Plant Biodiversity classifications life cycles.pptx

1. Plant Biodiversity

2. Classification of Plants

3. ALGAE
Chlorophyceae
(green algae)
Rhodophyceae
(red algae)
Phaeophyceae
(brown algae)
The Kingdom Plantae includes a diverse range of multicellular, photosynthetic
organisms, including some groups of algae.
Algae classes that are typically classified within the Kingdom Plantae include
Chlorophyceae (green algae), Rhodophyceae (red algae), and Phaeophyceae
(brown algae).
For example:
• Chlorophyceae (green algae) such as Spirogyra and Ulva.
• Rhodophyceae (red algae) such as Corallina and Gelidium.
• Phaeophyceae (brown algae) such as Sargassum and Laminaria.
“Thallophytes" is a term used in botanical classification to refer to a group of plants characterized by
having a thallus. A thallus is a simple, undifferentiated body structure that lacks true roots, stems, and
leaves. Thallophytes are considered more primitive in their organization compared to higher plants, which
have more complex structures and specialized tissues.

4. ALGAE
Algae are mostly aquatic, some being terrestrial
also.
A few algae grow on other plants.
Aquatic algae grow in marine water or fresh water
They may be small, unicellular, microscopic like
Chlorella (non-motile), Chlamydomonas (motile)
or multicellular unbranched filamentous like
Spirogyra and Ulothrix,
or branched filamentous like Chara
or colonial forms like Volvox
or huge macro-scopic such as
sea weeds which measure more than 60 meters in
length. e.g. Sargassum

5. At least a half of the total carbon dioxide fixation on earth is carried out by algae through
photosynthesis
Being photosynthetic they increase the level of dissolved oxygen in their immediate
environment.
They are of paramount importance as primary producers of energy-rich compounds which
form the basis of the food cycles of all aquatic animals.
Many species of Porphyra, Laminaria and Sargassumare among the 70 species of marine
algae used as food.
Certain marine brown and red algae produce large amounts of hydrocolloids (water
holding substances), e.g., algin (brown algae) and carrageen (red algae) are used
commercially
Agar, one of the commercial products obtained from Gelidium and Gracilaria are used to
grow microbes and in preparations of ice-creams and jellies.
Chlorella and Spirullina are unicellular algae, rich in proteins and are used as food
supplements.

6. BRYOPHYTA
Mostly terrestrial plantswhich depend on
external water for fertilization and completion
of their life cycle.
Hence they are called `amphibian plants'
Grow in shady and moist places such as moist
walls, damp rocks, moist soil and on decaying
logs.
They show thalloid plant body which is not
differentiated into root, stem and leaves.
In Bryophytes true roots are absent but
rhizoids are present.
Rhizoids are unicellular in liverworts, while
multicellular in mosses.
They absorb water and minerals and also help
in fixation of thallus to the substratum.

7. BRYOPHYTA

8. called
and
The main plant body(thallus) of the
bryophyte is haploid.
It produces gametes, hence is called a
gametophyte
The sex organs in bryophytes are
multicellular.
The male sex organ is called
antheridium. They produce biflagellate
antherozoids.
The female sex organ
archegonium is flask-shaped
produces a single egg.
The antherozoids are released into
water where they come in contact with
archegonium. An antherozoid fuses with
the egg to produce the zygote.
The gametophyte is the dominant,
green, haploid and independent
phase.
GAMETOPHYTE
The zygote produces a multicellular body
called a sporophyte.
The sporophyte is not free-living but
attached to the photosynthetic
gametophyte and derives nourishment
from it.
Some cells of the sporophyte undergo
reduction division (meiosis) to produce
haploid spores.
These spores germinate to produce
gametophyte.
Thus, the sporophyte is diploid,
recessive and partially dependent on
gametophyte
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SPOROPHYTE

9. 1. Some mosses provide food for herbaceous mammals, birds and other
animals.
2. Species of Sphagnum, a moss, provide peat that have long been used as
fuel, and because of their capacity to hold water as packing material for trans-
shipment of living material.
3. Mosses, along with lichens are the first organisms to colonise rocks and
hence, are of great ecological importance. They decompose rocks making the
substrate suitable for the growth of higher plants.
4. Since mosses form dense mats on the soil, they reduce the impact of falling
rain and prevent soil erosion
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Economic Importance of Bryophytes

10. PTERIDOPHYTA
The first vascular plants and the first successful
terrestrial plants with true roots, stem and
leaves but no flowers fruits and seeds
Called as VASCULAR CRYPTOGAMS
The Pteridophytes include horsetails and ferns.
The Pteridophytes are terrestrial, small, either
annual or perennial, and grow luxuriantly in
cool, moist and shady places. e.g. ferns.
They may be aquatic(Azolla, Marsilea),
xerophytic(Equisetum)
epiphytic(Lycopodium) i.e.
growing on large trunks of trees

11. PTERIDOPHYTA Plant Body
The primary root is short-lived and is soon replaced
by adventitious roots
Stem may be aerial or underground.
The leaves may be scaly (Equisetum),
simple and sessile (Lycopodium)
or large and pinnately compound (Ferns).
The leaves in pteridophyta are small(microphylls) as
in Selaginella or large(macrophylls) as in Ferns.
In pteridophytes, the xylem consists of only tracheids
and phloem consists of sieve cells only.
Secondary growth is not seen in Pteridophytes
dueto absence of cambium.

12. PTERIDOPHYTA HETEROMORPHIC ALTERNATION OF GENERATION

13. The sporophyte shows asexual reproduction and produces spores by meiosis from which the
gametophyte develops.
The gametophyte is haploid,recessive but independent, and reproduces sexually.
Product of sexual reproduction, i.e. zygote produces diploid sporophyte.
Spores are produced in special multicellular structures called sporangia.The sporangia are
produced by leaf-like appendages called sporophylls.
structures called strobili or
In some cases,sporophylls may form distinct compact
cones(Selaginella, Equisetum).
The sporangia produce spores by meiosis in spore mother cells.
The spores germinate to give rise to inconspicuous, small but multicellular, free-living, mostly
photosynthetic thalloid gametophytes called prothallus.
PTERIDOPHYTA REPRODUCTION

14. These gametophytes require cool, damp, shady places to grow.
The gametophytes bear male and female sex organs called
antheridia and archegonia, respectively.
Water is required for transfer of antherozoids - the male gametes released from the
antheridia, to the mouth of archegonium.
Fusion of male gamete with the egg present in the archegonium result in the
formation of zygote.
Zygote thereafter produces a multicellular well-differentiated sporophyte which is
the dominant phase of the pteridophytes. In majority of the pteridophytes, all the
spores are of similar kinds; such plants are called homosporous. Genera like
Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro
(small) spores, are known as heterosporous. The megaspores and microspores
germinate and give rise to female and male gametophytes, respectively. The female
gametophytes in these plants are retained on the parent sporophytes for variable
periods. The development of the zygotes into young embryos take place within the
female gametophytes.

15. 1. Ornamental Plants: Many species of ferns are valued for their ornamental qualities and are used in
landscaping, indoor decoration, and floral arrangements. Varieties such as Boston ferns, maidenhair ferns,
and staghorn ferns are popular choices for adding greenery to gardens, homes, and public spaces.
2. Erosion Control and Landscaping: Some species of ferns are effective in stabilizing soil and preventing
erosion on slopes, riverbanks, and disturbed landscapes. They are used in reforestation projects, land
rehabilitation efforts, and landscaping to restore vegetation cover and maintain ecosystem health.
3. Traditional Medicine: In some cultures, certain fern species have been used in traditional medicine for their
purported medicinal properties. Although scientific evidence supporting their efficacy is limited, ferns have
been used historically to treat ailments such as digestive disorders, skin conditions, and respiratory illnesses.
4. Ecological Restoration: Ferns play a role in ecological restoration and habitat rehabilitation projects aimed at
restoring degraded ecosystems, such as wetlands, forests, and riparian areas. They are often included in
revegetation plans to enhance biodiversity, stabilize soils, and create habitat for wildlife.
5. Bioindicators and Phytoremediation: Some fern species have the ability to accumulate heavy metals and
other pollutants from soil and water, making them potentially useful in phytoremediation efforts to clean up
contaminated sites. Ferns can also serve as bioindicators of soil pollution and environmental degradation.
Economic Importance of Pteridophytes

16. The plant body i.e. sporophyte is differentiated into
root, stem and leaves
ROOTS :
Specialized Coralloid roots of Cycas show association with N2-
fixing blue-green algae and
Pinus show association with endophytic fungi called
mycorrhizae
STEM :
The gymnospermic stem is mostly erect, aerial, solid and
cylindrical.
In Cycas, it is unbranched, while in
Pinus, Cedrus and conifers it is branched
LEAVES :
The leaves are dimorphic.
The foliage leaves are simple, needle like or pinnately
compound
Scale leaves are small, membranous and brown.
GYMNOSPERMS
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17. The gymnosperms are heterosporous; they
produce haploid microspores and megaspores.
The two kinds of spores are produced within
sporangia that are borne on leafy structures
called sporophylls which are arranged spirally
along an axis to form lax or compact strobili or
cones.
The strobili bearing microsporophylls and
microsporangia are called male strobili or male
cone
The microspores develop into a male
gametophytic generation which is reduced and
is confined to only a limited number of cells.
This reduced gametophyte is called a pollen
grain. The development of pollen grains take
place within the microsporangia.
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18. The cones bearing megasporophylls
with ovules are called female strobili or
female cone
The male or female strobili may be
borne on the same tree (Pinus).
However in Cycas, male cones and
megasporophylls are borne on different
trees. The megaspore mother cell is
differentiated from one of the cells of
the nucellus (nutritive tissue of the
ovule).

19. GYMNOSPERMS HETEROMORPHIC ALTERNATION OF GENERATION
SPOROPHYTE
Diploid
Dominant
Independent
GAMETOPHYTE
Haploid
Recessive
Dependent
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20. 1. Timber Production: Gymnosperms are valued for their wood, which is used in construction, furniture
making, paper production, and other industries. Species like pine, spruce, fir, and cedar are particularly
prized for their timber.
2. Pulp and Paper Industry: Coniferous trees are a major source of wood pulp used in paper and cardboard
production. Their long fibers make them well-suited for producing high-quality paper products.
3. Resin and Turpentine: Some gymnosperms, such as pine trees, produce resin and turpentine, which are
used in the production of varnishes, adhesives, solvents, and other industrial products.
4. Medicinal Uses: Certain gymnosperms have medicinal properties and are used in traditional medicine
systems. For example, extracts from the bark of some conifer species are used to treat coughs, colds, and
respiratory ailments.
5. Ornamental Plants: Many gymnosperms, such as pine, spruce, and juniper, are cultivated for ornamental
purposes in gardens, parks, and landscapes. Their evergreen foliage and unique forms add aesthetic value to
landscapes.
6. Food Source: The seeds of some gymnosperms, such as pine nuts (from pine trees) and ginkgo nuts (from
ginkgo trees), are edible and used in cooking and culinary applications.
7. Soil Stabilization: The extensive root systems of some gymnosperms help stabilize soils, prevent erosion, and
improve soil structure, particularly in mountainous and windy regions.
Economic Importance of Gymnosperms

21. ANGIOSPERMS
Most advanced division of the flowering plants
The plant body is differentiated into
root, stem and leaves.
It has flowers, fruits and seeds.
Vascular tissues are well developed.
Xylem shows vessels or tracheae while
phloem has sieve tubes and companion cells.
Highly evolved plants, primarily adapted to
terrestrial habitat.
Wolffia is the smallest angiosperm, l mm in size and
Eucalyptusgrows to over 100 meters.
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22. ANGIOSPERMS HETEROMORPHIC ALTERNATION OF GENERATION
Diploid
Autotrophic
Dominant
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Haploid
Dependant
Recessive

23. 1. Food Production: Angiosperms provide the majority of the world's food supply. Crops such as wheat, rice,
maize, soybeans, and potatoes are all angiosperms. Fruits, vegetables, nuts, and oils derived from flowering
plants are essential components of human diets worldwide.
2. Cash Crops: Many angiosperm species are cultivated as cash crops for their economic value. These include
crops like cotton (for fiber), coffee, tea, cocoa (for beverages), sugarcane (for sugar), and tobacco (for
cigarettes).
3. Ornamental Plants: Angiosperms are widely cultivated for their aesthetic appeal in gardens, parks, and
landscaping. Flowering plants such as roses, orchids, tulips, and lilies are highly valued for their beauty and
are used in floral arrangements, bouquets, and decorative purposes.
4. Medicinal Plants: Numerous angiosperms have medicinal properties and are used in traditional medicine
systems as well as modern pharmaceuticals. Examples include plants like aspirin (from willow bark), quinine
(from cinchona bark), and morphine (from opium poppy).
5. Timber and Wood Products: Many angiosperm species are harvested for timber, plywood, and other wood
products. Hardwoods like oak, maple, mahogany, and teak are prized for their strength, durability, and
aesthetic qualities in furniture making, construction, and woodworking industries.
Economic Importance of Angiosperms

24. 6. Biofuels and Renewable Resources: Some angiosperms are cultivated for biofuel production, including
ethanol derived from sugarcane, corn, and other crops. Additionally, plants like switchgrass and jatropha
are being explored as sources of biofuels for transportation and energy generation.
7. Textile Industry: Fibers derived from angiosperms, such as cotton, linen (from flax), jute, and hemp, are used
in the textile industry for making clothing, fabrics, ropes, and other textiles.
8. Land Reclamation and Soil Conservation: Angiosperms play a crucial role in land reclamation and soil
conservation efforts. They help stabilize soils, prevent erosion, and restore degraded landscapes through
their extensive root systems and canopy cover.
9. Pollination Services: Many angiosperms rely on pollinators like bees, butterflies, and birds for reproduction.
They provide ecosystem services by supporting pollinator populations and maintaining biodiversity, which in
turn benefits agriculture and food production through pollination.
Economic Importance of Angiosperms