Plant Systems: Structure and Function Objectives: 1.

WHAT IS A PLANT? multicellular eukaryotic non-motile autotrophic (photosynthesis, chlorophyll)

TYPES OF PLANTS

WHAT DO PLANTS NEED? Plants photosynthesize, they do not need to ‘hunt’ for their own food (non-motile so they do not need complicated nervous, skeletal and muscle systems) They do need to: exchange gases with their environment Absorb water and nutrients and transport these around the plant Reproduce (sexually and non-sexually)

PLANT SYSTEMS: ROOTS AND SHOOTS The shoot system has 2 main functions: 1. photosynthesis 2. reproduction The root system has 3 main functions 1. anchor the plant 2. absorb H2O and minerals 3. store food

ROOT SYSTEMS There are 2 main types of root systems: Fibrous Root Tap Root (monocots) (dicots) adapted to increase surface area for absorption shallow depth in soil grasses, lilies adapted to anchor (esp. huge plants like trees) and storage grow deeper into soil carrots, trees, dandelions

SHOOT SYSTEMS CO2 + H2O  C6H12O6 + O2 There are 3 parts to stem systems: 1. LEAF Main photosynthetic organ (light energy) CO2 + H2O  C6H12O6 + O2 (glucose) Organelles in the leaf called chloroplasts are responsible for this reaction See p. 127 for leaves that have been adapted for support (tendrils), protection (spines) and reproduction (colour)

2. FLOWER Designed for sexual reproduction Can be male, female or, most often, both Pollination (male pollen landing on female stigma) can occur with the aid of wind (grass, maple trees), insects (bees, butterflies, flies), birds (humming birds) or even bats (Dracula)

The Flower

The Flower Male reproductive structures produce pollen Female reproductive structures produce eggs Eggs are fertilized by pollen Male: Stamen Anther Filament Female: Pistil/Carpel Stigma Style Ovary

The Flower - Fertilization After fertilization, female parts form seeds Seeds are contained within a fruit Fruit helps spread seeds away from plant http://www.personal.psu.edu/mnm14/blogs/biology_12_lab_flowering_plant_reproduction/lessons/02---plant-structures-pollination-and-reproduction.html

3. STEM Main function is support of leaves and flowers for maximum photosynthesis and pollination Transports sugars from the leaves to roots and roots to leaves in spring (think maple syrup) Transports and water, minerals and nutrients from the roots to the leaves and developing fruit

Your Task HW: p.128 #2,4,5,6,7

Plant Tissues

Plant Tissue Types There are 3 main types of plant tissue: Dermal Ground Vascular Each of these tissue systems includes a variety of specialized cells

Just like humans start off a unspecialized stem cells, plants start off as undifferentiated cells These meristem cells only grow in the meristematic regions of a plant After they appear, and depending on where they are, the meristem cells will differentiate into specialized cells

Dermal Tissue Forms outermost layer of a plant. Epidermis can be specialized: Epidermal root cells can form root ‘hairs’ to absorb water and minerals. cross section of a root

Dermal Tissue Epidermal leaf cells produce a waxy waterproof cuticle which stops intruders Glandular ‘trichomes’ on stems and leaves can produce toxins or even sticky stuff to prevent predators

Vascular Tissue – 2 types Xylem Transports water and dissolved minerals from the roots to the leaves. Elongated cells joined to make tubes Grow a thick cell wall then die – means there is great support and no cytoplasm in the way to impede transport Wood is actually old, non-transporting xylem cells

Vascular Tissue Phloem Transports products of photosynthesis, a sugar solution, around the plant. (up and down) Elongated cell like tubes remain alive at maturity Bark is old, non-transporting phloem cells

Xylem and Phloem

Ground Tissue “The Filler” Located between the dermal and vascular tissue. Perform a variety of functions: Photosynthesis Food and water storage Structural support

Your Task Read pages 129 – 133 Answer Questions #1 - 6