Plant Growth and Development
Seeds
Flowers
Fruits
Seeds Start it All
• Seed contain embryos
that form into new
plants.
• Seeds can stay
dormant for 1000’s of
yrs.
• Favorable conditions
or damage to a seed
coat start growth
Some seeds
•
•
•
•
Need light exposure
Soil moisture
Perfect temperature
Or any environmental
change that can spark
rapid growth.
• Damage to seed coat
through….
– Fire
– Passing through the
digestive tract of
animals
– Falling on a rock
– Once the damage is
done the seed must fill
up with enough water
and oxygen to grow
Monocot seed growth vs. dicot
Seed Parts
•
Seed parts continued
• Monocot– Seed coat for
protection
– Radicle is the
embryonic root
– Plumule is the
embryonic leaf
– Endospermis nutrition
– 1 cotyledon (seed leaf)
• Dicot
–
–
–
–
–
Seed coat (protect)
Radicle (root)
Hypocotyl (stem)
Epicotyl (leaf)
2 cotyledons (seed
leaves for primary
nutrients to embryo)
– Endosperm matured
into cotyledons
Fertilization of seedless plants
• Zygote develops into
sporophyte
• Spores develop into
gametophytes
• Antheridia (male)
• Archegonia (female)
• Male swim to female
• Zygote is formed
Fertilization of Gymnosperms
• Immature seed cone
(female)
• Pollen cone (male)
• Gametophytes
• Female + male =
zygote
• Pine seed with wing is
the zygote
(sporophyte)
Fertilization of Angiosperms
• Pollen (male) from
the anther
(gametophyte)
• Ovule (female) from
the ovary
(gametophyte)
• Pollination = zygote
• Zygote = seed
• Flower becomes a
fruit.
Flower parts
• Petals attract pollinators
• Sepal protects the flower
• Stamen is the male
reproductive organ
• Filament holds anther
which contains pollen
• Pistil is female organ that
has stigma to catch pollen
to send down pollen tube
to ovary (ovule)
Growing without seeds
• It’s called vegetative reproduction and
occurs with roots stems or leaves.
• Helps allow plants to cover areas faster
• 100’s and 1000’s from one single plant
• Examples include: runners (bermuda
grass), bulb (onion or tulip), Corm
(gladiolus), Rhizome (Fern), Tuber
(potato)
Runner
• Horizontal above
ground stem that
helps the plant spread
within an area.
Bulb
• Very short stem with
thick fleshy leaves
Corm
• Very short thick
underground stem
with thin scaly leaves
Rhizome
• Horizontal
underground stem
Tuber
• Swollen fleshy
underground stem