Plant Anatomy and Physiology

Early Plant Ancestors

All were Aquatic

Stipe: Holds plant upright

Rhizoid: Anchors algae

Chloroplast

VacuoleCell Wall

Green Algae Structure

Chloroplast

VacuoleCell Wall

True Roots

Stem

Leaf

What did plants have to do to make the move to land?

Put down Roots

Algae absorb the water they need from surrounding; rhizoids anchor

Plant roots help them absorb water and nutrients

What did plants have to do to make the move to land?

Develop a functional stem

Algae absorb what they need from their surroundings; also one cell thick

Plants have a stem which transports glucose and water to the whole plant

What did plants have to do to make the move to land?

Prevent water loss

Algae live in water; no need to control water; absorb what they need

Plants developed a cuticle (waxy outer layer) to prevent loss

What is the function of Roots?

What is the function of Roots?

• Transport water and nutrients throughout the plant.

• Structure and support

Two types of roots: Fibrous

Mainly lateral roots branching from one main point

Two types of roots: Tap

One main root; lateral roots

extending from the tap root

What type of root?

Fibrous

What type of root?

Tap

What is the function of stems?

What is the function of stems?

• Stems are the main highway for the transport of glucose and water.

• Vascular tissue makes up core of stems.

Plant tissue: Vascular

• Location: Core of the stem

• Function: Transports glucose and water throughout plants

Components of Vascular Tissue: Phloem

• “Phloem down below em”

• Glucose is made in the leaves of a plant.

• Phloem transports glucose down throughout the plant.

Components of Vascular Tissue: Xylem

• “Xylem to the skylem”

• Vascular tissue is used to transport materials throughout the plant.

• Xylem transports water up throughout the plant

What is the function of leaves?

What is the function of leaves?

• Leaves are the site of photosynthesis.

• Photosynthesis is the process in which plants capture energy from the sun and carbon dioxide to make glucose

Leaf Structure

Stem

Cuticle

• Waxy outer layer which prevents water from leaving the cell

• Found on the top side of leaves

Stomata

• Found on the underside of leaves

• They are tiny openings that allow water to move in and out the leaf.

Plant Tissue: Dermal

• Location: Outer most layer of tissue.

• Function: Prevent water loss and protection

Leaf Venation:

• Net venation: veins are spread out on the blade in a net. Like the network of veins in our bodies.

• Parallel venation: veins are lined side by side (parallel) on the blade.

Plant Responses: Phototropism*

• Plants response to light.

• Leaves will bend toward the light to maximum photosynthesis.

Gravitropism

• Plants response to gravity

• Positive Gravitropism: Roots grow down

• Negative Gravitropism: Stems grow against gravity

Thigmotropism

• Plants response to touch

• Life: Plants 4:00