Parts of the plant and their functions

1. Parts of the plant and their functions

2. Importance of plants • Without plants life on earth would not exist

3. Plants: • Primary source of food for people and animals • Produce oxygen • help to keep us cool • renew the air

4. Plants: • slow wind speed • provide a home for wildlife • beautify surroundings • perfume the air • furnish building materials and fuel

5. Parts of a plant • Four basic parts • leaves • stems • roots • flowers

6. Leaves • the food factory of the plant • produce the food used by the plant or stored for later use

7. Shape and size of leaves • vary among plants • used for identification of plants

8. Leaf arrangement • alternate • opposite • whorled • arranged in a circle around the stem

9. External leaf structure • petiole - leaf stalk • leaf blade (leaf) • has veins • forms structural framework of the leaf

10. Midrib • large center vein from which all other leaf veins extend

11. Margins • edges of leaves • assists in plant identification

12. Internal leaf structure • epidermis • skin of the leaf • single layer of cells • protects leaf from loss of too much moisture

13. Guard Cells • open and close the small pore on the underside of the leaf

14. Stomates • allow the plant to breathe and transpire • give off moisture

15. Chloroplasts • contain chlorophyll • located inside the food making cells

16. Photosynthesis • process by which CO2 and H2O in the presence of light are converted to sugar and oxygen

17. Chemical formula • 6CO2 + 6H2O • -----> in reaction with sunlight and chlorophyll ------> • C6H12O6 (glucose) + 6O2

18. food • manufactured in the leaves moves downward through the stem to the roots • used by the plant • stored in stem or root and leaf in the form of sugar, starch or protein.

19. Respiration • plants respire 24 hours a day • consume O2 and give off CO2 • plants produce more O2 through ps. Than they consume during respiration and growth.

20. Stems • have two main functions • movement of water and minerals from the roots upward and movement of manufactured food down

21. Stem functions • support of leaves and reproductive structures

22. Stems also • used for food storage and reproduction of plants involving cuttings • Green stems manufacture food just as leaves do

23. External Stem Structure • lenticels- breathing pores • bud scale scars-indicate where terminal bud has been located previous year.

24. Leaf Scars • shows where leaf was attached • Distance between the two represents one year of growth.

25. Internal Stem Structure • phloem- bark, carries manufactured foods down. • Xylem- wood, carries water and minerals up. • Cambium- separates the 2 and produces all new cells. • Characteristic of dicots

26. Internal Stem Structure • dicot- dicotyledon, a plant with 2 seed leaves

27. Monocot • Monocotyledon - a plant with one seed leaf. • Have vascular bundles, contain both xylem and phloem in each small bundle

28. Monocot • stems have no cambium • cells enlarge to create size of mature stem

29. Economic Importance • food • building materials

30. Roots • Usually underground • functions: • anchor plant and hold upright • absorb water and minerals form soil and conduct to stem • store food, & propagation

31. Root Structure • internal • similar to stems • older roots have xylem, phloem and cambian

32. external • root cap • produces continuous supply of new cells • protects roots as they push through soil

33. Structure • root hairs • absorb moisture and minerals • small roots

34. Functions other than water and mineral absorption • cash crops for food • carrots • beets • radishes • sweet potatoes • propagation

35. Type of root systems • fibrous-grasses • easier transplanting • shorter, smaller, more compact • lap root-carrot • longer and fewer roots

36. Flowers, Fruits, and Seeds • pollination- color of flower attracts insects to fertilize flower • beginning of fruit and seed formation • fruits and seed are attractive to birds who eat and spread seeds. • Reproduces plant • some seeds carried on animals coats

37. Parts of the Flower • differ in size, shape, and color, some basic parts • sepal • green leaf-like part, covers and protects bud before opening

38. Petals • are actually leaves • usually bright colors to attract pollinating insects.

39. Parts of the Flower • stamens • male part of flower • has two parts • filament-stalk

40. Anther • anther- sac-like structure on top of filament, contains pollen

41. Parts of the Flower • Pistil - female part • in the center of flower • has three parts

42. Pistil • three parts • stigma - top - sticky • style - tube leading from stigma to ovary

43. Ovary • egg cells develop here • grows to become fruit or seedcoat

44. Types of Flowers • complete • contains 4 main parts

45. Incomplete • does not have all 4 main parts

46. Perfect • has stamens and pistils

47. Imperfect • lacks stamens or pistils

48. Types of Flowers • monoecious • stamens and pistils are found in separate flowers on the same plant • ex: Corn

49. dioecious • male or staminate flowers found on one plant, female or pistilate flowers on another plant • ex: holly