Vascular Plant Structures Dermal tissue Ground Tissue Vascular

Vascular Plant Structures Dermal tissue Ground Tissue Vascular Tissue

Vascular Plant tissues are organized to help split up the functions of the plant. Vascular tissue conducts water and material, while the dermal helps protect and the ground tissue makes up the inside.

Dermal Tissue Dermal tissue is the outside of the plant. In non-woody plants, the layer is called the epidermis and is covered with a cuticle layer to prevent water loss In woody plants, the tissue is a collection of dead cells called cork which contain a waterproof chemical. These layers also help in gas exchange and absorption of materials.

Ground Tissue Make up the inside of the plant parts. Consist of thin and thick walled cells that perform different functions In the leaf these cells store chloroplast that perform photosynthesis. In the stem and root, these cells mainly store water, sugar and starch for the plant.

Vascular Tissue Contain two types of cells; Xylem and Phloem. These cells are packed like pipes that carry fluids and dissolved particles throughout the plant.

Xylem Thick walled cells that conduct water and materials from the root through the stem to the leaves. Type 1 is tracheid. Narrow, elongated and water flows through pits.

Xylem Continued In flowering plants there is a second xylem tissue to help water flow faster. Vessels are wider than tracheids and have larger perforations to help aide in water flowing quicker.

Phloem Tissue Cells that conduct sugar and other materials throughout the plant. Cells contain cell membrane, cytoplasm and cell wall but either lack organelles or have modified ones.

Phloem continued Conducting tubes are called sieve tubes. Pores in the walls of neighboring sieve tubes allow materials to move freely from cytoplasm of one to the other. Companion cells on each sieve tube perform metabolic activities, protein synthesis and cellular respiration.

Major Plant parts Roots Stems Leaves

Roots are for absorption Roots also anchor plants and store nutrients like sugar and starches. Parts include cap, apical meristem or growing region, hairs, elongation and differentiation.

Types of Roots Tap root- has one main root with secondary roots growing off of.

Fibrous roots These types of roots have a highly branched network of roots that are usually the same in size.

Adventitious Roots These roots grow above the ground or from above ground stems

Root cross section Cortex surrounds the vascular tissue. Part of the ground tissue Epidermis layer just behind the root cap contain root hairs. Vascular tissue contain xylem/phloem

Stems Support the leaves and contain the vascular tissue. Different stems perform different functions. Ex. Cactus stores water, potato stores nutrients

Stems continued Leaves attach to stems at nodes. Area between 2 nodes is the internode Buds that grow into branches are also attached to a node.

Non-woody stems Usually call herbaceous plants No bark or cork surrounding the epidermis layer Must have cuticle layer to conserve water Pith is the ground tissue Stomata in the epidermal layer allow for gas exchange

Woody Stems Surrounded by cork and annual layers grow to form wood. Heart wood in the center no longer conduct materials and provide support Sapwood lies outside heartwood and conduct materials

Woody vs. Non-woody

Differences Cuticle vs. cork Scattered vascular bundles vs. radial Xylem and phloem create wood layers Size and strength vs. support

Leaves Attach to stem at the petiole Photosynthetic portion of a plant Contain chloroplast to capture sunlight Simple vs. compund

Simple vs. compound

Leaf parts Cuticle-conserves water Epidermis- outer layers top or bottom Palisades- contain chloroplasts Mesophyll- site for photosynthesis Stoma-gas exchange Guard cells-control stoma

Microscope view of leaf

Transportation in plants When stoma open, water is lost Transpiration is the loss of water 90% of water taken in by roots is lost during transpiration. Xylem is continuous from root to leaves so when water is lost cohesion causes root to pull water in. Process is like drawing liquid from siphon

Transportation continued Water gets into roots through osmosis Stomata open = water loss Guard cells close stoma = no loss of water Guard cells stay close during times of drought Water pressure in guard cells control the opening or closing