Plant Anatomy and Physiology

Plant Anatomy and Physiology Just the Concepts

Anatomical Features and Their Functions

Objectives • Describe the structures, types, and the function of seeds; • Describe the components, the types, and the functions of roots; • Describe the structures, types, and the functions of stems; • Describe the structures, types, and the functions of leaves; • Describe the major parts of a flower and their functions; • Describe the types and forms of flowers; and • Describe the structures, types, and the purpose of fruit.

Plant Parts • Vegetative parts • Stems • Roots • Leaves • Reproductive • Flowers • Fruits • Seeds

Seeds • Types of seeds • Monocot • These seeds have one cotyledon • Dicot • These seeds have two Cotyledons Bean Seed

Seeds • Seed Structures • Seed Coat • Protects the fragile contents of the seed until germination conditions are met • Germination: When the seed sprouts • Embryo • Tiny plant that eventually grows into a mature plant • Cotyledons • Embryonic leaves that are the first to emerge from the soil surface • Food storage in dicots

Seeds • Seed Structures • Epicotyl • Becomes stem • Plumule • Becomes leaves • Radicle • Becomes root • Endosperm • Food Storage in monocots

Seeds • What are seeds used for? • Protect genetic information of the new plant • Nourish it when it germinates • The seed coat protects a seed while it is transported • How can a seed be transported? • Air • Water • Animals • How?

Roots • Types of roots • Fibrous root system • Many small roots spreading throughout the soil with no main root structure • Example: Grass, Petunia, Palm • Taproot system • One central root with many small branches spreading throughout the soil • Example: Carrot, Radish, Beet

Roots • Parts of roots • Primary Root • First root to emerge from the seed • Secondary Root • Sometimes called lateral roots • Branch out through the soil • Root Cap • Cell division causing root growth is done here • Root Hairs • Smallest parts of the root • Absorb water that contains dissolved nutrients

Roots • What does a root do? • Grows in the soil (or other media) • Two or three things • Provides anchorage • Absorb water and nutrients • Sometimes store food for the plant • In the form of sugars

Stems • Stems can look very different depending on the species of plant • Can be vertical or horizontal • Some are modified for climbing • Some store water or food • Types of stems • Herbaceous stems • No stiffened ligneous structure • Generally frail • Example: Tulip, Grass, most annual plants • Ligneous stems • Contain rigid structures, usually known as wood • Very strong • Example: Trees, Shrubs, Bushes • Specialized Stems • Several different types • Modified to serve a specific purpose for the plant

Stems • Specialized Stems • Bulb • Short flattened stem with several fleshy leaves • Grow beneath the soil • Produces a new plant each year • Corm • Spherical structure similar to a bulb • No layers • Dies each year but produces new corms for the following year • Rhizome • Underground stems that grow horizontally • New plants will sprout and emerge as this stem creeps under the soil surface • Stolon • Similar to the rhizome, but grows above ground • Can be called a runner • Tuber • It is the end of a rhizome that has swollen up with stored food • New plant will grow from the eyes of the tuber • Tendril • Slender structure used to attach to a support • Can be twisty, sticky, or hooky

Stems • Parts of a stem • Internode • Section of stem between nodes • Node • Location on stem from which leaves and branches grow • Terminal bud • AKA – apical bud • Bud at the end of stem growth • Usually found on perennial plants • Axillary bud • Form at the node and produce a new stem • Xylem • Vascular tissue in the stem that moves water and dissolved nutrients from the root to the rest of the plant • Phloem • Vascular tissue in the stem that moves food that was made in the leaves to other parts of the plant • Xylem up – Phloem down

Stems • What do stems do? • All stems • Provide support • Position the leaves • Responsible for size and shape of the plant • Transport water, nutrients, and food • Allow new growth • Some stems • Green stems produce food • Store food • Distribute growth

Leaves • Parts of a Leaf

Leaves • Parts of a Leaf • Stomata • Very important pores found on the underside of most leaves • Allow water and oxygen to escape and carbon dioxide to enter

Leaves • Types of Leaves • Simple Leaf • Has only one blade on the petiole • Compound Leaf • A leaf with many blades

Leaves • Types of Leaves • Vein Pattern • Parallel • Veins never cross, run parallel to midrib • Found in monocots • Pinnate • Veins branch off the midrib • Found in dicots • Palmate • Veins form a network, originate from common point at the base of the blade • Found in dicots

Leaves • Leaf Arrangement • Three Types • Alternate • Leaves grow one at each node alternating one side of the branch or stem to the other • Opposite • Leaves grow two at each node on either side of the branch or stem • Whorled • Leaves grow several at each node rotating around the branch or stem

Leaves • What do leaves do? • Photosynthesis! • They make food for the plant • Transpiration • Cool the plant • Some leaves store food • Leaf blade collects sunlight • Petiole supports the leaf and holds it away from the stem • Midrib provides structure to the leaf and transport food and water

Parts of a Flower

Parts of a Flower • Petals • Colorful leaf-like structures • Attract animals and insects • Peduncle • Stem of the flower • Provides support • Sepals • Green leaves that protect the flower before it opens • Calyx • All sepals fused together

Parts of a Flower • Female: Pistil • Stigma • Sticky part of pistil • Receives pollen • Style • Rod that holds up stigma • Ovary • Contains the eggs • Ovule • Reproductive cell (eggs) that become seeds once fertilized

Parts of a Flower • Male: Stamen • Filament • Stalk-like structure that holds up anther • Anther • Sack-like structure that holds pollen • Pollen • Contains reproductive cells

Flowers • Types of Flowers • Sympetalous • Petals fused together • Polypetalous • Many individual petals • Actinomorphic • Symmetrical on many axis • Funnel or bell shaped • Zygomorphic • Bilateral symmetry – only one axis

Flowers • Types of Flowers • Terminal • Grow from the end of a branch or stem • Axillary • Grow from the junctions of stems and leaves

Flowers • Types of Flowers • Single Flower • Plant with a single flower growing at the tip of the stem • Cluster • Three or more flowers branched together • Inflorescence • Many flowers growing and blooming independently on one peduncle

Flowers • Types of Flowers • Perfect flower • Contains male and female parts • Imperfect flower • Contains only male or only female parts, not both • Complete flower • Contain sepals, petals, pistil, and stamen • Incomplete flower • Missing either sepals, petals, pistil, or stamen Imperfect flowers are always incomplete Incomplete flowers are not always imperfect

Fruits • Once fertilization occurs, the flower is no longer needed and dries up. The ovary of the flower becomes the fruit of the plant • Name some different fruits • How are these fruits different? • How are they the same?

Fruits • Types of fruits • Fleshy fruit • Fibrous structure that surrounds the seed • Pome • Several seeds • Drupe • Single seed • Dry fruit • Formed in a pod or hull • Pod • Definite seam • Hull • No seam • Caryopsis • Thin wall • Samara • Wings attached

Fruits • What do fruits do? • Seeds are produced in the fruit • Protects the seed • Provides a mode of transportation • Offers the seedling a bit of fertilizer • Directly and/or indirectly • Fruits are generally the most valuable part of a crop • Fruits must be sufficiently mature to guarantee viable seeds • Why is it important to the plant for seeds to be produced?

Fruits • Does a producer (like a farmer) want their plants to produce seeds? • This is a trick question • Some plants are grown to produce as many seeds as possible • Like what? • Some plants are grown to not have seeds • Like what?

Fruits • Fruit or Veggie? That is the question • Carrot • Apple • Peach • Celery • Cucumber • Tomato • Watermelon • Zucchini • Green Bean • Coconut • Pinto Bean Veggie Fruit Fruit Veggie Fruit Fruit Fruit Fruit Fruit Fruit Seed

Plant Anatomy and Physiology