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 Reproductive Stems Roots Leaves Flowers Fruits Seeds

Seeds Bean Seed 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? Provides anchorage 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 Compound Leaf A leaf with many blades 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

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 Peduncle Sepals Calyx 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 Dry 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

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