answer: True vascular plants; have xylem and phloem. Sporophyte is dominant; gametophyte small and independent. Reproduce via spores (homosporous or heterosporous).
Examples: Fern (Dryopteris), Club moss (Selaginella), Horsetail (Equisetum).
Q95. Differentiate between Gymnosperms and Angiosperms.
Answer: Feature Gymnosperms Angiosperms
Seeds Naked Enclosed in fruit
Fertilization Single Doublep0
Flowers Absent Present
Vascular tissue Tracheids only Tracheids + vessels
Examples Pinus, Cycas Rose, Mango
Q96. Explain the structure of male gametophyte in Angiosperms.
Answer: Male gametophyte is the pollen grain. Consists of two cells: Vegetative
cell: forms pollen tube.
Generative cell: divides to produce two male gametes.
Pollen wall: outer exine, inner intine. Adapted for dispersal by wind, insects, or water.
Q97. Define Strobilus with example.
Answer: Strobilus is a cone-like structure bearing sporophylls.
By- B.K. SAMOTYA SIR
Youtube- @biologybybk
( Urmila science academy )
Blog - 1. Omnibiora.blogspot.com
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nice 1 b.k. sir
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