Chapter 8
Kingdom Plantae
Section I: Multiple Choice Questions
1. Plants are thought to have descended from a common protistan ancestor
ancient...
Answer: (A) Freshwater algae
2. Gametophyte in bryophytes is:
Answer: (A) Haploid
3. Whisk ferns belong to the group:
Answer: (C) Psilopsida
4. Sago grains are obtained from:
Answer: (A) Cycas
5. These are highly evolved of all the plants on Earth:
Answer: (D) Angiosperms
6. Moss plants develop from:
Answer: (B) Protonema
7. Fern plant is:
Answer: (A) Diploid sporophyte
8. Which of the following parts of the flower is transformed into seeds after
fertilization?
Answer: (C) Ovary
9. Gymnosperms are characterized by:
Answer: (B) Naked seeds
10. Where a megasporangium is present in an angiosperm?
Answer: (B) Within an ovule
11. Gametophyte generation is dominant in:
Answer: (C) Bryophytes
12. Which part of the angiospermic plant is parallel to the cones of Gymnospermic
plants?
Answer: (B) Ovary
13. Which part of the angiospermic plant is parallel to the cones of Gymnospermic
plants?
Answer: (D) Ovule
14. Fibers obtained from the leaves of ___________, which is used in making
ropes:
Answer: (C) Saccharum munja
15. Which of the following is correct about the labeling of the diagram?
Answer: (C) Seed → Flower → Mature plant → Young plant → Fruit
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Section II: Short Questions
1. How are cones and flowers alike? How are they different?
Cones and flowers are reproductive structures in plants, but they differ
significantly in their organization. Cones, found in gymnosperms, are simpler
structures consisting of scales that bear seeds or pollen. Flowers, found in
angiosperms, are more complex, containing sepals, petals, stamens, and carpels.
Both structures serve to facilitate reproduction, but flowers have an advanced
mechanism for pollination and seed dispersal due to the involvement of insects
and other pollinators, whereas cones rely mostly on wind.
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2. What is the importance of alternation of generation, pollen tube, and seed?
The alternation of generation ensures genetic variation and adaptation by
alternating between haploid (gametophyte) and diploid (sporophyte) stages in
plant life cycles.
The pollen tube facilitates the transfer of male gametes to the ovule for
fertilization, ensuring the formation of seeds. Seeds play a crucial role in
protecting the developing embryo, providing nutrients, and enabling dispersal to
new environments.
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3. Write three main features of bryophytes.
1. Dominant gametophyte: The gametophyte is the prominent phase in the
bryophyte life cycle.
2. Non-vascular plants: They lack xylem and phloem, relying on diffusion for water
and nutrient transport.
3. Moist habitat requirement: Bryophytes require a damp environment for
reproduction, as sperm cells swim to the egg.
These features distinguish bryophytes from higher plants.
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4. Name the land adaptation features of bryophytes.
Bryophytes exhibit several adaptations to terrestrial life, including:
Waxy cuticle: Reduces water loss.
Rhizoids: Anchor the plant and absorb water and nutrients.
Spores: Resistant to desiccation, aiding in reproduction.
However, their reliance on water for reproduction limits their distribution to
moist habitats.
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5. Write any four features of vascular plants.
1. Presence of vascular tissues: Xylem and phloem for water and nutrient
transport.
2. Roots, stems, and leaves: Specialized organs for support, photosynthesis, and
nutrient absorption.
3. Dominant sporophyte phase: The diploid phase is the main stage of the life
cycle.
4. Adaptation to land: Cuticle and stomata reduce water loss.
These features make vascular plants well-suited to diverse terrestrial
environments.
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6. Why are bryophytes called amphibious plants?
Bryophytes are called amphibious plants because they live on land but require
water for reproduction. Male gametes (sperm) swim to reach female gametes
(egg) for fertilization.
This dual requirement for terrestrial and aquatic conditions makes them
dependent on moist environments.
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7. Give one example of: Whisk ferns, club mosses, horsetails, and ferns.
1. Whisk ferns: Psilotum
2. Club mosses: Lycopodium
3. Horsetails: Equisetum
4. Ferns: Adiantum
These examples represent different groups of seedless vascular plants.
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8. Draw and label the life cycle of a fern.
The life cycle of a fern involves alternation of generations:
Sporophyte phase: The dominant phase, producing spores in sporangia.
Gametophyte phase: The haploid phase, producing male and female gametes.
(Note: A detailed drawing would include the sporophyte, gametophyte, sporangia,
and fertilization process, with arrows showing the cycle.)
9. What is the importance of seedless vascular plants?
Seedless vascular plants, like ferns and horsetails, play a vital ecological role in
maintaining ecosystems. They contribute to soil formation by breaking down rocks
and adding organic matter through decomposition.
Additionally, they act as carbon sinks, reducing carbon dioxide levels in the
atmosphere, and provide habitat and food for various organisms. Historically,
they formed extensive forests, contributing to the formation of coal deposits.
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10. Write botanical names and families of the following plants.
1. Rice: Botanical Name - Oryza sativa; Family - Poaceae
2. Potato: Botanical Name - Solanum tuberosum; Family - Solanaceae
3. Sugarcane: Botanical Name - Saccharum officinarum; Family - Poaceae
These plants are economically significant as staple foods and industrial crops.
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11. Write any four uses of bryophytes and gymnosperms.
1. Bryophytes:
Act as soil stabilizers by reducing erosion.
Provide habitat for small organisms.
Used as bioindicators of air and water quality.
Serve as a water reservoir in ecosystems.
2. Gymnosperms:
Source of timber and paper (e.g., pine trees).
Produce resins used in varnishes and adhesives.
Provide ornamental plants for landscaping.
Source of edible seeds (e.g., pine nuts).
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12. Define: Angiosperms, inflorescence, and alternation of generation.
1. Angiosperms: Flowering plants that produce seeds enclosed within fruits,
representing the most advanced group of plants.
2. Inflorescence: The arrangement of flowers on a plant’s stem or branch,
enhancing pollination efficiency.
3. Alternation of Generation: The life cycle alternates between a haploid
gametophyte phase and a diploid sporophyte phase, ensuring genetic diversity.
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13. What is the advantage of the seed?
Seeds provide several advantages:
1. Protection: The seed coat shields the embryo from harsh environmental
conditions.
2. Nutrition: Seeds contain stored food, aiding in early growth.
3. Dispersal: Seeds enable plants to spread to new areas through wind, water, or
animals.
These features enhance plant survival and reproduction in diverse habitats.
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14. What do monocots and dicots have in common? How do they differ?
Common Features:
Both are flowering plants (angiosperms).
They produce seeds and exhibit alternation of generations.
Differences:
Monocots have a single cotyledon, parallel leaf venation, and fibrous roots, while
dicots have two cotyledons, reticulate venation, and taproots.
Floral parts in monocots are in multiples of three, while in dicots, they are in
multiples of four or five.
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15. Give three reasons to justify that the following plant is a monocot.
The plant illustrated is a monocot due to:
1. Parallel venation: Leaves show parallel arrangement of veins.
2. Fibrous root system: Absence of a primary taproot.
3. Floral structure: Parts arranged in multiples of three.
These features are typical of monocots like grasses, lilies, and orchids.
Section III: Extensive Answer Questions
1. List the diagnostic features shared by all plants, with emphasis on alternation
of generation.
Plants are multicellular eukaryotes characterized by their ability to perform
photosynthesis using chlorophyll. One key feature is the presence of cell walls
made of cellulose, providing structural support.
A unique trait of plants is alternation of generation, where the life cycle
alternates between a diploid sporophyte stage and a haploid gametophyte stage.
This alternation ensures genetic variation and adaptation to diverse
environments.
Additionally, plants exhibit adaptations like vascular tissues, seeds, or spores to
survive on land. They also display sexual reproduction, involving specialized
reproductive structures such as flowers or cones.
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2. Describe the general characteristics of bryophytes.
Bryophytes are non-vascular plants that include mosses, liverworts, and
hornworts. They lack xylem and phloem, relying on diffusion for water and
nutrient transport.
The gametophyte is the dominant phase, with the sporophyte being dependent on
it. Bryophytes require moist environments for reproduction, as their sperm cells
need water to swim to the egg.
Ecologically, bryophytes prevent soil erosion and act as bioindicators of
environmental health. They are also pioneers in colonizing barren habitats, aiding
in soil formation.
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3. Describe the life cycle of moss.
The life cycle of moss exhibits alternation of generations, with the gametophyte
being the dominant phase. The gametophyte produces male (antheridia) and
female (archegonia) reproductive organs.
Fertilization occurs when sperm cells from the antheridia swim to the egg in the
archegonia, forming a diploid zygote. The zygote develops into a sporophyte,
which remains attached to the gametophyte and produces spores through meiosis.
These spores germinate into new gametophytes, completing the cycle. This
dependency on water for reproduction limits mosses to moist environments.
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4. Explain the land adaptations of bryophytes.
Bryophytes have evolved several adaptations to terrestrial life. They possess a
waxy cuticle that reduces water loss and rhizoids that anchor them to the
substrate.
Their spores are resistant to desiccation, enabling dispersal and survival in dry
conditions. Bryophytes also exhibit alternation of generations, which helps in
adapting to varying environments.
However, their reliance on water for reproduction and lack of vascular tissues
restrict their distribution to moist habitats.
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5. Describe the general characteristics of vascular plants.
Vascular plants, including ferns, gymnosperms, and angiosperms, possess
specialized tissues: xylem for water conduction and phloem for nutrient
transport. These tissues allow efficient resource distribution and growth in
diverse habitats.
They have well-differentiated organs: roots for anchorage and nutrient
absorption, stems for support, and leaves for photosynthesis. The sporophyte
phase dominates their life cycle, with the gametophyte being reduced.
Vascular plants are adapted to terrestrial environments, with structures like
cuticles, stomata, and seeds enabling survival and reproduction.
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6. List the characteristics of seedless vascular plants with examples of whisk
ferns, club mosses, horsetails, and ferns.
Seedless vascular plants reproduce via spores instead of seeds and include:
1. Whisk ferns (e.g., Psilotum): Lack true roots and leaves but have vascular
tissues.
2. Club mosses (e.g., Lycopodium): Possess small leaves called microphylls.
3. Horsetails (e.g., Equisetum): Have jointed stems with silica deposits.
4. Ferns (e.g., Adiantum): Exhibit large, divided leaves called fronds.
These plants thrive in moist environments and contribute to soil formation and
carbon cycling.
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7. Describe the life cycle of fern (Adiantum).
The fern life cycle alternates between a dominant diploid sporophyte and a
haploid gametophyte. The sporophyte produces spores in sporangia located on the
underside of fronds.
Spores germinate into heart-shaped gametophytes, which produce antheridia
(male organs) and archegonia (female organs). Fertilization occurs when sperm
swims to the egg, forming a zygote.
The zygote grows into a new sporophyte, completing the cycle. Ferns require
water for reproduction, limiting their distribution to moist habitats.
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8. Describe vascular plants as successful land plants.
Vascular plants are highly successful on land due to their advanced adaptations.
The presence of xylem and phloem enables efficient water and nutrient transport,
supporting growth in diverse environments.
They have specialized organs: roots anchor plants and absorb nutrients, stems
provide support, and leaves maximize photosynthesis. Protective structures like
cuticles and stomata reduce water loss.
Additionally, seeds and flowers in higher vascular plants ensure effective
reproduction and dispersal, further enhancing their success.
9. Summarize the importance of seedless vascular plants.
Seedless vascular plants, such as ferns, horsetails, and club mosses, play a
significant ecological role. They contribute to the formation of soil by breaking
down rocks and adding organic matter through decomposition.
These plants serve as pioneers in barren areas, creating conditions favorable for
other species. Historically, they formed extensive forests that contributed to
the formation of coal deposits, which are essential energy sources today.
Their presence in ecosystems helps stabilize water cycles and provide habitats
for diverse organisms, showcasing their importance in maintaining ecological
balance.
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10. Describe the general characteristics and uses of gymnosperms.
Gymnosperms are non-flowering plants characterized by naked seeds not enclosed
in fruits. They possess vascular tissues, with xylem containing tracheids and
phloem lacking companion cells. The dominant phase in their life cycle is the
diploid sporophyte.
Gymnosperms have significant economic and ecological importance. They provide
timber, resins, and edible seeds like pine nuts. They are used in landscaping and
serve as a source of paper pulp. Ecologically, gymnosperms contribute to oxygen
production and act as carbon sinks, mitigating climate change.
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11. Define angiosperms and explain the diversity.
Angiosperms, or flowering plants, are the most diverse group of plants,
characterized by seeds enclosed within fruits. They exhibit a wide range of
forms, from tiny herbs to massive trees.
Their diversity arises from adaptations like specialized pollination mechanisms
involving insects, birds, or wind. Angiosperms dominate terrestrial ecosystems
due to their efficient vascular systems, seeds, and fruits, which aid in
reproduction and dispersal.
Examples include monocots like grasses and dicots like oaks, showcasing their
adaptability to various environments.
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12. Describe the life cycle of a flowering plant.
The life cycle of a flowering plant alternates between the diploid sporophyte and
haploid gametophyte generations. The sporophyte produces flowers, which
contain male (stamens) and female (carpels) reproductive organs.
Male gametes (pollen) are transferred to the female ovule via pollination, leading
to fertilization. The zygote develops into an embryo, forming a seed. Seeds
germinate under favorable conditions, giving rise to a new sporophyte.
This cycle ensures genetic variation and adaptation to diverse environments.
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13. Explain how the life cycle of an angiosperm demonstrates an adaptation of
angiosperms on land.
The angiosperm life cycle includes several adaptations for terrestrial life. The
development of flowers and enclosed seeds provides protection to gametes and
embryos. Pollination mechanisms ensure effective transfer of gametes, reducing
reliance on water.
Fruits aid in seed dispersal, enabling colonization of new areas. The vascular
system supports efficient nutrient and water transport, while roots anchor the
plant and absorb nutrients. These features make angiosperms highly adapted to
diverse terrestrial habitats.
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14. Describe the significance/benefits of angiosperms for humans.
Angiosperms are crucial for human survival and well-being. They provide staple
foods like rice, wheat, and maize, as well as fruits and vegetables. They are a
source of medicines, including drugs like aspirin and quinine.
In addition to food and medicine, angiosperms provide raw materials for clothing
(cotton), shelter (timber), and fuel (bioenergy crops). Their aesthetic value is
evident in ornamental plants and flowers. Angiosperms also play a role in
ecosystem services like oxygen production and climate regulation.
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15. Describe the advantages of seeds in plants.
Seeds provide several advantages for plants, ensuring their survival and
reproduction. They protect the embryo with a tough seed coat, shielding it from
environmental stresses. Seeds also contain stored food, enabling the young plant
to grow until it can perform photosynthesis.
Additionally, seeds facilitate dispersal to new habitats through mechanisms like
wind, water, and animal carriers. This dispersal reduces competition among
offspring and increases genetic diversity, enhancing the adaptability of plant
species.
