Transcript Plants
Interest Grabber •Plants Make the World Go Round •Life as we know it today could not exist without plants. Plants provide us with many essential items other than food. 1.With your partner, list five items you use daily that are byproducts of plants. 2.With your partner, list three items that plants must get from animals—either directly or indirectly. Gymnosperms vs. Angiosperms Comparing Features of Seed Plants Feature Gymnosperms Angiosperms Seeds Bear their seeds on cones Bear their seeds within flowers Reproduction Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination Examples Conifers, cycads, ginkgoes, gnetophytes Grasses, flowering trees and shrubs, wildflowers, cultivated flowers Plants are categorized as Annuals Biennials Perennials that complete their life cycle in that complete their life cycle in that complete their life cycle in 1 growing season 2 years More than 2 years The 5 Main Parts of a Plant Buck Wheat Stems- 2 Types of Growth • Primary Growth Apical meristems located at the tips of shoots and roots produce primary growth. The tissues that result from primary growth are known as primary tissues. • Secondary Growth Secondary growth increases a plant’s stem and root width. In woody stems, secondary growth is produced by the cork cambium and vascular cambium, two meristems near the outside of the stem. The Vascular Plant Body Vascular Tissues •Vascular Tissues Vascular tissue conducts water, minerals, and organic compounds throughout the plant. •Xylem Xylem contains vessels, which are made up of cells that conduct water only after they lose their cytoplasm. Water flows between cells through pits and perforations in their cell walls. •Phloem Phloem contains sieve tubes, which are made up of cells that are still living. Substances pass between the cells through pores. Root Structure The Internal Structure of a Leaf Cuticle Veins Epidermis Palisade mesophyll Phloem Vein Xylem Spongy mesophyll Epidermis Stoma Guard cells Transport in Plants Movement of Water •Transpiration: Transpiration, the loss of water from a plant’s leaves, creates a pull that draws water up through xylem from roots to leaves. •Guard Cells and Transpiration: Guard cells control water loss by closing a plant’s stomata when water is scarce. Thus, they also regulate the rate of transpiration. Function of Guard Cells Guard cells Guard cells Inner cell wall Inner cell wall Stoma Stoma Open Stoma Closed Tropisms: the response of plants to external stimuli •Controlled by hormones called “auxins” •Control plant growth and development •Control plant response to environment •Stimulate cell elongation Photoperiodism and Flowering Responsible for the timing of seasonal activities such as flowering and growth. Short-Day Plant Midnight Noon Long Day Midnight Noon Short Day Midnight Noon Interrupted Night Long-Day Plant The Structure of a Flower Stamen Anther Filament Ovule Stigma Style Carpel Ovary Petal Sepal Comparing Wind-pollinated and Animal-pollinated Plants Characteristics Wind-pollinated Plants Animal-pollinated Plants Pollination method Wind pollination Vector pollination Relative efficiency of pollination method Less efficient More efficient Plant types Mostly gymnosperms and Angiosperms some angiosperms Reproductive organs Cones Flowers Adaptations that promote pollination Pollination drop Bright colors, sweet nectar Comparison of Monocot to Dicot plant parts Monocots Dicots Seeds Single cotyledon Two cotyledons Leaves Parallel veins Branched veins Flowers Floral parts often in multiples of 3 Floral parts often in multiples of 4 or 5 Stems Vascular bundles scattered throughout stem Vascular bundles arranged in a ring Roots Fibrous roots Taproot