Transcript Document
Plant Cell Plants are: Eukaryotic Autotrophic Multicellular Cell walls of cellulose Vocabulary: - vascular – refers to an internal system of tubes or vessels to transport materials throughout the plant; basis or first major division of plants into bryophytes and tracheophytes; includes: - xylem – transports water and minerals up from the roots to the shoots - phloem – transports sugar (food) down from the leaves to the rest of the plant Xylem brings water up from the roots to the shoots Phloem carries sugar (food) down from leaves throughout the plant Bryophytes – nonvascular plants Examples include: 20 mm Liverworts Hornwort Moss Bryophytes – nonvascular plants - economically important Ex) sphagnum moss – also called peat or peat moss Grows in boggy areas called peat bogs; extremely absorbant; used in agriculture/horticulture Seed dispersal by edible fruit, by wind, as well as other means. The picture to the right is of a samara from a maple tree. Vocabulary Seed – adaptation to terrestrial life composed of a plant embryo, stored food, and a protective coat Which is a monocot and which is a dicot? How do you know? Tracheophytes – vascular plants •Seedless plants –whiskferns, horsetails, and ferns Whisk fern horsetail fern Seedless vascular plants: Ferns - reproduce with spores - diagram shows spores growing in clusters called sori on the back of the frond of the fern Seedless vascular plants dominated during the Carboniferous period. Vocabulary Cone – reproductive structure of gymnosperms; contains pollen in males and ovules in females Flower – reproductive structure of angiosperms composed of 4 sets of modified leaves Fruit – mature ovary of a flower that protects dormant seeds and aids in their dispersal Ovulate cone from a pinetree (female) Staminate cone from a pinetree (male) Tracheophytes – vascular plants cont. •Seed plants •Gymnosperms – have seeds in cones; include: ginkgos, cycads, gnetophytes, and conifers Ginkgo Cycad Welwitschia Gnetum Ephedra Gymnosperms called gnetophytes; only 3 extant species Conifers: top row: Douglas fir, Sequoia, Cypress; bottom row: juniper, Australian pine tree; not shown: yew, spruce, other pines Tracheophytes – vascular plants cont * Seed plants •Angiosperms – flowering plants - have flowers, fruits, and seeds Grasses are flowering plants, too. So are trees. Grass flowers Flower (male) pistil (female) http://plantsinmotion.bio.indiana.edu/plantmotion/flowers/star lily/star.html Ovaries with ovules become fruits with seeds after the ovule (egg) is fertilized by sperm from the pollen Pollen grains contain sperm. They are produced in the anthers of the flowers in angiosperms. Pollination - by many vectors, including: Wind Water Animals Fruit or Veggie Humans eat lots of different plant parts. A fruit is the ripened ovary and contains seeds. Therefore, tomatoes, peppers, squash, olives, and cucumbers are fruits, not vegetables. Vegetables – the vegetative parts of the plants that we eat. Includes: •Roots – carrots, turnips,radishes •Stems – celery, bok choi, rhubarb, garlic, broccoli, onions, potatoes •Leaves – lettuce, cabbage, parsley Other plant parts that we eat: Seeds – pinto beans, peas, sunflower seeds, corn, pepper corns, rice, pecans, coconut Flowers – anise flowers (licorice), basil; http://homecooking.about.com/library/weekly/blflowers.htm Good rule of thumb: if you didn’t get it at the store, DON’T EAT IT! We don’t just eat plants, we also wear them, build with them, and use them for medicines! Plant Structure & Function Each plant part - root, stem, leaf - has a specific role in keeping the plant alive through photosynthesis Each plant part - root, stem, leaf - has a specific role in keeping the plant alive through photosynthesis. Write the equation for photosynthesis: 6 CO2 + 6 H2O -------sunlight---------- C6H12O6 + 6 O2 Carbon dioxide + water in the presence of sunlight yields glucose + oxygen Remember, this takes place in the chloroplasts inside the plant cells. Monocots & Dicots Cotyledons – nonphotosynthetic leaves of an immature plant; provide source of nutrients until plant can produce its own food Leaves - site of photosynthesis - cross section - epidermis – adaptation for terrestrial life - waxy cuticle - stomata - transpiration Leaf Leaf structure supports its function as the primary organ for photosynthesis Leaves - composed of blade, veins, petiole - simple or compound (see identifying leaves ppt) - pinnately or palmately compound - alternate or opposite if compound - pinnate or palmate venation Overview of movement of photosynthesis reactants and products through a plant Stems Support and transport Contains xylem and phloem Modified: Strawberry runners potatoes onion Stems Define plant type: herbaceous, shrub, vine, tree Herbaceous plant shrub vine Stems – cross sections through a dicot and a monocot Roots Function – absorption, storage, anchorage Root hairs – extensions of the epidermis that increase absorption by increasing surface area; see photo Fibrous roots – see monocot information Tap roots – see dicot information Root Structure Nitrogen fixation – occurs in the roots and in the soil around the roots of plants; performed by bacteria Plants that live in nitrogen poor soils trap and break down insects with enzymes to obtain nitrogen Venus fly trap Pitcher plant Vocabulary Primary growth – increase in length; stems get longer, roots grow deeper Meristem – tissue that is growing Apical meristem – tissue found at the tips of roots and stems that is actively dividing/growing Plant Responses Plant responses are called tropisms. Tropisms can be positive or negative. They include phototropism, gravitropism, and thigmotropism. Most plant responses involve the action of hormones, including gibberellins, auxins, and ethylene. Plant Responses Effect of gibberellens on Thompson’s seedless grapes and on growth in a dwarf plant Auxins make plants bushier by making more branches at nodes when the apical meristem is cut off (the tips of the existing branches) Positive Phototropism http://plantsinmotion.bio.indiana.edu/plantmotion/movements/tr opism/phototropism/corn/cornworship.html http://plantsinmotion.bio.indiana.edu/plantmotion/movements/trop ism/solartrack/solartrack.html Effect of ethylene on the ripening of an apple. NEGATIVE Gravitropism in Stems http://plantsinmotion.bio.indiana.edu/plantmoti on/movements/tropism/gravitropism/gravi1/gravi trop.html POSITIVE Gravitropism in roots http://plantsinmotion.bio.indiana.edu/plantmotion/move ments/tropism/gravitropism/rootgrav/graviroot.html Vines Illustrate Positive Thigmotropism