High School Biology Class CHAPTER 24: Plants High School Biology Class

Kingdom Plantae Members of the Kingdom Plantae dominate the land and many bodies of water while exhibiting a tremendous amount of diversity. There are more than 270,000 different plant species, and new plants continue to be discovered in the Tropical Rainforests.

Without plants, life as you know it would not exist. Kingdom Plantae 1) Almost all organisms on Earth depend on the photosynthetic ability of plants. 2) Plants also produce the oxygen you breath, the food you eat, and even the paper used to print your textbook.  3) Furthermore, plants are a source of many medicines that help to keep you healthy.  _____________________________________ Without plants, life as you know it would not exist.

What is a Plant? Plant - any of various photosynthetic, eukaryotic, multicellular organisms that produce embryos, contain chloroplasts, have cellulose in their cell walls, and lack movement. Mosses, ferns, conifers, cacti, and tulips are all different types of plants.

What is a Plant? All plants are photosynthetic. All plants are multicellular. All plants are eukaryotic. All plants can reproduce sexually. All plants have cellulose in their cell walls.

What is a Plant? Most plants absorb nutrients by their roots. Most plants form mycorrhizae with fungi. Most plants prevent water loss by a thick waxy coating called a cuticle. Most plants use stoma (pores) to let oxygen out and carbon dioxide inside of them.

What is a Plant? Some plants are less than 1 mm in width. Some plants grow more than 100 m (328 ft) in height. Some plants complete their life cycles in 1-2 weeks, while others may live 5,000 years.

Plant Facts In their characteristics, plants are most similar to the Green Algae (plant-like protists) that live in the water. According to the fossil record no organism lived on land until about 430 million years ago when a layer of ozone formed. Scientists hypothesize that fungi and plants were the first organisms to invade land.

Plant History 1. Absorb nutrients from their surroundings. Before living on land, plants needed to do 3 things: 1. Absorb nutrients from their surroundings. and fungi

Plant History 2. Prevent their bodies from drying out. Cuticle Stoma Before living on land, plants needed to do 3 things: 2. Prevent their bodies from drying out. Cuticle Stoma Guard Cells

Specialized Plant Parts a. Cuticle - waxy layer that covers the non-woody above ground parts of most plants. b. Stomata - pores that permit plants to exchange oxygen and carbon dioxide. c. Guard Cells – a pair of specialized cells that border each stoma.

Plant History 3. Reproduce without water. Before living on land, plants needed to do 3 things: (Pollen permits the sperm of most plants to be carried by wind, water, or animals.) 3. Reproduce without water.

More Plant History & Parts Plants became successful on land because… a. Most plants have a vascular system (vessels or ducts) that transport materials through the body. i. Phloem – soft walled cells that move nutrient/food. ii. Xylem – hard walled cells that move mineral/water. Xylem Phloem

More Plant History & Parts Plants became successful on land because… b. Some plants have flowers (reproductive structures) that produce pollen or seeds. i. Pollen – encloses sperm and carried by wind, etc. ii. Seeds – protects and contains plant embryo.

Plant Seeds Four advantages of seeds over pollen: i. Protection ii. Delayed Growth iii. Dispersal iv. Nourishment

Four Types of Plants (The 12 Phlya of Plants)

1. NONVASCULAR PLANTS Lack true roots, stems and leaves. Small in size (usually < 3 cm tall). Nutrients and water transported by osmosis and diffusion. Require water for sexual reproduction. Rhizoids - hair-like projections that anchor the plant to growing surfaces.

Mosses, Liverworts, and Hornworts 1. NONVASCULAR PLANTS Examples: Mosses, Liverworts, and Hornworts

2. SEEDLESS VASCULAR PLANTS Have both a phloem and xylem. Can grow to large sizes. Produce spores (not seeds). Have true roots, stems and leaves. Rhizomes - horizontal underground stems.

2. SEEDLESS VASCULAR PLANTS Have Distinctive Body Forms: a. Shoot - part of a plant’s body that grows mostly upward. b. Root - part of a plant’s body that grows mostly downward. c. Meristems - zones of actively dividing plant cells that produce plant growth.

MERISTEM SHOOT MERISTEM ROOT MERISTEM

2. SEEDLESS VASCULAR PLANTS Examples: Ferns, Club Mosses, Horsetails, Whisk Ferns

Vascular Plants These are currently the most complex organisms of the plant kingdom. Can be separated into two subtypes: i. Gymnosperms ii. Angiosperms

3. GYMNOSPERMS “Naked Seeds” Plants whose seeds do not develop within a sealed container (fruit). Seeds: Male and female cones Wind pollination Water pollination Animal pollination

3. GYMNOSPERMS Examples: i. Conifers (redwood, pine, spruce, etc.) ii. Cycads iii. Ginkgo (male and female = separate trees) iv. Gnetophytes

4. ANGIOSPERMS “Seed Cases” Plants which produce seeds that develop while enclosed within a specialized structure (fruit). Most successful of all the plant groups. Flowers promote pollination and fertilization. Seed Cases (Fruit)

Angiosperm Parts a. Flowers - reproductive structures that produce pollen and seeds. b. Fruits - structure in which seeds of angiosperms develop and are used for seed dispersal. c. Endosperm - supply of stored food inside of seeds.

Angiosperm Types Angiosperms can be divided into two sub-categories of plants as well: i. Monocots ii. Dicots

Irises, Tulips, Wheat, Corn, Rice, Grass Angiosperm Types Monocots - flowering plants that produce seeds with one seed leaf. - Usually produce flower parts in multiples of three and have long narrow leaves with parallel veins. - Examples: Irises, Tulips, Wheat, Corn, Rice, Grass

Angiosperm Types Dicots - flowering plants that produce seeds with two seed leaves. - Usually produce flower parts in twos, fours, or fives and have branching or netted veins. - Examples: Daises, Sunflowers, Lettuce, Beans, Peas, Apples, Roses, Tomatoes, Peanuts

Plants Are Beneficial 1. Many Plants are valuable food sources for humans. - Fruits (contains seeds) - Vegetables (non-reproductive parts) Examples: apples, bananas, melons Examples: broccoli, lettuce, cabbage

Plants Are Beneficial 2. Many Plant parts are important foods. - Root Crops (provide starch) - Legumes (provide protein) Examples: potatoes, yams, carrots Examples: peas, beans, alfalfa

Plants Are Beneficial 3. Plants are used in many food products - Wheat - Corn - Rice Examples: breads, pastas, flour, cereal Examples: grits, corn oil, margarine, starch Examples: brown, white, baby food

Plants Are Beneficial 4. Plants have nonfood related uses as well. - Rubber (latex) - Fuel-grade Ethanol (gasoline) - Fibers (clothing, rope, paper) - Wood (paper, heating/cooking, building homes)

Plants Are Beneficial 5. Plants are used as medicines. Examples: a. Caffeine (tea leaves act as a stimulant) b. Codeine (poppy fruits relieve pain) c. Cortisone (yam tubers relieve allergies) d. Ephedrine (stems act as decongestant) e. Taxol (tree bark reduces cancer tumors)

Any Questions? “Embrace hard things and your mind will blossom.” --Japanese proverb “Great oaks from little acorns grow.” --Latin proverb