SYSTEMS IN PLANTS

Plants are multicellular Organisms with

Two obvious distinguishing features:

They are usually green They cannot

Move from place to place.

SYSTEMS IN PLANTS

• Flowering plants have two

main “body systems:”

the root system and the shoot

system.

• These two body systems

work together to perform

all of the functions necessary

to keep the plant alive:

– exchanging gases with its

surroundings

– moving water and

nutrients around internally

– reproducing

SYSTEMS IN PLANTS

• The root system is typically the part of the plant that

grows underground. Its functions are to anchor the

plant, to absorb water and minerals from the soil, and to

store food.

• The shoot system of flowering plants is made up of

three parts: the leaf, the flower, and the stem.

• The leaf is where photosynthesis takes place.

Chloroplasts in a plant’s leaves use carbon dioxide,

water, and light energy to produce glucose and oxygen.

SYSTEMS IN PLANTS

• Flowers contain male or female reproductive structures. Male reproductive structures produce pollen grains. Female structures produce eggs. After eggs are fertilized by pollen, seeds form within a specialized structure called a fruit.

SYSTEMS IN PLANTS

• A plant’s stem supports the plant’s leaves

and flowers, and provides a way to

transport the materials the plant needs.

• People use flowering plant roots, leaves,

stems, and flowers (plus the seeds and

fruits that come from them) for food,

flavourings, fibres, and medicines.

PLANT TISSUE SYSTEMSPLANT TISSUE SYSTEMS

• Similar to stem cells in animals, meristematic cells

are undifferentiated plant cells that can form any

kind of specialized tissue.

• Plant tissues are classified into three tissue

systems, each containing a variety of specialized

cell types that carry out specific functions within the

plant.

PLANT TISSUE SYSTEMSPLANT TISSUE SYSTEMS

• The three major

tissue systems of

plants are

–dermal

–vascular

–ground

PLANT TISSUE SYSTEMSPLANT TISSUE SYSTEMS

• The dermal tissue system forms the outmost layer of a plant. It includes both epidermal and peridermal tissues. These tissues are what you see when you look at the leaves, stem, and rootsof a plant.

• Epidermal tissue (epidermis) is the thin layer of cells that covers the surfaces of leaves, stems, and roots. In woody plants, the epidermal tissue is replaced by periderm tissue, which forms barkon stems and large roots.

PLANT TISSUE SYSTEMSPLANT TISSUE SYSTEMS

• Some cells of the dermal tissue system absorb water and minerals from the surrounding soil. Others produce a layer of wax to waterproof the surface of leaves. Still others contain chemical irritants for defence.

PLANT TISSUE SYSTEMSPLANT TISSUE SYSTEMS

• A plant’s vascular tissue system is like a network of tubes that reaches from the roots up the stalk to the leaves. When a plant’s roots absorb water and nutrients from the soil, the vascular tissue system transports the water and nutrients to the various parts of the plant, where they are needed for growth.

PLANT TISSUE SYSTEMSPLANT TISSUE SYSTEMS

• There are two types of vascular tissue:

xylem and phloem.

• Xylem carries water and dissolved

minerals from the roots to the

rest of the plant. Water moves through

the tubes in one direction.

• Phloem transports solutions of sugars

produced during

photosynthesis, as well as other

dissolved nutrients and hormones.

In phloem tissue food materials may be

transported in either direction:

downward from photosynthesizing leaves

to stem and roots or upward

from the root and stem to the leaves.

PLANT TISSUE SYSTEMSPLANT TISSUE SYSTEMS

Ground tissue cells are part of the third major tissue of plants.

They are the filler between the dermal and the vascular

tissues.

Ground tissues perform a variety of functions, depending on

their location within the plant: In the green parts of the

plants, they manufacture nutrients by photosynthesis.

In the stems, they provide storage and support.

In the roots, they store carbohydrates

Home work

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