Introduction to Plants

1. Introduction to Plants Mrs. Foster

2. Earliest Plants • Algae • Phytoplankton • Lived in the sea

3. Problem Drying Out Making Food Reproduction Gravity & Support Getting water & nutrients Solution Waxy cuticle, stomata Formed leaves Develops spores & seeds Bark (cork) & vessels Roots & vessels Problems with life on land

4. Plant Characteristics • Multicellular • Eukaryotic • Photosynthetic 6CO2 + 6H20 + radiant energy C6H12O6 (glucose) + 6O2. • Have cell walls made of Cellulose. • Not all plants have vascular tissue so they are divided into different phyla

5. Types of Plants • Nonvascular(Bryophytes) • Does not have vascular tissue or true roots leaves, or stems. • nonseed plants • Vascular (Tracheophyta) • vessels for transport and support • Have roots, stem, leaves, xylem, and phloem

6. TRACHEOPHYTES Without seeds With seeds

7. Nonvascular:The Bryophytes • Must grow in moist environments • Mosses, Liverworts, Hornworts • AVASCULAR = very small • Liverworts were the first land plants • 500 m.y.a. • Used for fuel (peat)

8. Liverwort / Moss

9. Non-seed Vascular:The Pteridophytes • Club Mosses (Lycophyta) - Leaves produce spores • Horsetails (Arthrophyta) • Jointed stems • Reproduction similar to club moss • Ferns (Pterophyta) • 400 m.y.a.

10. Seed Vascular:The Spermatphytes • Cycads, Ginkgo Biloba, Gnetophyta, Conifers, Anthophyta • 360 million yrs ago during the Paleozoic Era. • Conifers= 250 million yrs ago • seeds surrounded by a fruit or carried on scales of a cone. • Can grow in a wide variety of habitats.

11. Vascular Plants • Vascular tissue that transports food and water • Vascular refers to veins • Vessels • XYLEM = transports water & dissolved minerals from roots to leaves • PHLOEM = transports sugars from leaves to rest of plant • Spores or seeds for reproduction

12. Seedless Vascular Plants • have vascular system, but do not produce seeds or flowers • ex: fern • Leaves= fronds • Produce spores • 3 divisions • Lycophyta – club mosses • Arthrophyta- horsetails • Pterophyta- ferns

13. Why Make Seeds? • Has own food supply • Protective coat against harsh conditions • Some are designed for travel to new areas

14. Vascular Seed Plants • Seed—protective structure where embryonic plant can be stored until conditions are favorable for growth. • Two types of seed plants • Gymnosperms (4 phyla) • Angiosperms (1 large phylum)

15. Gymnosperms • Gymno = “naked” Sperm = “seed” • First plants to produce seeds • No flowers, No fruit • Seeds are not protected by a fruit • Examples: • Ginkgo biloba • Conifers—plants with seeds inside cones and needle-like leaves • Pines, firs, cedars, redwoods

16. Coniferophyta (largest group of gymnosperms) • Needle or scale-like leaves • Bear seeds in woody cones • Can live in very cold climates • Most are evergreens • Have wood • Made of thick-walled vessels

17. Angiosperms • Angio – “flower” Sperm – “seed” • Extremely diverse • All have seeds enclosed in fruit • Produce fruits with 1 or more seeds • Fruit is the ripened ovary of flower • Fruit aid in seed dispersal • Examples: maple trees, apple trees, wildflowers, herbs, azaleas, grass, oak trees, poplar trees

18. Flowers • Pistils = female reproductive structures • Stamens = male reproductive structures • Complete flowers • Have petals & sepals • Have male and female parts • Incomplete flowers = missing one or more parts

19. Two types of Angiosperms • Monocot • Ex: corn, grass • Dicot • Ex. trees, shrubs, sunflowers , most flowers

20. Monocots mono = “one” cot = “seed leaf” Approx. 60,000 species Flowers = multiples of 3 Leaf veins parallel Dicots di = “two” cot = “seed leaf” Approx. 170,000 species Flowers = multiples of 4 or 5 Leaf veins branching Types of Angiosperms