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CHARACTERISTICS OF PLANTS.
Plants are living organisms of the kingdom Plantae; which includes multicellular groups
such as thalophytes, an example is spirogyra, bryophytes an example is moss, pteridophytes
an example is fern, gymnosperms an example is pinus and angiosperms an example is bauhinia
acuminata. One of the striking features of plants is that they characteristically obtain
most of their energy from sunlight through the process known as photosynthesis. Plants
use chlorophyll to capture light energy from the sun, which produces foodósugar, starch,
and other carbohydrates. To do our experiment we will require the following
plants. Spirogyra, Agaricus, Moss, Fern, Pinus and
an Angiosperm plant.
Let us now study the characteristics of the different pants.
CHARACTERISTIC OF SPIROGYRA
Spirogyra comes under the group chlorophyta and commonly occurs in fresh water bodies
such as ditches, ponds, lakes, etc. Spirogyra is commonly called water silk because
it has a silky appearance. It is filamentous green algae with more than
500 species in the world. Each filament is unbranched and consists of
cylindrical cells placed end to end. Each cell has one or more beautiful spiral
chloroplast which gives it a dark green appearance. Cytoplasm lies in the periphery of the cell
enclosing a vacuole in the centre. Identifying Features of the Group
They have a thaloid body, which means the body is not differentiated into root, stem
and leaf. The plant cell contains chlorophyll and other
pigments. They are autotroph and predominantly aquatic.
CHARACTERISTIC OF AGARICUS
Agaricus is a fleshy saprophytic fungus containing both edible and poisonous species with over
300 varieties. It is normally found during wet and damp climates.
It grows on wood and in humus-rich soil. The upper visible part above the ground is
called basidiocarp. The members of Agaricus having a fleshy cap
called pileus. From the underside of Agaricus grows a number
of radiating plates called gills or lamellae. The gills bear club shaped basidia on either
side and it carries basidiospores. Identifying Features of the Group
Agaricus does not possess the pigment chlorophyll. It is a saprophytic in nutrition.
CHARACTERISTIC OF MOSS
Moss is a Bryophyte which grow on moist brick walls, and as thick mats on forest floors.
It is green, erect and is differentiated in to rhizoids, axis and leaves.
Rhizoids are multicellular which helps to anchor the plants.
The main axis bears antheridia at its apex. A lateral branch called female shoot bears
archegonia at its tip. After fertilization a particularly dependent
sporophyte develops on the female shoot. The sporophyte is differentiated into foot,
seta and capsule. The capsule encloses the spore sac that produces
spores. Identifying Features of the Group
The plant body is green, leafy and bears rhizoids. It is a non-flowering autotroph plant.
It is found on moist, shady and damp soil. It does not bear specialized conducting tissues.
CHARACTERISTICS OF FERN
Ferns belong to the lower vascular plant division Pteridophyta and are found in humid and shady
places. The plant body is well differentiated into
root, stem and leaves. The young leaves usually unroll from a tight
fiddle head or circinate leaf. The leaflets are small and arranged on either
side of the rachis. It does not produce seeds or flowers but reproduces
through spores. The stem is mostly an underground creeping
rhizome. Clusters of adventitious roots arise from
the underside of the stem near each node. The gametophyte in the plant is reduced to
a small kidney-shaped prothallus, which contains Antheridia and Archegonia.
Identifying Features Ferns are vascular plants having xylem and
phloem for the conduction of food and water. They have stem, leaves and roots.
The adult plant is sporophytic dominant.
CHARACTERISTIC OF PINUS
The pinus is a Gymnosperm which is an evergreen tall tree differentiated in to root, stem
and leaves. The stem of the tree is covered with bark.
The vascular system is well developed. A pinus tree is monoecious and bears both
male and female cones. It produces naked seeds, which means that
the seeds are not enclosed in fruit. Male cone
Male cones are borne in clusters on long branches. The male cone consists of numerous spore bearing
leaves, the microsporophylls, arranged spirally on the central axis.
A mature cone is dark brown in colour. Each microsporophyll has a stalk, broad lamina
and tip curved upwards to fit over the microsporophyll above it. It bears two sporangia on its lower
surface. The sporangia are filled with numerous winged
microspores, the haploid male gametophyte. Female cone
Female cones are borne singly on the long branches and mature cones are brown in colour.
It contains bract scales that are arranged spirally on the central axis.
In the axils of each bract scale an ovuliferous scale is present, called the microsporophyll.
It bears two ovules on the upper surface and each of the ovule has integument nucellus
and female gametophyte. Identifying Features
The seeds are naked. The reproductive organs are cones.
Well developed xylem and phloem tissues are present.
CHARACTERISTIC OF ANANGIOSPERMIC PLANT (Bauhinia acuminata)
Bauhinia acuminata is a species of an angiosperm plant native to tropical southeastern Asia.
The plant body is differentiated in to root, stem and leaves.
Like the other Bauhinia species, the leaves are bilobed, shaped like an ox hoof.
The leaves are sessile and have a reticulate venation.
It bears flowers that are reproductive organs. The flower has five petals so pentamerous.
The roots are tap root having number of root hairs.
It produces seeds that are enclosed within the fruit.
Identifying Features
Angiosperms are vascular plants. They bear flowers which are the reproductive
organs of the plants. The seeds are covered as they are enclosed
inside the fruit.