2. Divisions
The plant Kingdom is divided into
Divisions rather than Phyla
We only need to know about:
The Ferns and
Angiosperms (flowering plants)
3. Mosses (for interest only)
Mosses are small plants that only grow in
damp areas because they do not have a
cuticle to stop them drying out
They so not have proper leaves, stems or
roots
4. Ferns (Pteridophytes)–
you need to know about these
These plants
dominated the
world when
dinosaurs were
around but are
not so common
now
5. They have a cuticle so
can grow in dryer
areas
They have true roots
and stems with xylem
and phloem to
transport water and
sugars
They spread using
rhizomes that grow
away from the parent
plant
6. The leaves are called fronds
These grow by unfurling from
fiddleheads
11. Spores are made in these by cell
division called meiosis
This gives the spores half the number
of chromosomes or n
12. Spores are released and
blown by the wind
When they land in soil
they can grow into a tiny
microscopic pant called a
prothallus
This has only half a set
of chromosomes
13. The prothallus is also called a
gemetophyte because it
makes gametes (sex cells)
These are made by mitosis so
they have half a set of
chromosomes
These are like roots
This is a leaf-like structure
but is very small
14. The male and female
sex cells fuse
to form a new plant
with a full set of
chromosomes
It grows out of the
gametophyte
16. Because they are pretty ferns are
popular house and garden plants
17. Gymnosperms (for interest only)
These are plants that
reproduce using cones – like
Pine Trees
The forests in North America
and Europe are mostly
coniferous
They have “soft wood” and
grow quickly so are grown for
paper and furniture
18. Angiosperms – flowering
Plants
you need to know this group
Most of the plants we see are angiosperms
They reproduce using flowers (sometimes
the flowers are so small we can’t see them)
The plants may be trees, shrubs, grasses, or
herbs
All of our important crops are angiosperms
19. There are two main groups:
Monocotyledons and Dicotyledons
The names of theses groups comes form the
number of cotyledons in the seeds
The Cotyledon is a food storage area:
Dicotyledons have 2 and Monocotyledons have
one
Use this information to start filling in the table on
20. In fact these days scientists divide
the groups by what the pollen looks
like
Monocotyledons have one furrow,
Dicotyledons have two or more
These pollen grains have been highly magnified
by a scanning electron microscope
21. Roots
Monocotyledon roots are fibrous – they
branch out just below the soil
This makes plants like grasses useful for holding soil in
place and preventing erosion
Dicotyledons tend to have tap roots – this is a
long main root with side (lateral) roots
coming off it
Dicotyledon roots can go deep into the soil to find
water
22. The next slide has some simple drawings
for you to copy
If we look at the roots in
cross section we will see:
Monocotyledons have a ring
of xylem and phloem and a
central pith – this is packing
cells or a hollow region
Dicotyledons have the xylem
and phloem in the middle
We will learn how xylem
carries water and phloem
carries sugar later this year
24. Stems
Vascular bundles
monocot
Dicot
Xylem and phloem are grouped together in
stems to form vascular bundles
In Monocotyledons the vascular bundles are
scattered around
In Dicotyledons they are neatly set in a ring
near the edge
26. leaves
monocotyledon
dicotyledon
petiole
One of the easiest ways to tell Monocotyledons from
Dicotyledons is by the veins in their leaves. Veins are
made of the xylem and phloem
In Monocotyledons the veins are parallel and there is
no petiole (stem)
In Dicotyledons the veins are net-like and they have a
petiole
Can you work
out the
magnification
of these
leaves using
the scale bar?
27. Flowers
We will learn about flowers next year
For now be aware that the flower parts (petals, anthers)
come in 3’s in Monocotyledons, and in 4’s or usually
5’s in Dicotyledons
Most monocotyledons are grasses and are wind pollinated
so the flowers are really small and not brightly coloured
28. Check you have filled in the
table completely in your
notes
