Plants??
What are Plants?
Plants are multi-cellular living organisms that are able to use sun light & water to make their own food.
Classifying Plants
How are Plants Classified? One way that plants can be classified is
by how they carry water. Plants can either be Vascular or Nonvascular.
What is Vascular Tissue??
Vascular tissue:
It is the tissue which supports the plant & carries food & water.
Note:
the word “ Vascular” is a Latin word meaning Vessel.
Nonvascular Plants
Do not have a vascular tissue (xylem and phloem).
Don’t have true roots, but are anchored into the soil by small “root-like structures”.
No true Stems ( parts looking like stems).
No Leaves but have small Leaf like structures .
Non- Vascular Plants
Why they don’t have true leaves?
They have no “ Veins” to transport & carry material throughout the plant.
So, How Do they grow?? They absorb water & nutrients directly from their surroundings.
How??Water in the plants carry
food & nutrients directly from cell to cell.
Why don’t Non-Vascular Plants grow tall??
Because Non-Vascular plants lack transport tubes that carry water & nutrients , so they must be close to a surface in order to absorb these materials directly from their surroundings.
Their small size allow them to absorb enough water to carry materials throughout the plant.
Mosses are Nonvascular Plants
Mosses are non- vascular plants.
They do not grow very large. They do not have true roots,
stems, and leaves. Mosses are actually made of
many tiny, dark green plants. If no enough water, they dry
and turn brown.(if it rains?)
Vascular Plants
Have a vascular system (xylem and phloem) that moves water through the plant quickly and effectively.
Because of this system, these plants can grow very large.
These plants have roots , stems and leaves.( all containing vascular tissue)
Vascular Plants:
Have roots : - Anchor the plant in
the soil.- Allow it to absorb
water & nutrients from the soil.
Have leaves: in which food is made by Photosynthesis.
Have stems:
- Allow them to transport food & nutrients to the roots & leaves of the plant through tubes found in stems.
Vascular Tissue:
Xylem: carries water &
nutrients from roots to every part of the plant.
Phloem: Carries food from
leaves to the rest of the plant.
Ferns are Vascular Plants
Ferns were one of the first plants on earth with a vascular system.
The roots of vascular plants, like ferns can branch out more because of the vascular system.
Vascular Plants Examples:
Tiny duckweed ( fraction of an inch long).
Giant redwood trees.
Cacti ( grow in deserts, which have little water)
Orchids ( grow in damp rain forest)
Vascular Non
Has a Vascular system
Has true roots
Has Xylem yes No
Has Phloem yes No
Has true stems yes No
Can grow large
Has true leaves yes No
Needs water to reproduce
Write an example.
yes
yes
yesyes
yes No
No
No
fern moss
Plant Roots
Functions of the root:
• Anchor the plant to the ground & are adapted to the plant needs & the environment.
• Absorb water and nutrients from the soil & pass them to the leaves
• Some act as food storage structures.
• Xylem in roots:
Take water and nutrients from root hairs and move them to the stem.
1) Tap Root:• One large, strong root
that pushes deep into the soil. ( anchors the plant firmly).
• Some of them store food ( used when plants make flowers & fruits).
• Some of them are used as food( Carrots & beets)
2) Fibrous root:• Thin & branching.• Forms a mat below
the surface of the ground.
• They spread & absorb water from a large area, taking in as much as possible.
Root Types:
2) Fibrous Root
Hold the plant in the soil.
Keep the soil from washing away.
Example: Grasses
Are often used to hold the soil because they have many fibrous roots.
3) Prop Roots:
Roots that grow above the ground.
Help hold the plant upright.
Examples:
Mangrove tree & Corn.
Stems:
Pipelines for transporting water & nutrients between roots & leaves.
Provide Support ( help the plant to stay upwards)
Vascular tissues in stems & also in some large roots are gathered into bundles
Bundles are either scattered through the plant or arranged in a ring.( in tress of flowering plants)
Stems Provide Support??
Stems grow from the ground & hold the leaves up to the sun light.
Stems found in trees & other tall plants have woody cells in their stems ( making the stem stronger)
Note: in plants without woody cells , water pressure holds the stem upright.
Stems
Droopy Stem:- It’s a clue that a
plant might need water.
- Some plants as Cacti store water & food in fleshy stems.
New plants can grow from some stems
Example:
Strawberry plants have stems called runners, which grow sideways( new plants grow from runners).
Leaves
Make food by the process of Photosynthesis.
Manufacturing food:
uses:
- Light energy.
- Carbon dioxide.
- Water
To make:
Sugars.
Note: Photo = light. Synthesis = to put
together ( to make food ).
Photosynthesis:
The process in which plants make food by using water from the soil, CO2 from the air & energy from sun light.
Water: xylem cells bring it from the soil
Light energy: absorbed by a green pigment contained in chloroplasts where photosynthesis take place.
CO2 : leaves get them from the air.
Photosynthesis:
Products include: Food: Sugars
( glucose) carried by phloem cells in the veins to all plant parts.
Oxygen: a waste product go into the air.
Epidermis:
Outer layer of cells in a leaf.
It protects the leaf from damage.
Some plants have waxy coating on the epidermis( help keep moisture inside the leaf).
Some water escape through Stomata:
Tiny holes on the underside of a leaf.
They open & close to let CO2 in & O2 out.
They close when water is in short supply.
Top Related