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PLANTS
By Laura Molina
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Everywhere you see, you see a
green cover, with different types
of plants and trees. Plants and
plant products are something very
familiar that you use in your
everyday life. But, have you ever
wondered about the different
types of plants and trees? Did you
know that the Plant Kingdom is
divided into several subgroups,
with each one having special
features? Delve into the depths
of Kingdom Plantae and unearth
some of the fascinating facts.
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These living organisms are
made of eukaryotic cells and
are multicellular. The cells
have a cell wall which is made
of cellulose. These
are autotrophic and
synthesize food
by photosynthesis due to the
presence of chloroplasts.
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EUKARYOTIC
CELLS
Eukaryotic cells are cells that
contain a nucleus and
organelles, and are enclosed
by a plasma membrane.
Organisms that
have eukaryotic cells include
protozoa, fungi, plants and
animals.
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MULTICELLULAR
All species of animals, land
plants and most fungi are
multicellular, as are many algae,
whereas a few organisms are
partially uni- and partially
multicellular, like slime
molds and social amoebae such
as the genus Dictyostelium.
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CELL WALL
A cell wall is a structural layer
surrounding some types
of cells, just outside the cell
membrane. It can be tough,
flexible, and sometimes rigid.
It provides the cell with both
structural support and
protection, and also acts as a
filtering mechanism.
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CELLULOSE
Cellulose is an organic compound
with the formula, a polysaccharide
consisting of a linear chain of
several hundred to many thousands
of linked D-glucose units.Cellulose
is an important structural
component of the primary cell wall
of green plants, many forms of
algae and the oomycetes. Some
species of bacteria secrete it to
form biofilms.
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AUTOTROPHIC
An organism capable of synth
esizing its own food from inor
ganic substances, using light o
r chemical energy. Green plant
s, algae, and certain bacteria a
re autotrophs.
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PHOTOSYNTHESIS
Photosynthesis is a chemical
reaction that takes place
inside a plant, producing food
for the plant to survive.
Carbon dioxide, water and
light are all needed
for photosynthesis to take
place. Photosynthesis happens
in the leaves of a plant.
zBased on whether plants have
a well-differentiated body and
the presence or absence of
specialized tissues for
transport, and the ability to
bear seeds Kingdom Plantae
(Plant Kingdom) is can be
classified into different
divisions. The features and
examples of each division are
mentioned hereunder.
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DIVISION
THALLOPHYA
These are the lowermost plants
of the plant kingdom, without a
well-differentiated body design.
This means that the plant body
is not differentiated
as roots, stem, and leaves. They
are commonly called algae, are
permanently aquatic. Examples
include Spirogyra, Chara, and
Ulothrix.
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DIVISION OF
BRYOPHYTYPES
Bryophytes are an informal
group consisting of
three divisions of non-vascular
land plants (embryophytes):
the liverworts, hornworts and m
osses.[1] They are
characteristically limited in size
and prefer moist habitats
although they can survive in
drier environments.[2] The
bryophytes consist of about
20,000 plant species.
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PTERIDOPHYTE
DIVISION
A pteridophyte is a vascular
plant (with xylem and phloem) that
disperses spores. Because
pteridophytes produce
neither flowers nor seeds, they are
sometimes referred to as
"cryptogams", meaning that their
means of reproduction is
hidden. Ferns, horsetails (often
treated as ferns),
and lycophytes (clubmosses, spikem
osses, and quillworts) are all
pteridophytes.
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DIVISION
PHANEROGAMAE
Phanerogams are seed-bearing
plants. The plant body is well
differentiated with stem, leaves,
and roots. There are well
differentiated reproductive tissues
that produce seeds. These plants
also have a well-developed vascular
system. Depending on whether the
seeds produced are naked or
whether they are enclosed,
phanerogams are further classified
into two subdivisions. They
are Gymnosperms and Angiosperms.
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GYMNOSPERMS
Gymnosperms are plants with
naked seeds. There are about
650 living species of
gymnosperm plants. The plants
are usually perineal, evergreen
and woody. They have a welldeveloped vascular tissue but
do not have vessels. The
reproductive organs generally
form cones or strobilus. There
is no fruit formation and the
seeds are hence said to be
naked. Examples: Cycas, Pinus,
Deodar.
ANGIOSPERMS
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Angiosperms are seed-bearing plants. Seeds
develop inside tissues that get modified to
form the fruit of the plant. Also called
the flowering plants, they are found
abundantly in nature. These plants are
usually terrestrial and they may be annual,
biennial or perennial. The vascular system is
very well developed with xylem and phloem.
Angiosperms also show the feature of
double fertilization. Examples: Mustard
plant, Pea plant. On the basis of the
cotyledons (seed leaves) Angiosperms are
further divided into Monocotyledonous
plants and Dicotyledonous plants.
Monocots have seeds with single seed leaf,
having vascular bundles arranged in a
complex manner. Dicots, on the other
hand, have two cotyledons. The vascular
bundle is arranged in a ring.