Plants Green: The color of life

Plants Dominant organisms on land Probably evolved from multicellular aquatic green algae that could not survive on land.

Characteristics of Plants Eukaryotic – has a nucleus Multicellular – more than one cell Autotrophic – photosynthesis - have chloroplasts w/chlorophyll Sessile - remains stationary Cell walls-contain cellulose which gives plants rigidity

What do plants need to survive? Sunlight Water and Minerals Movement of Water and Nutrients Gas Exchange Sugar CO2 O2

The Development of Plants Mosses and their relatives Ferns and Cone-bearing plants Flowering Blue green bacteria Water-Conducting Vascular Tissue Seeds Flowers Seeds Enclosed in Fruit Over time, plants have gone from simple to complex.

Ways To Classify Plants Non-vascular (moss) Vascular (all trees, vines, flowers) No Seeds (spores in mosses or ferns) Seeds (formed in a cone or fruit) No Flowers(gymnosperms such as pines, firs, spruces, etc.) Flowers (angiosperms)

Nonvascular Plants Moss and lichen are non vascular plants They don’t have tissues to moves nutrients and water and they stay small

Vascular Plants All other plants are vascular, they CAN move water and nutrients Can grow larger Xylem tissue: moves water Phloem tissue: moves food (sugars)

Plant Structures: have true tissues Dermal-“Skin” or protection(thick bark, spongy cork or tight sheath on stems) Ground – storage, structure & photosynthesis Vascular – for transport -Xylem carries water -Phloem carries sugars

Plant Structure (cont.) HAVE ORGANS… Roots Stems Leaves Flower

Why does a plant need roots? To absorb water and nutrients from the soil like a sponge and store them for later To anchor a plant in the ground

2 Types: Fibrous root & Taproot

Fibrous Root Found in Monocots Extensive, spread out Helps anchor topsoil Grasses

Taproot Found in Dicots One primary root Grow down to absorb deep water Storage for starches and sugar (food) Carrots, beats, radishes

A Root Has Layers Vascular Cylinder Epidermis Cortex

The outside layer of a root Is called the Epidermis The epidermis provides Root Hairs add extra surface area. Absorption The root cap pushes through the soil. Protection

The middle layer is the Cortex Vascular Cylinder Cortex The inside layer is the Vascular Cylinder. It moves the water and the nutrients

The Vascular Cylinder contains: Xylem Phloem Carries Water W (water) & X (xylem) are both at the end of the alphabet. (Pronounced Flow-em) Carries Food Sugar

Why does a plant need a stem? To produce leaves, branches and flowers To hold the leaves up to sunlight To transport nutrients from roots to leaves

1. Support leaves & flowers STEMS 2 main functions: 1. Support leaves & flowers 2. Transport water and nutrients throughout the plant

Types of Stems: NON-WOODY. SOFT GREEN TISSUE AS FOUND IN HERBACEOUS PLANTS WOODY AND VERY STRONG. THE STEM OF A TREE INCLUDES THE TRUNK, BRANCHES AND TWIGS

Why does a plant need leaves? For Photosynthesis Sugar For Transpiration For Gas Exchange CO2 O2 To Make Food To Move Water To “Breathe”

Common Features of Leaves Vein – tube- like vessels that carry water, sugar and minerals throughout the blade Blade – Contain cells that carry out photosynthesis Petiole – Short stalk connects leaf to stem

Leaf Structure Cuticle Upper epidermis Mesophyll Bundle sheath Vascular tissue Lower epidermis Guard cells chloroplast stoma

As water pressure in the Guard cells let water leave the plant. Guard Cells As water pressure in the guard cells decrease The size of the stoma decreases Stoma

As water pressure in the Guard cells let water leave the plant. Guard Cells As water pressure in the guard cells increase The size of the stoma increases Stoma

Looking at a cross-section of a leaf, you can see

Looking at a cross-section of a leaf, you can see Control the size of the stoma. Guard Cells

Looking at a cross-section of a leaf, you can see Stoma Allows gases to move in and out of the leaf.

Looking at a cross-section of a leaf, you can see Cuticle Outer waxy layer that protects against water loss.

Looking at a cross-section of a leaf, you can see Xylem Phloem Move nutrients and water through the plant.

Flowering Plants have: Monocot Mono = one cot = cotyledon (seed leaves) Dicot Di = two cot = cotyledon (seed leaves) Corn Seed Bean Seed Seeds

Flowering Plants have: Monocot Dicot Parallel Veins Branched Veins Leaves

Flowering Plants have: Monocot Dicot 3 3 4 2 4 2 5 1 5 1 6 6 8 7 Multiples of 3 Multiples of 4 or 5 Flowers

Flowering Plants have: Monocot Dicot Vascular Bundles Scattered Vascular Bundles In a Ring Stems

Flowering Plants have: Monocot Dicot Fibrous Root Taproot Roots

Plants can reproduce sexually by Plant Reproduction Plants can reproduce sexually by Seeds Cones

Seed Dispersal Seeds can be spread by: Animals Wind Water

Gymnosperms reproduce using cones.

Angiosperms reproduce using flowers

Parts of a Typical Flower How attractive! Careful! Petals Attract Insects Sepals Protect the Developing flower Parts of a Typical Flower

Parts of a Typical Flower Stamen Anther Filament Male part of flower Parts of a Typical Flower

(Sounds like “Pigtail”) Stigma Pistil Style Female part of flower (Sounds like “Pigtail”) Ovary Parts of a Typical Flower

Plant Reproduction Stems Roots Plantlets Plants can reproduce asexually by vegetative propagation Stems Roots Plantlets Stems, plantlets and roots can become a new plant.

Plants can reproduce asexually by Plant Reproduction Plants can reproduce asexually by plant propagation. Cuttings Grafting & Budding A “cut” from a plant can grow roots when put in soil. Two plants are attached to form one plant.

Plants can respond to their environment. Tropisms Winter Dormancy Plants can respond to stimuli such as gravity, light, and touch. A plant’s growth and activity can decrease or stop for a period of time.

Plants can adapt to their environment. Aquatic Plants Desert Plants Waterlilies have air-filled spaces to help oxygen move. Have extensive roots, reduced leaves and thick stems to store water. Coconut seeds float in water.

STOP

Photosynthesis Green plants use the energy of sunlight carbon dioxide CO2 + water sugars Sugar + oxygen O2 Green plants use the energy of sunlight to convert carbon dioxide and water into high-energy sugars and oxygen. 25

Photosynthesis The formula looks like this. 6 CO2 6 H2O C6H12O6 6 O2 light 6 CO2 + 6 H2O C6H12O6 + 6 O2 carbon dioxide water sugars oxygen The balanced equation looks like this. Now there are equal numbers of each element on both sides of the arrow. 26

Photosynthesis 6 Carbon 6 CO2 6 H2O C6H12O6 6 O2 light 6 CO2 + 6 H2O C6H12O6 + 6 O2 carbon dioxide water sugars oxygen The balanced equation looks like this. Now there are equal numbers of each element on both sides of the arrow. 27

Photosynthesis 18 Oxygen 6 CO2 6 H2O C6H12O6 6 O2 light 6 CO2 + 6 H2O C6H12O6 + 6 O2 carbon dioxide water sugars oxygen The balanced equation looks like this. Now there are equal numbers of each element on both sides of the arrow. 28

Photosynthesis 12 Hydrogen 6 CO2 6 H2O C6H12O6 6 O2 light 6 CO2 + 6 H2O C6H12O6 + 6 O2 carbon dioxide water sugars oxygen The balanced equation looks like this. Now there are equal numbers of each element on both sides of the arrow. 29