Plant Structures Roots, Stems, and Leaves

What are plants? Photosynthetic ,eukaryotic , multi-cellular organisms . The plant structure can be classified into two major regions : The shoot system (stem and leaves); located above ground The roots (located underground)

Specialized Organs in Plants Stems Support for the plant body Carries nutrients throughout plant Defense system to protect against predators and infection Few millimeters to 100 meters

Two Main Types of Stems Herbaceous Stem Woody Stem Green, fairly bendable Covered with bark

Specialized Organs in Plants Leaves Main photosynthetic systems Susceptible to extreme drying Sight of oxygen/carbon dioxide intake and release

Specialized Organs in Plants Roots Absorbs water and nutrients Anchor plant to the ground Hold soil in place and prevent erosion Protect from soil bacteria Transport water and nutrients Provide upright support

Specialized Tissues in Plants Plant tissue systems Exist within the root, stems, and leaves Dermal tissue Vascular tissue Ground tissue

Specialized Tissues in Plants Dermal Tissue Outer covering Single layer of cells acts as protection

Specialized Tissues in Plants Vascular Tissue Transport System Subsystems Xylem Phloem Subsystems are used to carry fluids throughout plant

Vascular Tissue System Xylem -carries water from the roots to the rest of the plant. Phloem- carries sugar from the leaves to the rest of the plant

Kinds of Plants There are two kinds of plants; non-vascular plants which don’t have xylem and phloem and vascular plants which do have xylem and phloem.

Specialized Tissues in Plants Ground Tissue (cortex) Cells between dermal and vascular tissue Provides structure Sometimes involved in photosynthesis

Common Types of Plant Tissue Parenchyma Thin cell walls, large vacuoles Collenchyma Strong, flexible cell walls Sclerenchyma Extremely thick, rigid cell walls

Stem Structure Dermal tissue-protection Vascular tissue-transport Composed of three tissue layers Dermal tissue-protection Vascular tissue-transport Ground tissue-sometimes performs photosynthesis Contain nodes – attachment for leaves Internodes – regions between the nodes Buds – undeveloped tissue Petiole-the stalk of the leaf, which joins the leaf to the node of a stem.

Stem Types Stem Types Monocot – vascular bundles are scattered throughout Distinct epidermis Dicot – vascular tissue arranged in a cylinder Pith – parenchyma cells inside the ring

Roots Root Functions Anchor plant Absorb water Absorb nutrients

Root Structure Root Structure can be divided into four layers Epidermis-outside layer (protection) Cortex-typically stores food Endodermis-control movement of materials into vascular tissue Central cylinder – vascular system Key role in water/mineral transport

Root Structure

Roots Types of Roots Taproots Found in dicots Long, thick root Hickory and oak trees Fibrous roots Found in monocots No single root larger than any other Many thin roots

Leaves Main sight of photosynthesis Consist of: Blade – thin flattened section Petiole – stalk that attaches stem to blade Covered by epidermis and cuticle Create water proof barrier

Structure Helps to catch more light energy Wide Helps to catch more light energy Thin Help get carbon dioxide from bottom to top of leaf for photosynthesis

Leaves Leaf Functions Photosynthesis – occurs in the mesophyll Palisade mesophyll – absorb light Spongy mesophyll – beneath palisede level Stomata – pores in the underside of the leaf Guard Cells – Surround the stomata

Leaf structure Greener on top CO2 gets in here What kingdoms are the above organism members of? What characteristics do they have in common? How are they different? What kingdoms are the above organism members of? What characteristics do they have in common? How are they different?

Organization of Living Organisms Vascular Plants Is composed of Organ Systems are composed of Organs Tissues Cells are composed of Organ Systems Organs Tissues Cells