4What is a plant?Plants are multicellular eukaryotes that have cell walls made of cellulose.They carry out photosynthesis using the green pigment chlorophyll.Plants include trees, shrubs, grasses, mosses, flowers and ferns.
5Overview Flowering plants make up almost 90% of all plant species. We will study the 4 main divisions:1) Non-Vascular PlantsSeedless Vascular PlantsGymnosperms4) Angiosperm
7Non-Vascular Plants generally small, low to the ground live on land in moist, shaded habitatslack vascular tissuelack true roots, leaves and stemswater required for reproduction(do not form seeds)Ex. Mosses, Liverworts, Hornworts
8Mosses Phylum Bryophyta Many mosses can tolerate low temperatures, and grow abundantly in swamps and bogs."Leaves" are only one cell thick, so they lose water quickly if the air is dry.They do not have true roots, but have rhizoids, which are long, thin cells that anchor them in the ground.
9Liverworts Phylum Hepaticophyta Some species resemble the shape of a liver.Flat leaf-like structures very close to the ground.Can reproduce sexually and asexually.
10Hornworts Phylum Anthocerophyta Generally found in soil that is moist year-round.Look very similar to Liverworts.During part of their life cycle, they look like a tiny green horn.
11Read and Respond Read pages 556-559 in textbook Answer questions #1, 2, 4on page 559.
12Warm-Up! What are the four division of plants? Plants contain ________ in their chloroplasts.Plant’s cell walls contain ___________.
13Seedless Vascular Plants Vascular tissue: a type of plant tissue specialized to conduct water and nutrients through the plantXylem - carries water upward from the rootsPhloem - transports solutions of nutrients and carbohydratesCan move fluids through the plant body, even against the force of gravity.Remember: Xylem=Skylem
14Seedless Vascular Plants Lignin makes the cell wall rigid, and together with the transport system, allows plants to reach great heights.Seedless vascular plants include club mosses, horsetails and ferns.Have true roots, leaves and stems.
15Seedless Vascular Plants Roots are underground organs that absorb water and minerals.Leaves are photosynthetic organs that contain one or more bundles of vascular tissue. This vascular tissue is gathered into veins made of xylem and phloem.Stems are supporting structures that connect roots and leaves, carrying water and nutrients between them.
16Club Mosses Club mosses are small plants that live in moist woodlands. Members of the genus Lycopodium (common club moss) look like miniature pine trees.
17HorsetailsNon-photosynthetic, scale-like leaves are arranged in distinctive whorls at joints along the stem.Contain crystals of abrasive silica.Horsetails were commonly used to scour pots and pans.
18FernsHave true vascular tissues, strong roots, creeping or underground stems called rhizomes and large leaves called fronds.Can thrive in areas with little light; most abundant in wet habitats.
19PracticeRead pagesAnswer questions 1,2,5 on page 563
20Warm-Up! Which of the following is not a characteristic of plants? EukaryoticCell walls contain chitinMulticellularContains chloroplastsThe leaves of ferns are called?SoriRhizomesFrondsSporesWater is carried up through the roots to every part in the plant by:Cells wallsCuticlePhloemXylem
21Seed Plants Two groups of seed plants: GymnospermsAngiospermsGymnosperms ("naked seed") bear their seeds directlyon the surfaces of cones; includes conifers, palm-like plants.Angiosperms ("enclosed seed") bear their seeds in a protective layer of tissue; grasses, flowering trees and shrubs, all species of flowers.
22Seed Plants Cones: seed-bearing structures of gymnosperms Flowers: seed-bearing structures of angiospermsPollen grain: sperm-producing part of the plantPollen is carried to the female reproductive structure by wind, insects, or small animals.
23Seed PlantsA seed is an embryo that is encased in a protective covering, and surrounded by a food supply.An embryo is the early stage of plant development.Special adaptations that help them to disperse:e.g. textured to stick in fur; "wings"; fruits that are eaten
24GymnospermsGymnosperms include gnetophytes, cycads, ginkgoes and conifers.
25ConifersMost common gymnosperms; includes pines, spruces, firs, cedars, redwoods, junipers, etc.Thrive in a wide variety of habitats.Leaves are long, thin needles - reduces evaporation.Most are "evergreens" - retain leaves throughout the year.
27AngiospermsAngiosperms develop unique reproductive organs known as flowers.Evolutionary advantage - attract animals which then transport pollen (more efficient).Flowers contain ovaries, which surround and protect the seeds.
29AngiospermsAfter pollination, the ovary develops into a fruit, which protects the seed and helps it disperse.Fruit - wall of tissue surrounding the seed; attracts animals, which digest and spread the seed.
30Monocots and DicotsMonocots and dicots are named for the number of seed leaves, or cotyledons, in the plant embryo.Monocots = one seed leaf (corn, wheat, lilies, orchids)Dicots = two seed leaves (roses, clover, tomatoes, oaks, daisies)Cotyledon: the first leaf or pair of leaves produced by the embryo.