Chapter 17

1. Chapter 17 Introduction to plants

2. Sec 17.1 • The structure of plants

3. 1. Leaf structures • Blade—flat, broad section that makes up largest part of most leaves, this is where photosynthesis takes place. • Veins—tubelike structures that carry water, minerals and sugar throughout the blade • Petiole—a short stalk that connets the leaf to the stem, usually where the vein enters the leave.

4. 2. Types of leafs A. Simple Leaves 1. Have just one blade B. Compound Leaves 1. Have two or blades, called leaflets, that are linked to one main petiole. a. Pinnate—like feathers, with smaller veins branching off a main central vein called the midrib. b. Palmate—resemble the fingers on your hand, with many lobes radiating from a central point. 2. Compound leaves have an advantage over simple leaves since have a larger surface area for photosythnesis to take place.

5. 3 types of leaves • Monocot • Veins are usually parallel • Dicot • Veins are usually branched • Needles • Look like needles

6. 4. Stems 1. Support leaves and flowers 2. Transport water and nutrients within the plant. 3. Transport in stems is accomplished by some tubelike cells that carry sugars from leaves to other parts of the plant. Some carry water and nutrients from the soil. 4. A potato is an underground stem that stores a large amount of food (starch). 5. The size of the plant depends on the size of the stem. 6. Growth begins in structures called buds, which may grow into leaves, branches or flowers.

7. Plants are grouped into one of four categories • Herbaceous Plant—Nonwoody, composed of relatively soft tissue covered with a thin protective layer. Stems vary in strength. • Shrub— Woody and strong stems, with a trunk diameter less than 3 inches and a mature height less than 13 ft. • Vine- have slender, woody stems that are usually supported by trees, post or other objects. • Tree-- Woody and strong stems, with a trunk diameter greater than 3 inches and a mature height greater than 13 ft.

8. Root • Portion of the plant that grows below the surface of the soil.

9. Root hairs • Tiny narrow tubes growing from the cell membranes of some root cells

10. Two common types of roots • Taproot • Single large central root with much smaller side roots branching out from it. • Carrot • Fibrous root • Shallow clump of short, threadlike roots. • Grasses

11. Flower Reproductive organ of a flowering plant Functions • Produce male gametes (sperm) • Produce female gametes (egg)

12. Pollen • Plant sperm • Can be transported by wind, water, insects or other organisms. • Plants produce large quantities of pollen to ensure pollination takes place.

13. Pollination Process of transporting pollen (sperm) from the male reproductive parts to the female reproductive parts.

14. Fertilization • The union of sperm with eggs to produce a zygote which develops into a plant embryo.

15. Seed Reproductive structure consisting of a plant embryo and its stored food.

16. Fruit In flowering plants, the seed develop in structure called a fruit. • Protects the seeds • Aids in seed dispersal.

17. Sec 17.2 Plants in the Biosphere

18. Ecological Roles • Plants make their own food • Use the sun’s energy to convert carbon dioxide and water into carbohydrates. (this is where they energy is stored) • Through photosynthesis plants give off oxygen.

19. Agriculture Humans have been growing plants for food for thousands of years. Plants account for a large portion of our diet ( ̴90%), either directly or indirectly.

20. Cereals • The edible fruits of seeds or grasses. • Rice • Wheat • Corn

21. 5 important agricultural plants • Potatoes • Wheat • Corn • Rice • Cassava—Plant found in Asia, Africa and south America where the roots are boiled, roasted or fried. Also can be made into flour or porridge.

22. Medicines Many medicines are extracted from plants. • Willow Bark is used to make aspirin. • Pacific Yew tree bark is being used to treat some cancers

23. Industry Many products made from plants. • Dyes • Glues • Perfumes • Car wax • Furniture polish • Clothing

24. Cellulose • A polysaccharide consisting of long chains of glucose molecule, that in the raw form has increased strength. • Cotton and flax plants are used to make fabric and ropes. • Wood can be used to build house, make furniture or ground up and turned into paper, burned and used as a fuel source.

25. Problem Plants Some plants are considered nuisance species or weeds. • Poison ivy—cause rashes • Rhubarb leaves are poisonous. • Weeds in gardens can steal nutrients and water from other wanted plants. • Tree roots can break sewage lines and septic tanks, can raise sidewalks.

26. Sec 17.3 Characteristics of Plants

27. Typical Plant • Multicellular • Eukaryotes • Cell wall • Autotrophic

28. Plant Cells • Have nucleus surrounded by cytoplasm • Membrane bound organelles • Contain chloroplast • Chlorophyll • Cell wall (made of cellulose) • Large Central Vacuole

29. Plant tissues Groups of cells that are similar in structure and are arranged so they perform a specialized function. Three types of plant tissue • Dermal • Vascular • Ground

30. Dermal Tissue • Protective or surface tissue that produces outermost tissue layer on leaves and stems. The dermal tissue protects the internal tissues of the plant, prevents water loss, and controls the gas exchange. • On Leaves it is the waxy coating. • On Stems it is the bark

31. Vascular tissue Transporting or conducting tissue

32. Xylem • Vascular tissue that transports water and minerals in a plant. • Made from dead cells

33. Phloem Vascular tissue that transports the sugars produced during photosynthesis throughout the plant.

34. Though xylem and phloem are both a part of the transportation system of plants, they transport different things. Xylem transports water and dissolved minerals. Phloem transports sugars throughout the plant.

35. Ground Tissue • Also called fundamental tissue • Perform photosynthesis, store organic material, and provide structural support.

36. The key difference between dermal tissue and ground tissue is that the dermal tissue creates the outer covering of a plant body while ground tissue creates most of the soft internal parts of the plant body.

37. Alternation of Generations • Plants switch from diploid generations to haploid generations. • Plants reproduce cells through mitosis, but create sex cells through meiosis.

38. Sec 17.4 Overview of Plant diversity

39. Size Plants very in size, they can be as small as moss or as large as giant redwood trees.

40. Vascular Plant A plant that has vascular tissue or characterized by the presence of conducting tissue. • Trees • Vines • Flowering plants

41. Nonvascular Plant A plant lacking vascular tissues, cannot get very large since there is no way to transport water and nutrients. • Mosses • Hornworts • Liverworts

42. Woodiness • Wood is a substance composed primarily of layers of xylem cells • Cellulose of the cell walls provide the structure • Woody plants • Trees • Shrubs • Vines

43. Reproduction • Plants are broke into to groups based on reproduction • Those that produce seeds (Gymnosperms and Angiosperms) • Those that do not produce seeds. (Ferns and Mosses)

44. Gymnosperm • A vascular plant that produces seeds enclosed in cones, seeds unprotected by an ovary or fruit.. • Pine trees • Firs • Spruces • Cypresses, • Redwoods

45. Gymnosperm reproduction • Male and Female cones • Male cones are small and produce pollen. • When the female is cone is ready to reproduce the scales open up and a sticky sap is produced. • Male pollen is released and carried by the wind and or gravity and gets stuck in the sap. • It then travels up into the cone and fertilizes the egg.

46. Angiosperm • A vascular plant that produces seeds enclosed in fruit, also referred to as flowering plants. • Apple trees • Strawberries • Wheat • Dandelions

47. Angiosperms have 3 unique Features: • Flowers • Fruits • Double Fertilization

49. Flower Structure • Reproductive shoots • Flower organs: • Sepal – leaflike, protect flower bud • Petal – modified leaves, attract pollinators • Stamen – ♂ reproductive organ • anther + filament • Carpel – ♀ reproductive organ • stigma + style + ovary • Flower attached to stem at receptacle • Pollination by wind, insects, birds