Plants and Their Adaptations Variations of Parts Roots Leaves Seed Dispersal Attraction of...
Transcript of Plants and Their Adaptations Variations of Parts Roots Leaves Seed Dispersal Attraction of...
Plants and Their Adaptations
Variations of Parts
RootsLeavesSeed DispersalAttraction of PollinatorsPhototropismGeotropism
Survival
As you watch this presentation, focus on how variations, adaptations, or behaviors enhance a plants’ survival.
Include:Roots Seeds
Stems Phototropism
Leaves Geotropism
Flower
Variations
o Variation is:– the difference between individuals of the same species– the process or act of changing
o Variation is necessary:– If all of the plants in a species were exactly
the same, they could all be taken out by disease or disaster.
Structure and FunctionComparing structure and function of parts andbehaviors helps us understand why variation is
necessary.
Structure is the form of an organism’s parts. Example: A pedal is structured like a landing strip for insects.
Function is what that part does. Example: The function of a petal is to attract insects.
http://commons.wikimedia.org/wiki/File:Mature_flower_diagram.svg
Common Plant Parts
Most plants, no matter how they look, share some common parts.
Most plants have:
RootsStemsLeaves Flowers
http://commons.wikimedia.org/wiki/File:Leaves-scan.jpg
Structure and Function
The structure and function of plant
parts show evidence of adaptation.
Examples Include: Defenses against consumers
Ways to attract pollinators
Seed dispersal to ensure survival
http://commons.wikimedia.org/wiki/File:Weberocereus_tunilla_-_The_Cactaceae.jpg
RootsRoots must adapt to their different
environments.
• Structure and Function:– Roots act as anchors to keep plants grounded.
– Roots take in water and minerals from the soil through tiny root hairs.
– Some roots can store food.
http://commons.wikimedia.org/wiki/File:Cycads_root.png
RootsSome roots spread out along the ground in search of
water in places where it rains often.
http://commons.wikimedia.org/wiki/File:Root.png
Some roots grow deeper into the
ground in search of water inplaces wherethe climate is dry.
Roots
http://commons.wikimedia.org/wiki/File:Root_rot_in_cicer_arietinum_(hydro-grown).jpg
Roots
Some roots begin on a stem rather than below the ground. They are used for support to prop or brace the plant.
http://commons.wikimedia.org/wiki/File:Ghana_roots.JPG
Roots
Soil
Roots
Some plants are able to store food in their roots for later use. These are called storage
roots.
Some examples include: sweet potatoes
carrots
beets
radishes
http://commons.wikimedia.org/wiki/File:Rabano-radish-raphanus-sativus.jpg
StemsStems must adapt to whatever environment
the plant is in.
o Functions:– Hold the plant upright and
support the leaves– Carry water up the plant and
food down from the leaves to other parts of the plant
– Defend plants: thorns, prickles, and stinging hairs
http://commons.wikimedia.org/wiki/File:Cirsium_undulatum_(4990344551).jpg
StemsMany stems are edible like
asparagus, broccoli, cauliflower, and celery.
Cinnamon: The bark is used as a spice.
Garlic and Onion: They are bulbs.
Ginger Root: The edible portion is a branched underground stem called a rhizome.
Potato: The edible portion is an underground stem that is also a tuber.
Sassafras Tree: The shoots and stem bark can be used to make root beer.
http://commons.wikimedia.org/wiki/File:Dracaena_sanderiana_close_up.jpg
Leaves Leaves have many shapes and sizes, all depending
on the environment and how much sunlight the plant needs.
http://commons.wikimedia.org/wiki/File:Leaves-scan.jpg
Leaves
Functions:Make food through
photosynthesis and release oxygen
Protect the plant: prickles and spines
http://commons.wikimedia.org/wiki/File:Photosynthesis.gif
LeavesNotice how some leaves have adapted to
function as a defense.
http://commons.wikimedia.org/wiki/File:Erythrina_zeyheri,_blaarstekels,_Krugersdorp.jpg
Flowers
Functions:A flower helps the plant
reproduce.
The flower contains the pollen and egg necessary to make a fruit which has the seeds in it.
Seeds
Seeds disperse differently depending on their structure:
Wind: Flowers can have a wing-like structure. Water: Flowers can have water-proof covering.Animals/Humans: Flowers can have burrs for
sticking to fur or clothing.Insects: Pollen sticks to insects as they move from
place to place.Some seeds can split and twist to throw seeds in all
directions.
SeedsWind: Maple seeds have a wing-like structure.
http://commons.wikimedia.org/wiki/File:Maple-seed.jpghttp://commons.wikimedia.org/wiki/File:Bumble_Bee_Gathering_Pollen.jpg
Insects: Pollen sticks easily to this bumble bee.
Seeds
Animals: This bison’s face is covered in cockleburs, which are the
Velcro®-like seed pods.
http://commons.wikimedia.org/wiki/File:Flickr_-_Furryscaly_-_Burface.jpghttp://commons.wikimedia.org/wiki/File:Sundari_seed.JPG
Water: The Heritiera littoralis seed has a water-proof covering.
Phototropism
Directional growth in response to the direction of the light source.
o Positive Phototropism: growth towards a light source– Plant shoot leaves exhibit positive
phototropism
o Negative Phototropism: growth away from light source – Roots usually exhibit negative
phototropism.
http://commons.wikimedia.org/wiki/File:Sunlight_on_Beech_roots_-_geograph.org.uk_-_1609346.jpg
http://commons.wikimedia.org/wiki/File:Phototropism.jpg
Geotropism Turning by a plant in response to gravity
oCharles Darwin documented the following:– Stems show negative geotropism (grow in opposite direction of gravitational pull)– Roots show positive geotropism (grow in direction of gravitational pull)
http://commons.wikimedia.org/wiki/File:Root_rot_in_cicer_arietinum_(hydro-grown).jpg
Sweet Potato PlantThis plant was sprouted in a shallow bowl of water in
a kitchen.
The leaves on the main sprout were facing the window and are reaching toward the light.The leaves on the
secondary sprouts are bending toward the light because they were facing away from the window.
The roots are reaching downward toward the ground. They are filling the bowl but always trying to go downward.