Characteristics of Plants Section 12.1

Characteristics of Plants Learning Goal: To explore the basic needs and make up of plants. Success Criteria: I know I am succeeding when I can… explain the basic conditions plants need in order to survive describe the specific adaptations that allow plants to survive under various conditions describe the basic structures common to vascular plants and explain the purpose(s) each structure serves explain the evolutionary relationships among various plant groups

Characteristics of Plants Plants perform the following functions to stay alive: produce food (glucose) and oxygen using photosynthesis exchange gases (CO2 and O2) with their surroundings transport water and nutrients throughout their bodies grow reproduce

The Phylogeny of Plants 3 major groups of vascular plants: the lycophytes and pteridophytes (club mosses; ferns and their relatives) the gymnosperms (conifers) the angiosperms (flowering plants) these groups of vascular plants can be distinguished by key evolved traits

The Phylogeny of Plants Cont’d… angiosperms contain cotyledons, which are structures that supply nutrients to the plant embryo plants with 1 cotyledon are classified as monocots plants with 2 cotyledons are classified as Amborellales, Nymphaeales, other early angiosperms, or eudicots

The Vascular Plant Body: Roots and Shoots most vascular plants have an underground root system and an above-ground shoot system

The Vascular Plant Body: Roots and Shoots Cont’d… vascular plants have three main non-reproductive organs: the leaf, the stem, and the root composed of three tissue types: dermal tissue, vascular tissue, and ground tissue

Plant Tissues

1. Dermal Tissue Forms the outermost layer of a plant Periderm tissue: Only on woody plants Forms bark on stems and large roots Epidermal tissue: Thin layer of cells covering the surface of leaves, stems and roots

Epidermal Can be specialized Leaf cells produce a waxy waterproof cuticle Root hairs to absorb water and minerals

2. Vascular Tissue transportation system Vascular bundle (veins) Xylem: Transports water and dissolved minerals from roots to the leaves   Phloem: Transports a sugar solution from the leaves to the roots

3. Ground Tissue Located between dermal and vascular tissue Variety of functions: Photosynthesis Food and water storage Structural support

2 main types of Ground tissue Palisade layer: main site of photosynthesis, near surface Spongy mesophyll: Interior of leaf, photosynthesize, loosely packed

The Vascular Plant Body: Roots and Shoots Cont’d… meristematic cells: unspecialized plant cells that can actively divide and differentiate to form specialized cells (located at the tip of roots and shoots ) lateral meristems cause plants to grow wider and apical meristems cause plants to grow taller specialized cells that make up plant tissues come from unspecialized cells during cellular differentiation

Characteristics of Plants Learning Goal: To explore the basic needs and make up of plants. Success Criteria: I know I am succeeding when I can… explain the basic conditions plants need in order to survive describe the specific adaptations that allow plants to survive under various conditions describe the basic structures common to vascular plants and explain the purpose(s) each structure serves explain the evolutionary relationships among various plant groups

Homework Answer 12.1 questions #1-4 on page 545