Transcript Kingdom Plantae

Kingdom Plantae
General Characteristics
• Use photosynthesis to
gain energy, therefore
autotrophic.
• Live in all aquatic and
terrestrial habitats except
at the poles.
• Are the main source of
oxygen for the planet
• The basis for every food
chain or food web
Classification of Plantae
• Although there are a
vast variety of plants
in the world, they can
all be placed in one of
four main groups.
• Each large group
contains several
divisions, which are
the rough equivalent
to a Phylum.
1) Non-Vascular Plants (Mosses
and their relatives)
• Three divisions (mosses,
hornworts and liverworts).
• No vascular tissue, therefore
depend on osmosis and
diffusion to transport nutrients.
• Usually grow in dense mats of
low tangled vegetation that can
hold water like a sponge,
allowing them to survive cold
or dry periods.
• Have no roots, instead have
root-like rhizomes.
• Sexual reproduction.
Non-vascular Plants
Mosses (Bryophytes)
•
Very successful and widespread as
they thrive in such diverse habitats
as bogs, tundra, on bare exposed
rocks, and in deep shade.
•
Twice as many species of mosses
as there are mammals!
Liverworts (Hepatophytes)
•
Grow flat, low to the ground and are
rarely more than 30 cells thick.
•
80% are leafy and live in tropical
forests and in humid climates.
•
Thallose liverworts are the other
20%.
•
Many small chloroplasts per cell.
Hornworts (Anthocerophytes)
•
Broad, flat and are commonly bluegreen in colour.
•
One large chloroplast per cell
2) Seedless Vascular Plants (Ferns
and their relatives)
• came about 300 million years ago
• developed the vascular tissue that allowed them
to grow tall
Seedless Vascular Plants
Whisk Ferns (Psilotophytes)
• Look like small green whisk
brooms
• No leaves or roots
• Short rhizomes, which are
horizontal, underground stems.
• Produce spores.
Club Mosses (Lycopodophytes)
• Small evergreen-looking plants
that grow in dense mats in
moist temperate or tropical
forests.
• Not related to true mosses!
• Have true roots and stems.
Seedless Vascular Plants
Horsetails (Sphenophytes)
•
Once included tree-sized members, but
now just smaller plants (1 m).
•
Often found in damp areas or along
roadsides.
•
Can be used to scour pots.
•
Have silica in their cells, which accounts
for the roughness.
•
Can be made into a shampoo to combat
head lice.
Ferns (Pteridophytes)
•
Dominated the forests during the
Carboniferous period (315-280 mya).
•
Most familiar and successful of the
seedless vascular plants.
•
Have roots, stems, a waxy epidermis that
reduces water loss by evaporation and
stomata in their leaves for gas exchange.
•
Ferns produce millions or even billions of
spores in their lifetime.
•
Have fronds, which are seed leaves that
grow up from rhizomes.
3) Gymnosperms (Conifers and
their relatives)
• disperse by means of seeds
• reproduce sexually without
needing water
• have seeds that are exposed
on the surface of cone scales
• gymnosperm means ‘naked
seed’
• includes cone-bearing trees:
pines, firs, spruce, yew,
cedars, redwood and many
other large trees.
• Also includes the
cycadophytes, gnetophytes
and ginkgophytes.
Gymnosperms
Conifers
•
Form vast forests in the colder
regions of the world
•
As well as reproducing without
water, they have bark to prevent
water loss.
•
The pyramidal shape of many
conifers helps snow and ice slide off
the tree reducing branch breakings.
•
The needle like leaves have a thick,
waxy cuticle and sunken stomata,
which reduce the rate of
evaporation.
•
These are evergreens, which are
continually losing and replacing
needles all year round.
Gnetophyta
•
Very rare, found in southern Africa
Gymnosperms
Cycadophyta
•
100 species in the tropics,
once dominated the earth.
•
Short, palm-like trees with
scaly trunks.
Ginkgophyta
•
The only living species is
Ginko biloba, which was
common during the Jurassic
period (200 mya).
•
Cultivated in Asian temples
for hundreds of years, which
helped protect against
extinction.
4) Angiosperms (Flowering Plants)
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Plants that protect their seeds
within the body of a fruit are called
angiosperms or flowering plants.
Appeared on earth more than 150
mya.
Include vines, grasses, shrubs,
trees and water plants.
Grow everywhere on land from
tundra to tropics.
Divided into monocots (1 seed
leaf) and dicots (2 seed leaves)
Sexual reproduction by pollination.
Use wind, water, animals, bats,
birds and insects as pollen
carriers.