1. 1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. *See PowerPoint Lecture Outline for a complete, ready-made presentation integrating art and lecture notes. Introductory Plant Biology Ninth Edition Kingsley Stern Chapter 4 Image Slides*

2. Botany Chapter 4 Tissues

3. 3 Overview §4 organs of plants 1. Roots 2. Stems 3. Leaves 4. Flowers All formed from tissues

4. 4 Meristematic Tissue §Meristematic tissue/meristems- permanent regions of growth in plants; 3 Types of Meristems 1. Apical meristem- found at or near the tips of roots and shoots - increases the length of plant; this is primary growth

5. 5 Meristems cont. 2. Lateral meristems- produce tissues that increase the girth of roots and stems; secondary growth 2 types of lateral meristems 1. Vascular cambium/ cambium- produces secondary tissues; xylem and phloem

6. 6 Meristems cont. -a thin cylinder of brick-shaped cells that extends through root and stems 2. Cork cambium-produces bark - lies just inside the outer bark - thin cylinder of cells that runs length of roots and stems

7. 7 Meristems cont. 3. Intercalary meristems- found at nodes in grasses and related plants instead of vascular and cork cambium - node- point of leaf attachment - develop at intervals along stems - also add to stem length

8. 8 Fig. 4.1

9. 9 Tissues produced by meristems §3 Types of Simple Tissues 1. Parenchyma tissue- made of parenchyma cells; most abundant - Cells generally have 14 sides and large vacuoles

10. 10 Parenchyma cont. - may contain numerous chloroplasts (referred to as chlorenchyma) - w/out chloroplast, function in food and water storage - can multiply and repair wounds and form roots on a cutting

11. 11 Simple tissues cont. 2. Collenchyma tissue- made of collenchyma cells - found beneath epidermis - provide flexible support - “strings” of celery

12. 12 3 Simple tissues cont. 3. Sclerenchyma tissue - made of sclerenchyma cells - thick, tough, secondary walls with lignin (a polymer) - most are dead at maturity and function in support

13. 13 2 Types of sclerenchyma tissue 1. Sclereids or stone cells- produce gritty texture of pears and hardness of shells and peach pits 2. Fibers- used to manufacture textile goods, ropes, string, canvas

14. 14 Complex tissues-2 or more types of cells 1. Xylem- plumbing and storage systems - chief conducting tissue throughout all organs for water and minerals absorbed by roots

15. 15 Xylem cont. - consists of parenchyma cells, fibers, vessels, tracheids and ray cells - vessels- made of dead cells called vessel elements; straw-like with bars of wall material across open areas

16. 16 Xylem cont. - tracheids- dead cells with thick cell walls - no vessel-like openings, but have pits which allow water to pass from cell to cell -rays-long-lived parenchyma cells produced in horizontal rows; conduct water laterally

17. 17 Fig. 4.6

18. 18 Complex tissues cont. 2. Phloem- conducts food produced by photosynthesis throughout the plant - made of 2 types of cells 1. Sieve tube members- cells layed end to end forming sieve tubes

19. 19 Complex tissue cont. 1. Sieve tube members cont. - Walls are full of small pores through which cytoplasm extends cell to cells - sieve plates porous regions of sieve tube members

20. 20 Complex tissues cont. 2. Companion cells - help control transport of sugar through sieve tube member

21. 21 Complex tissues cont. 3. Epidermis- outermost layer of cells of all young plants - one cell thick - cuticle- protective layer on the surface of the outer wall - made of fatty cutin

22. 22 Complex tissues cont. Epidermis cont. -stomata- (sing. Stoma)- pores in leaves -guard cells- cells that border stoma

23. 23 Complex tissues cont. 4. Periderm- consists of outer bark (woody plants) -made of cork cells- dead at maturity - Suberin- fatty substance secreted by cork cells that waterproofs and protects the plant

24. 24 Complex tissues cont. Periderm cont. -lenticels- pockets of parenchyma cells with no suberin (pg. 63) - function in gas exchange between air and interior of the stem

25. 25 Secretory Cells and Tissues Examples of secretions: §nectar in flowers §oils in citrus fruits and mint §resins in pine trees §opium

26. 26 Fig. 4.7

27. 27 Fig. 4.8

28. 28 Fig. 4.10

29. 29

30. 30 Fig. 4.11

31. 31 Fig. 4.14