PLANT STRUCTURE AND FUNCTION

1. PLANT STRUCTURE AND FUNCTION

2. THE PHYLOGENY OF PLANTS… Charophytes (green algae) Bryophytes (non vascular) Trachoephytes (seedless, vascular) Gymnosperms (“naked seeds”,vascular) Angiosperms (contained seeds, vascular) Monocots / Dicots

4. Major Parts of a Plant • Leaves • Where photosynthesis occurs • Seeds • Method of sexual reproduction • Flower • Site where reproduction occurs • Stem • Transports nutrients and supports the plant • Root • take in nutrients and anchor plant

5. The Seed • Parts of a Seed • Cotyledon • The first leaves of a plant • Seed Coat • Outside covering of a seed • Endosperm • Food storage tissue that nourishes the embryo • Embryo • New plant developed after fertilization

6. Types of Seeds Monocots • A seed with only one cotyledon • All grasses are monocots • Flower parts in threes • Leaves with parallel primary veins Dicots • A seed with two cotyledons • Flower parts in fours or fives • Leaves with distinct vein network • All broadleaf plants are dicots

7. Plumule- is like a leave in its early development becomes the shoot Hypocotyl- develops into the stem Radicle- Becomes roots Seed Parts • Fertilizationzygoteseed (embryo)

9. Male Parts of the Flower Stamen- Makes up all male parts Pollen- Male sex cell, similar to sperm Anther- Sac-like structure on top of the filament Filament- Short stalk that holds the anther

10. Female Parts of the Flower Pistil- Makes up all female parts Ovules- Female sex cell, similar to the egg Stigma- Sticky part of the system, catches pollen Style-Tube that leads from the stigma to the ovary Ovary- Place where ovule is fertilized by the pollen, Turns into a fruit or seed coat

12. Primary Growth • Occurs in apical meristems of plant • (found at tips of stems and roots)

14. PROBLEM! IF THE CUTICLE BLOCKS WATER, WHAT ELSE IS PREVENTED FROM ENTERING/EXITING THE PLANT? C O 2 !!

15. Solution? • STOMATA! • Tiny pores in epidermis surrounded by two guard cells! • Open during the day! Why? • PS occurs during the day • Transpiration necessary for cooling

17. VASCULAR TISSUE • 2 MAJOR TYPES: • XYLEM TISSUE • PHLOEM TISSUE • Found together in VASCULAR BUNDLES • Arise primarily from apical meristem • Arise secondarily from vascular cambium

18. XYLEM TISSUE • CONDUCTS WATER • PROVIDES MECHANICAL SUPPORT • 2 TYPES OF XYLEM CELLS: • TRACHEIDS: • VESSEL ELEMENTS:

19. PHLOEM TISSUE • CONDUCTS SUGARS • COMPOSED OF TWO CELL TYPES: • SIEVE-TUBE MEMBERS • COMPANION CELLS

20. Sieve tube members • Form sieve tubes to conduct sugars throughout plant • Lack nuclei, ribosomes, vacuoles, etc. Vascular bundle

21. xylem

22. Stems • Transports food, water, and nutrients • Supports the leaves and flowers

23. Parts of the Stem • Xylem • Water and minerals travel up to other plant parts • Phloem • Manufactured food travels down to other plant parts • Cambium • Separates xylem and phloem

24. Types of Root Systems • Fibrous Roots • Easier to transplant • Short, small, compact roots • Tap Root • Difficult to transplant, since most of the tap root is cut-off • Tap root is primarily used for storage of food • In both types, most nutrients and water are absorbed by root hair

25. Fibrous Roots • Monocots • Several roots of same size w/ branching

26. Roots can be adapted for storage of nutrients: • Example: Carrot (Taproot) Sweet Potato (Fibrous Root)

28. Plant Processes • Photosynthesis • Mixes light, water, and carbon dioxide in the presence of chlorophyll to produce sugar and oxygen • Respiration • Combines sugars and oxygen to give off water and heat • Transpiration • Loss of water through the leaves or stems • Causes wilting when soil is dry

29. Animal Water Wind Dispersal of Seeds Force Gravity Wind

30. Let's have a short Review

31. Plant Systems • There are 3 main plant systems: • Reproductive – this is the flower structure • Transport – this is the stem and roots and their xylem and phloem • Energy – this is the leaf and other areas of photosynthesis.

32. Leaf Tissue – What happens where?