Classification of plants - Varga

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Three Types of Plants That We
Will Discuss...

Seedless, non-vascular plants

Seedless, vascular plants

Seed-bearing plants – all of them are
vascular.
Seedless,
Non-vascular Plants
Also known as BRYOPHYTES
Bryophytes (non-vascular)

Bryophytes are non-vascular plants, which
means that they do not have xylem and
phloem.

Because they do not have a vascular system,
bryophytes require an external source of water
in order to survive, such as dew or rain.

Bryophytes usually grow in damp, dark
environments to provide and retain moisture.
MOSS is an
example of a
bryophyte
Despite the fact that they
require an external source
of water, bryophytes can
often grow where other
organisms can not, such as
the harsh desert. They do
this by entering a state of
dormancy until a water
source is available.
This ability of mosses makes them critical in colonizing dry, inhabitable lands
and beginning the soil-making process.
Properties of Mosses

Mosses do not have true leaves. They have
structures that look like leaves, but they are
only one cell thick.

Some mosses have cuticles, and most of
them have stomata.

Mosses anchor themselves to surfaces using
rhizoids.
Make Some Assumptions About
Bryophytes for These Questions...

How tall do you think a bryophyte can
grow, and why do you think this?

What are some challenges that bryophytes
might have reproducing?

If you were a plant, do you think you
would want to be a bryophyte? Why or
why not?
Seedless,
Vascular Plants
Club Mosses and Ferns are seedless,
vascular plants.
A TYPE OF FERN
CLUB MOSS
Seedless, Vascular Plants

Club mosses, which are not true mosses,
belong to the oldest living group of vascular
plants.

300 million years ago, shallow swamps were
home to enormous seedless, vascular
plants, which got wiped out. Their remains,
however, got pressed and heated
underground, forming coal. This is why coal
is called a FOSSIL FUEL.
Club Mosses and Ferns

Some club mosses look like mini pine trees,
and are sometimes called “ground pines.”

Ferns are the most successful survivors of the
carboniferous period, with about 12,000
currently living species that existed back then.

Some tree ferns can grow over three stories
tall.
Make Some Assumptions About
Bryophytes for These Questions...

Why can club mosses and ferns grow taller
than a bryophyte?

Although they are able to grow taller, club
mosses and ferns still have some evolutionary
disadvantages. What are they?

Would you rather be a seedless, vascular plant
or a bryophyte? Why or why not?
Seed-bearing,
Vascular Plants
These include Flowering Plants!
Seed Plants Have 3 HUGE
Evolutionary Advantages...
1. Seed plants can reproduce
without free-standing water.
-
-
Unlike the seedless plants, seed plants do
not depend on water to transport their
sperm to the eggs.
Seed plants produce pollen. Pollination
occurs when pollen meets female
reproductive parts of the same plant
species.
Seed Plants Have 3 HUGE
Evolutionary Advantages...
2. Seeds nourish and protect plant
embryos
-
-
-
Remember that a seed is a protective outer
layer that contains a food source and a plant
embryo.
Seeds can survive for many months or years in
a dormant state, and they can survive harsh
conditions that would kill an adult plant.
The plant embryo will begin to grow when
conditions are favourable for the plant.
Seed Plants Have 3 HUGE
Evolutionary Advantages...
3. Seeds allow plants to disperse to
new places
-
-
Wind, water, or animals can carry seeds to
new places far from where the individual plant
produced them.
Many seed plants have dispersal mechanisms,
such as “wings” for their seeds.
It is thought that seed plants may have
evolved when earth’s climate shifted from
warm and moist to hot and dry.
Seed Plants Can Be Grouped Into
Two Categories
Gymnosperm
•
•
Angiosperm
A seed plant whose
seeds are not
enclosed in a fruit.
•
A seed plant that has
seeds enclosed in
some type of fruit
Most are cone-bearing
and evergreen
•
Angiosperms belong
to a phylum of their
own, and are called
flowering plants.
Flowering Plants

A flower is the reproductive structure of a
flowering plant.

Flowers protect a plant’s gametes and
fertilized eggs, the way woody cones do for
gymnosperms.

A fruit is the mature ovary of a flower, and
contains the seeds of the plant.
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