Download Plant_powerpoint - District 128 Moodle

What is a plant?
• Multicellular
• Autotroph
• Sounds like it could be a protist so far.
• And the embryo develops within the
mother plant.
• Plants evolved from green algae
Flower Parts
• Pollen (male sperm) lands on the
female stigma
• Pollen travels down to the ovary
and fertilizes the ovules (egg)
• Develops into a seed
What happens when a flower
dies?
• When a ovule becomes fertilized, the flower is
no longer needed.
• The petals fall off, and the seed needs some
protection.
• The ovary forms into a fleshy body to protect
the seed.
• A fruit is an ovary that has enlarged to protect
a seed!
Seeds can be protected in different
ways.
• When plants bear seeds that are ‘naked’,
meaning not enclosed in an ovary they are
called a______________.
• When seeds are protected in a fruit, they
are classified as a/n _____________.
Do grasses have fruits?
• Grasses have fruits!
• Corn
• Rice
• Wheat
Seed Anatomy
See board for more info
Seed Dispersal
• Seeds have adapted so make it easier for
them to land in different places and
eventually grow into a new plant.
• Stick to animals ( Burrs)
• Edible fruits (fruits)
• Travel by wind or water (helicopters/maple
seeds, dandelions)
Seed Germination
• When a plant begins to grow, it
needs favorable conditions.
• They must soak up water!!
• By taking up water, the seed
expands and splits its seed coat.
Asexual Reproduction
• Remember cloning???
• Asexual reproduction in plants is called
vegetative reproduction.
• Many plants drop stems or shoots that
develop into new plants (same DNA), and
strawberries send out runners.
Anybody like to have beautiful flowers
but not want to have to plant them
year after year?
• Annuals – complete their life cycle
(germinate, grow, produce flowers and seeds,
and die) in one year.
• Biennials complete the cycle in two years and
flower the second year.
• Perennials live and reproduce for many years.
• Which type of flower would you plant and
why?
Plant structure
•
•
•
•
Buds – undeveloped shoots
(terminal =end of a stem)
Blade – main part of the leaf
Petiole – connects leaf to the
stem
• Leaf veins – carry nutrients
to/from leaves
Root types
• Fibrous roots – a mat of thin roots spread out below
the surface providing increased exposure to
nutrients and water
• Tap roots – characterized by one large vertical root
with many smaller branches
ex. carrots, turnips, and beets
Stems – support and transportation
• Vascular tissue – tubular cells used for
transporting materials (like human
veins)
• Two Types –
– Xylem – transports water and dissolved
minerals upward from roots into the
shoots
– Phloem – transports food (glucose) made
in the leaves down to the parts that don’t
make their own food (roots)
Plant Growth
When a plant grows in
length, this is called
primary growth.
Meristems – tissues that
have cells going
through mitosis
Where is growth
occurring?
What protects the root?
-Root cap
If primary growth is growth in
length, what is secondary growth?
• Secondary growth is growth in width
• Occurs in woody plants
• Vascular cambium (actively going through
mitosis) adds cells resulting in secondary growth
•
•
secondary xylem – wood
everything outside the vascular
cambium is bark (made up of
cork)
What are tree rings?
• Each year, the plant grows new vascular
cambium cells.
• In the summer, there is plenty of water to
transport therefore the cells are _______.
• Towards summer and fall, there is less
water, and the cells are _______.
• This creates a new tree ring each year.
Oxygen out and
carbon dioxide in
Tropisms
• Gravitropism – roots grow towards
gravity
• Phototropism – stems and leaves grow
towards light (photo)