Transcript Gymnosperms

Biology 11
KINGDOM PLANTAE
Vascular Plants
Phylum Tracheophyta
Seeds
Seeds
enclosed
No Seeds
Seeds
‘naked’
Ferns
Phylum
Cycadophyta (cycads)
Ginkgophyta (ginkgo)
Gnetophyta (shrubs, vines,
tuberous root)
Coniferophyta (cone-bearing tree)
 Protective
covering around embryo
(seed)
 Produce cones with seeds on cone
scales
 Seed develops on each scale of cone
 Seed is not covered therefore naked
 Gymnosperms:
 Seeds
(ovary)
“naked seed”
are not enclosed by a fruit
Reproduction
occurs without water
Improved conducting tissue: thicker
and stronger xylem. Became taller
Large, branching root system
 Gametophytes
are reduced in size,
often staying within the parent
sporophyte
 Swimming sperm are replaced with
pollen which is dispersed by wind
and insects
 Produce seeds
Seed Plants
Vascular
 Resemble
palm trees but are cone bearing
 Have fleshy stems and leathery, featherlike
leaves
 Motile sperm that swim to egg in ovule
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Primitive tree
Dioecious: has separate male
and female trees
Leaves are fan shaped and
thick with leathery veins
Have motile sperm that swim to
the egg in the ovule
 Can
be found as shrubs, vines, or massive squat
stems
 Have sperm with no flagella

Pollen is transported to ovule (egg) by insects or wind
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Conifers – cone bearers (separate male
and female cones)
Many are evergreen and keep their
leaves in the winter
Can grow very large and to old ages
•
Are adapted to severe climates and conserving
water with leaves, called needles, that are
covered with waxy cuticles and are long, sharp,
and tend to be flat
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Have sperm with no flagella
•
Pollen is transported to ovule (egg) by insects or wind
 There
are 2 types of cones:
 Male
cone (Pollen cone)
 Produces pollen grains (male
gametophyte)
 Female
cone (Seed cone)
 Have female gametophyte
that produces ovules (eggs)
Some
species of
conifers have
male and female
cones on the
same tree,
others have
separate trees
with male and
female cones
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A female cone lives and grows for
several years, becoming much
larger than a male cone.
An ovule develops on each scale of
a female cone.
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Inside the ovule, an egg cell is
produced.
Male cones produce pollen (male
gametophyte)
MALE CONES (with pollen)
FEMALE CONE
With ovules
If fertilization occurs, an embryo grows
inside the ovule. The ovule hardens,
becoming a seed.
• Eventually the scales spread, allowing the
seeds to fall.
• If conditions are favourable where it falls,
the embryo inside the pine seed will grow
into a new tree.
• Growing
Sporophyte called
A seedling
•
Alternation
of
generations