Gymnosperms
Group 3: Seed producing, Vascular Plants
• Gymnosperms
– Cycads
– Ginko
– Conifers
• Angiosperms
Seeds and their advantages
• 1) Seed plants don’t
depend on water to
reproduce
– Pollen (contains sperm)
carried by wind/animals
– Zygote hardens into a
seed
• 2) Embryo has…
– Nourishment: Nutrients
inside feed embryo
– Protection: Hard shell
• 3) Allow dispersal
– Carried by wind, water,
animals
Some seeds are
“dispersed”
by “wings”
animals
Some
seeds have
Seeds and their advantages
• 1) Seed plants don’t
depend on water to
reproduce
– Pollen (contains sperm)
carried by wind/animals
– Zygote hardens into a
seed
• 2) Embryo has…
– Nourishishment:
Nutrients inside feed
embryo
– Protection: Hard shell
• 3) Allow dispersal
– Carried by wind, water,
animals
Seeds and their advantages
• 1) Seed plants don’t
depend on water to
reproduce
– Pollen (contains sperm)
carried by wind/animals
– Zygote hardens into a
seed
• 2) Embryo has…
– Nourishishment:
Nutrients inside feed
embryo
– Protection: Hard shell
• 3) Allow dispersal
– Carried by wind, water,
animals
Group 3: Seed producing, Vascular Plants
• Type 1: Gymnosperms
• Needle-like leaves (reduces
water loss)
• Common to lumber industry
• Seeds enclosed in cones
– Male cones: produce
pollen (pollen cone)
– Female cones: produce
eggs (seed cone)
• Zygote hardens into seed
(protected inside cones)
• Ex: Evergreen, Pine,
Redwood, Cedar
Conifer Life
Cycle
.
Z
e
• Sporophyte phase (dominant)
– Cones grow on tree
– Male cones
• Spores created by meiosis &
released
• Spores develop into pollen
– Female cones
• Spores created by meiosis
• Male pollen lands on female
cone
• Pollen tube grows towards
egg
• Sperm travels down pollen
tube
• Spore hardens into seed
• Seed released & grows into
new sporophyte
Conifer Life
Cycle
• Sporophyte phase (dominant)
– Cones grow on tree
– Male cones
• Spores created by meiosis &
released
• Spores develop into pollen
– Female cones
• Spores created by meiosis
– Egg forms inside spore
• Male pollen lands on female
cone
• Pollen tube grows towards
egg
• Sperm travels down pollen
tube
• Spore hardens into seed
• Seed released & grows into
new sporophyte
1) Male and female seed cones grow on adult sporophytes
2) Pollen grains released from the male seed cones
-- Pollen is the male gametophyte
Let’s zoom into the female seed cone…
3) Pollen grain sticks to the female ovule
4) Pollen tube grows from the male spore
5) Two sperm travel into female spore
- one fertilizes the egg
6) Diploid embryo develops inside female cone (sporophyte stage restarts)
7) After seeds harden, the cone reopens and
the seeds are released
8) Seed will land
Ground
9) Seedling grows into (sporophyte)…the cycle repeats
Ground
female
male
Plant Life Cycle Comparisons
`
Sporophyte
Gametophyte
Dominant?
Moss
Stalk with cup at tip,
which is where spores are
produced.
More familiar, carpetlike plant that
produces specialized
gametes
XX - Archegonium
XY - Antheridium
GAMETOPHYTE
Fern
More familiar, leafy plant
with clusters of spore
producing sacs (sori)
Haploid plant body
(prothallus) is size of a
finger nail, produces
both male and female
parts
SPOROPHYTE
Conifer
(Gymnosperm)
More familiar- like pine
trees, produces male and
female cones that
produce spores
Male gametophytes
are pollen grains
sperm
Female gametophytes
are microscopic
eggs
SPOROPHYTE
Review
1) Name three advantages of seeds.
2) Which structure will protect gymnosperm
seeds?
3) What do male cones produce?
4) What do female cones produce?
5) What is created when the sperm and egg fuse:
sporophyte or gametophyte?