Unit 8- Plants

Soil

• Complex mixture of – Sand, Silt, Clay, Organic

matter

• Types- – Sandy-– Clay- – Loamy-

Essential Plant Nutrients (p 591)

• Inorganic nutrients plants need besides water and carbon dioxide– Nitrogen- part of

proteins, nucleic acids, chlorophyll, ATP, (color)

– Phosphorous- DNA, ATP

Essential Plant Nutrients

– Calcium- cell walls and membranes

– Potassium– required for stoma opening & closing

– Magnesium- part of chlorophyll

– Sulfur- part of proteins

Specialized Plant Tissues

• Meristematic Tissue- • (p 586)– Plant tissue where

cells continuously divide, areas that grow

– Apical meristem- • Located at the ends

of stems and roots, plants grow taller, roots grow deeper

Specialized Plant Tissues

– Lateral Meristems-• Allow roots and stem to

grow in diameter• Vascular cambium-

– Produces vascular tissues, increases the thickness of stems

• Cork cambium- – Forms the outer

covering of the stem

Specialized Plant Tissues

• Epidermal- (p 584)– Outer layers of leaves,

stems, & roots, protects, absorb water

• Parenchyma- – Storage, make up most

of the roots we eat

Specialized Plant Tissues

• Collenchyma-– Cells have thicker walls than

Parenchyma– Support regions of a plant– Ex. Celery stalks

• Sclerenchyma- – Cells have tough thick cell

walls, strengthen, support the plant• Example - hemp fibers for

making rope • Example - hard nut and seed

shells

Specialized Plant Tissues

• Vascular Tissue- – Transports materials

• xylem- transports water • phloem- transports food

Roots

• Anchor plant and absorb water and nutrients from soil

• Taproot- one main primary root

• Ex. carrot, radish, dandelion

Roots

• Fibrous roots- • Many smaller secondary

roots• Ex. grass, rye• Root Hairs– Thin walled, – Increase surface area

exposed to soil– Absorb water and

nutrients

Roots

• Monocot- usually has a ring of xylem and phloem around the central cylinder (stele) (p 589)

• Dicot- usually has central column of xylem in central cylinder (stele) with radiating arms (p 589)

Stems

• Hold leaves up for photosynthesis and transport materials to and from leaves

– Monocot- vascular bundles are scattered through out the stem (p 594)

– Dicot- vascular bundles form a ring around the outer edge of the stem (p 594)

Woody Stems (trees)

• Tree Rings– Annual rings formed

from vascular tissue that grows each year

– Age of tree– Weather conditions