Ch. 23-26 “Introduction to Plants ”

1. Ch. 23-26 “Introduction to Plants”

2. I. Adaptations of Plants A. Today’s plants probably evolved from green algae. B. To survive on land, plants had to be able to do three things: 1. Absorb nutrients 2. Prevent water loss a. Cuticle-waxy protective covering of a plant b. Stomata-pores in the leaves that allow for the exchange of gases. c. Guard cells-specialized cells that regulate the opening and closing of the stomata. 3. Reproduce on land a. Pollen-contains the sperm and allows it to be carried by wind or animals instead of water.

3. Cross-section of leaf

4. II. Characteristics of Plants A. Cell walls made of cellulose B. Multicellularand eukaryotic C. Autotrophic – produce own food through photosynthesis D. contain chloroplasts – structure that contain green pigment chlorophyll

5. III. Kinds of Plants A. Nonvascular Plants 1. Do not have a vascular system. 2. Need water for sexual reproduction. 3. Examples include mosses, liverworts, and hornworts.

6. B. Seedless Vascular Plants 1. Have a vascular system - internal system of interconnected tubes and vessels for transporting food and water. a. phloem-transports food. b. xylem-transports water. 2. Have spores with thick walls to prevent drying out 3. Examples include ferns, club mosses, horsetails

7. C. Gymnosperms 1. Seed plants that produce seeds in cones. 2. Have a vascular system. 3. Examples include conifers, cycads, and ginkgos.

8. D. Angiosperms (flowering plants) 1. Produce flowers -reproductive structure that produces fruits and seeds. a. Attract birds, animals, and insects to carry pollen. b. Reproductive parts called stamen (male part produces pollen) and pistil (female part produces ovules) 2. Produce seeds enclosed within a structure called a fruit. a. provide food, protect the seed, and help disperse the seed. b. Seeds contain a supply of stored food called the endosperm.

9. 3. Classified into two groups: a. Monocots -Produce seeds with only 1 seed leaf (cotyledon) -Flower parts in multiples of 3’s -leaves have parallel veins -crocus, corn, grass b. Dicots -produce seeds with 2 seed leaves -flower parts in multiples of 4’s or 5’s -leaves with branching veins -roses, apples, beans

11. IV. Plants in Our Lives A. All plant parts-roots, stems, leaves, flowers, and fruit provide food. B. Wood for paper, lumber and fuel C. Medicines D. Plant fibers make paper, cloth, and rope