Plant Systems

1. Background Image http://www.respect-texas.org/bluebonnets.jpg Plant Systems • The Texas Bluebonnet (Lupinustexensis) is our state flower and a plant native to Texas. • Remember that plants are NOT dead, but very much alive and composed of eukaryotic cells! • In this unit we will discuss the systems in plants, specifically transport, reproduction, and response.

2. Review of Plant Cells • Plants are multicellular eukaryotes w/ cell walls made of cellulose. • Plants are autotrophs that carryout photosynthesis to obtain energy. • To carry out cellular functions, plants need: • Sunlight • Water • CO2 • Minerals http://www.terrebonneonline.com/plantcell1.jpg

3. Review of Photosynthesis 6CO2 + 6H20 + LIGHT C6H1206 + 602 (Carbon dioxide) (water) (glucose) (oxygen) • Photosynthesis – the process by which plants convert light energy and carbon dioxide into sugars as a food source for the plant. http://s2.hubimg.com/u/701793_f520.jpg

7. The Second Part of Photosynthesis • Calvin Cycle or Light Independent Reaction • • Also called Carbon Fixation or C3 Pathway • • Uses energy (ATP and NADPH) from light reaction to make sugar (glucose). • Occurs in the Thylakoid membranes

12. Cell Specialization • Plants have cell specialization (different cell types perform specific functions). • EX Root cells, stem cells, and flower petal cells all have specific functions (jobs) that they carry out for the plant. http://www.bio.txstate.edu/~wetlands/Kids_and_Teens_Page/parts%20of%20a%20plant.jpg

13. 3 TYPES OF PLANT TISSUES DERMAL – PROTECTION FOR THE PLANT (WAXY COATING) VASCULAR – TRANSPORT FOOD & WATER GROUND TISSUE – Cells that lie between dermal and vascular tissue make up the ground tissue. CONTAINS CELLS THAT ARE THE SITE OF PHOTOSYNTHESIS

14. Veins in a plant are called VASCULAR TISSUE There are 2 types of Vascular Tissue: 1. Xylem – transports water from roots to the rest of the plant 2. Phloem – transports sugars and other nutrients throughout a plant (FOOD)

15. MERISTEMATIC TISSUE Undifferentiated – has not yet become specialized These cells are produced in the apical meristems (tips of roots & stems) Meristematic tissue is the only plant tissue that produces new cells by mitosis!

18. Specialized Tissues - Leaves • Leaf is the organ wheremost photosynthesis, and transpiration [evaporation from plants] occurs. • Remember, photosynthesis is used by plants to create energy. • Through the leaf run veins transport water, sugars, and minerals to the plant cells. http://www.ecomagic.org/fruition/leaves-1.jpg

19. Leaves Stomata are pores or holes in the epidermis of the leaf that allow gas exchange (stoma – singular) Carbon dioxide comes in through the stomata and oxygen leaves through the stomata

20. Guard cells on each side of the stomata control its opening and closing Water is also lost through the stomata in a process called transpiration, so plants only leave stomata open long enough to do photosynthesis

21. When water pressure within the guard cells is high (lots of water inside of plant) the thick outer walls of the cells are forced into a curved shape, which opens the stoma. • When water pressure within the guard cells is low the inner walls pull together and close the stoma.

22. Stoma & Guard Cells

24. Specialized Tissues - Stems • Stems are specialized cells that support leaves to hold them up to sunandtransport water, sugars, and nutrients through the plant. • Some stems are also modified for sugar [glucose] storage areas. http://www.arboretum.fullerton.edu/grow/images/plant_organs.jpg

26. In most plants, stems contain distinct nodes, where leaves are attached, and internodes regions between the nodes.

27. Monocot – scattered vascular bundles • Dicot – vascular bundles arranged in a ring

28. Secondary Growth of Stems • Takes place in lateral meristematic tissues called • Vascular cambium – produces vascular tissues and increases stems thickness (wood) • Cork cambium – makes the outer covering (bark)

29. Specialized Tissues - Roots • Rootsareunderground organs that absorb water and minerals necessary for transport in the plant andanchor [hold] the plant in the soil. • They help to prevent soil erosion. http://www.kidsgardening.com/onlinecourse/Diagrams/c5/c5-1root.gif

30. PARTS OF A PLANT ROOTS – ABSORB WATER AND NUTRIENTS AND ANCHOR THE PLANT TO THE GROUND TWO TYPES OF ROOTS: FIBROUS (Clump of short, threadlike roots) TAPROOT (Single, large central root)

32. Transport Tissues • Just like in animals, vascular [vein] tissue is the transport system for the plant. • Xylem – transports water (W X Y Z for w=water, xy=spelling xylem and z=the way the word sounds) in stacked cells to form tube like drinking straws; movement is UP from roots to leaves • Phloem – transports sugar/food; movement can be up and down http://3.bp.blogspot.com/_b8o0_bDa4QI/RsKvBY5ZufI/AAAAAAAAAF0/BmCafNOYe6A/s400/xylem1%5B1%5D.gif

33. Alternation of Generations • Diploid (2n) • Haploid (1n)

34. Reproductive Tissues - Flowers • Flowersare a reproductive organ (but not all plants have flowers). • They havemale and female parts. • pollination – transporting pollen (sperm) from the male to female parts (ovule) • fertilization – union of sperm with egg (creates a plant embryo [seed] which grows into a mature plant). http://www.prairiefrontier.com/pages/families/flwrparts.jpg

35. Flower Parts • Male • Stamen – consist of the anther (produces pollen) and filament (supports anther) • Pollen – contains sperm • Female • Pistil – consist of the stigma (where pollen lands), style (connects stigma to ovary) and the ovule (develops into the fruit) • Ovule – develops into an egg, eventually becomes the seeds when fertilized • Non-sexual • Petals – colored parts, attract pollinators (EX bees) • Sepals – green parts, protect flower parts

36. Flower Parts Cont. http://www.microscopy-uk.org.uk/mag/artoct08/bj-peru.html

37. Reproductive Tissues - Seeds • A seed consists of an embryo surrounded by a food source. • Seeds are encased in a protective covering called a seed coat. • EX fleshy fruit such as strawberries, apple, tomato, peach, cucumber • EX dry fruit such as walnuts and acorns http://asm.wku.edu/courses/Biol115/Wyatt/Plants/seeds/seed.gif http://urbanext.illinois.edu/gpe/images_rev/seed-pics.jpg

38. Seedless Reproduction • Seedless plants do not form hard seeds (EX mosses and ferns) they produce spores and therefore MUST have water for the sperm to swim to the egg. http://biology.uwsp.edu/courses/plantid/cp-seedless/images/cp-seedless-images-sm/013-d.lg.sm.jpg http://www.kidsgardening.com/onlinecourse/Diagrams/c10/c10-4fern.gif

39. Response • Just like animals, plants respond to changes in their environments (called tropism). • There are four main types of tropisms: • Gravitropism/Geotropism = response in plants that make it grow either with the pull of gravity or against it • Hydrotropism = response in plants that bends it towards water • Phototropism = response in plants that bends it towards light • Thigmotropism = response in plants that bends it around an object (EX a vine wrapping around an arbor)

40. Response Cont. http://withfriendship.com/images/h/38808/Tropism-picture.gif

41. Response Cont. • Another type of response, specifically to changes in pressure, is called a nastic response. • The most common example is the infamous Venus flytrap which closes its leaf when the plant senses an insect through changes in cell pressure. • North Carolina’s Nastic Slideshow http://www.justvenusflytraps.com/images/homepageimage.jpg

42. PLANT KINGDOM

43. Conclusion • Plantsprovide consumers with oxygen to breathe, food, shelter, as well as cleaning the air and water for the planet. This photo was taken in the Scottish Highlands. • Just like animals, plants are active responders within various environments to survive and thrive. • Their use and importance is numerous; humans use plants with healing properties in medical treatments. Photographby Luis del Río