Transcript Seeds and their advantages

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…
– Nourishishment:
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 sone)
• Zygote hardens into seed
(protected inside cones)
• Ex: Evergreen, Pine,
Redwood, Cedar
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
Z
e
• 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
female
male