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Chapter Analysis
Intermediate13 pages • EnglishQuick Summary
The chapter 'Plant Kingdom' in Class 11 Biology covers the classification of plants including algae, bryophytes, pteridophytes, gymnosperms, and angiosperms. Algae, as simple chlorophyll-bearing organisms, play a vital role in the ecosystem and are classified into three types: Chlorophyceae, Phaeophyceae, and Rhodophyceae. Bryophytes represent non-vascular plants like mosses and liverworts, requiring water for sexual reproduction. Pteridophytes are vascular plants with distinct reproductive structures and are precursors to seed formation. Gymnosperms are seed-producing plants with unenclosed seeds, and angiosperms are characterized by their floral structures and seeds enclosed within fruits.
Key Topics
- •Classification of Algae
- •Bryophytes and their lifecycle
- •Characteristics of Pteridophytes
- •Adaptations of Gymnosperms
- •Diversity and Features of Angiosperms
- •Economic and ecological roles of algae
- •Reproductive strategies in plant kingdom
- •Phylogenetic classification systems
Learning Objectives
- ✓Understand the classification within the plant kingdom.
- ✓Identify the key characteristics of algae, bryophytes, pteridophytes, gymnosperms, and angiosperms.
- ✓Explain the reproduction and lifecycle of different plant groups.
- ✓Analyze the economic and ecological importance of aquatic and terrestrial plants.
- ✓Differentiate between seed-bearing and non-seed-bearing plants.
- ✓Explore phylogenetic relationships among major plant groups.
Questions in Chapter
What is the basis of classification of algae?
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When and where does reduction division take place in the life cycle of a liverwort, a moss, a fern, a gymnosperm and an angiosperm?
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Name three groups of plants that bear archegonia. Briefly describe the life cycle of any one of them.
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Mention the ploidy of the following: protonemal cell of a moss; primary endosperm nucleus in dicot, leaf cell of a moss; prothallus cell of a fern; gemma cell in Marchantia; meristem cell of monocot, ovum of a liverwort, and zygote of a fern.
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Write a note on economic importance of algae and gymnosperms.
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Both gymnosperms and angiosperms bear seeds, then why are they classified separately?
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What is heterospory? Briefly comment on its significance. Give two examples.
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Explain briefly the following terms with suitable examples: protonema, antheridium, archegonium, diplontic, sporophyll, isogamy.
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Differentiate between the following: red algae and brown algae, liverworts and moss, homosporous and heterosporous pteridophyte.
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Match the following (column I with column II). Column I: Chlamydomonas, Cycas, Selaginella, Sphagnum. Column II: Moss, Pteridophyte, Algae, Gymnosperm.
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Describe the important characteristics of gymnosperms.
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Additional Practice Questions
Describe the life cycle of a typical fern.
mediumAnswer: The life cycle of a fern includes a dominant sporophyte stage and a smaller, independent gametophyte stage. Sporophytes produce spores via meiosis in sporangia. These spores germinate into gametophytes, which bear the reproductive organs. Fertilization occurs when sperms swim to the eggs, forming a zygote that grows into a new sporophyte.
What role do bryophytes play in preventing soil erosion?
easyAnswer: Bryophytes, such as mosses, form dense mats on the soil, which helps in minimizing the impact of rainfall, thus reducing soil erosion. They contribute organic matter, improving soil structure.
Explain how gymnosperms adapt to dry conditions.
mediumAnswer: Gymnosperms possess adaptations such as needle-like leaves with a thick cuticle and sunken stomata, reducing water loss. These adaptations enable them to live in dry and cold conditions.
Differentiate between homosporous and heterosporous plants with examples.
mediumAnswer: Homosporous plants produce one type of spore that develops into a bisexual gametophyte, e.g., ferns like Pteris. Heterosporous plants produce microspores and megaspores that form male and female gametophytes, respectively, e.g., Selaginella and Salvinia.
Discuss the economic importance of algae.
mediumAnswer: Algae are vital for carbon fixation and oxygen production. They are used in food, e.g., as agar and carrageenan, and have applications in pharmaceuticals, agriculture, and biofuel industries.
List the key characteristics that differentiate angiosperms from gymnosperms.
hardAnswer: Angiosperms bear seeds enclosed within fruits, have flowers as reproductive structures, and exhibit double fertilization, unlike gymnosperms, which have naked seeds and no flowers.
Explain the significance of vascular tissues in pteridophytes.
mediumAnswer: Vascular tissues, xylem, and phloem enable efficient water and nutrient transport, support growth, and allow pteridophytes to thrive in varied terrestrial environments.
How do red algae adapt to deep ocean environments?
mediumAnswer: Red algae have the pigment phycoerythrin, which allows them to absorb blue light, penetrating deeper waters, enabling photosynthesis at great depths.
Describe the commercial applications of specific brown algae.
hardAnswer: Brown algae such as Laminaria and Sargassum are sources of alginates, used in food industry as thickeners, and in textiles and pharmaceuticals.
Discuss the ecological role of ferns within their environment.
hardAnswer: Ferns aid in soil formation, prevent erosion, provide habitat and food for wildlife, and play a role in nutrient cycling in forest ecosystems.
NCERT Exemplar
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