Chapter 8

1. Chapter 8 Plants

2. Section 1: The Plant Kingdom • Plants • Autotrophic Eukaryotes • Descendants of green algae • Live in water and land • Classifying plants:

3. LAND PLANTS must adapt for survival • Obtaining water and other nutrients • Retaining Water • Cuticle • waxy, waterproof layer, covers leaves • Transporting Materials • Water and minerals from bottom (soil) to top of plant • Food from top (sunlight) to bottom of plant • Vascular tissue • tube- like structures for transport • Support • Reproduction • Structures to transport and protect zygotes (fertilized egg)

4. Complex Life Cycles • Two stages (see page 255)

5. Section 2: Plants Without Seeds • Both Nonvascular +Vascular • Three major nonvascular groups: • MOSSES • 10, 000 species • “fuzzy” is gametophyte generation • Rhizoids • Thin roots that anchor moss and absorb water and nutrients • Sporophyte grows out of gametophyte • capsule at end contains spores

7. LIVERWORTS • 8,000 species • Grow as thick crust on moist rocks near water • Leaf-like gametophyte looks like human liver • Wort means “plant” • HORNWORTS • <100 species • Live in moist soil, mixed in with grass plants • Sporophytes look like horns

8. Seedless Vascular Plants • Reproduce by releasing spores • Three types: • Ferns: 12,000 species • Underground stems with roots growing down and leaves growing up • Leaves called FRONDS • Fronds have spores on their undersides • Horsetails • needle-like branches around stems • Club Mosses • Like tiny pine trees

9. Section 3: Characteristics of Seed Plants • Outnumber seedless 10:1 • Examples: • Food- rice, peas, squash • Clothes- cotton and flax • Building materials- oak, pine, maple • Produce majority of oxygen you breathe • Plant is Sporophyte • Gametophytes are microscopic

10. Seed plants (cont.) • Contain Vascular tissue • Two types: • Phloem- Food transport • Xylem- Water and mineral transport • Pollen • Delivers sperm to egg cells • Seeds • Protects young plant from drying out

11. More on Seeds…. • Partially developed plant inside all seeds • If seed lands in good conditions, plant sprouts and grows • STRUCTURE: • Embryo • Stored food • Cotyledons = seed leaves • Sometimes used for food storage • Seed Coats- “skin” • Peanuts and lima beans • Some seeds are surrounded by a FRUIT

12. Seed Dispersal • Scattering of seeds • Animal eats fruit  digestive system • Seeds “hook” onto animal fur or person’s clothes • Travel via water (rivers and streams) • Wind travel (dandelions) • Some plants “eject” their seeds

13. Germination • Occurs when embryo begins to grow again • Pushes out of seed • Must absorb water from environment • Roots grow down and stems and leaves grow up • Seedling = when plant’s leaves are present

14. Roots • FUNCTION: • Anchor plant in ground • Absorb minerals and water from soil • Store food • TYPES: • Fibrous Root System • Dense, tangled mess (pile of dirt when pulled) • Grass, corn, onions • Taproot System • One long, thick root • Carrots, dandelions

15. Roots (cont.) • STRUCTURE • Root Cap • Rounded tip prevents injury from rocks as it grows • Root Hairs • Grow out of surface and absorb water and minerals from soil • Anchor plant in soil • Vascular tissue • Located in center of root

16. Stems • FUNCTION • Transports substances between roots and leaves • Provides support and holds up leaves toward sun • STRUCTURE • Outer layer • Herbaceous (soft) vs. Woody (hard) • Cambium • Underneath bark of woody stems • Produces new phloem and xylem • Annual Rings • Made of xylem • Each band represents one year of growth

17. Leaves • FUNCTION • Capture sun’s energy and carry out photosynthesis • STRUCTURE • Stomata • Pores on surface that control gas exchange • Veins that contain Xylem and Phloem on inside • Contains chloroplasts (for photosynthesis) • TRANSPIRATION • Process by which leaves lose water via evaporation • Stomata closes to prevent water loss

18. Section 4: Gymnosperms and Angiosperms Gymnosperms • Seed plants • Produces “naked” seeds • -Not enclosed by a fruit • Needle-like or scale-like leaves • Deep-growing root systems • Split into 4 groups http://www.flickr.com/photos/odalaigh/2456681765/

19. Angiosperms • Seed plants • Flowering plants • Seeds are encased in protective fruits • Live everywhere from frozen Arctic to jungles to deserts and ocean’s edge http://www.flickr.com/photos/54178999@N02/5162360916/in/set-72157625304802716/

20. Four Groups of Gymnosperms • CYCADS • Found in tropical and subtropical regions • Look like palm trees with cones http://www.flickr.com/photos/brewbooks/244980266/in/photostream/

21. CONIFERS • Keep leaves or needles all year round • Pines, sequoias, junipers http://www.flickr.com/photos/mbgrigby/3905963867/

22. GINKGOES Only one species remains In cities and are resistant to air pollution http://www.flickr.com/photos/heather/70737617/

23. GNETOPHYTES-Found in deserts and rain forests-Trees, shrubs, and vines

24. Reproduction in Gymnosperms Cones- male and female Male cones produce tiny grains of pollen Female cones Contain OVULES that hold egg cells http://www.flickr.com/photos/jonathanvail/3357983607/

25. Reproduction in Gymnosperms • Four stages • Pollination- transfer of pollen to female cone (by wind) • Fertilization- joining of sperm and egg • Seed Development- can take up to 2 years to mature • Seed Dispersal- only a few seeds will grow into new plants

26. Angiosperms Flowers are necessary for reproduction STRUCTURE Sepals- protective green leaf structure Petals- colorful part of flower Stamens- male reproductive structure Filament- thin stalk Anther- produces sperm, at top of filament Pistils- female structure Stigma- sticky tip Style- slender tube Ovary- hollow structure at end of style Protects seeds as they develop http://www.flickr.com/photos/tuchodi/2620794341/

28. Reproduction of Angiosperms Pollinators ensure pollination Birds and bees are attracted to nectar Brush against anther, causing pollen to drop http://www.flickr.com/photos/jimmy-jay/4905633160/

29. Reproduction of Angiosperms Pollen travels down to ovary (fertilization) Ovary changes into a fruit to protect and aid in dispersal http://www.flickr.com/photos/oldonliner/3984587146/

30. Reproduction of Angiosperms

31. Types of Angiosperms

32. Make a Concept Map for the Plant Kingdom characteristics we’ve discussed….

33. Answer Key…..

34. Section 5: Plant Growth and Response Tropism Plant’s growth response toward or away from a stimulus Positive- toward a stimulus Negative- away from stimulus

35. Plant Growth and Response Three main stimuli Touch- coiling of vines Light- grow toward sun Gravity- roots go down (positive), leaves go up (negative) Hormones – chemicals that allow plant to respond EX: Auxin – speeds up growth and controls response to light http://www.flickr.com/photos/mouldfish/3753497440/

36. Seasonal Changes Photoperiodism Response to changes in length of night and day http://www.flickr.com/photos/davetbear/37247011/

37. Critical Night Length# of hours of dark that determines plant flowering • Short-day plants- flower when nights are longer than critical length http://www.flickr.com/photos/acetonic/4132307122/

38. Long-day plants- flower when nights are shorter than critical lengthDay-neutral plants- not sensitive to length of dark and night http://www.flickr.com/photos/johnkay/3364837884/

39. Seasonal Changes Dormancy Growth slows or stops For survival during cold weather and lack of liquid water

40. Life Span • Annuals • One season life cycle • Marigolds, wheat, cucumbers • Biennials • Two season life cycle • Parsley, celery, foxglove • Perennials • Live more than 2 years • Flower every year • Peonies, maple