1. Plant Structure and Function
Unit 9
Plant Structure and Function

2. Learning Objectives
Structure and functions of plant tissue, leaves, roots and stems.
Discuss – using examples – the four major plant divisions
Describe the three primary cell types that make up plant tissue
Describe the structure and function of the tissue types found in plants
Explain how roots and stems not only provide support, but also allow for the storage and transportation of nutrients throughout the plant
Make a drawing of the structures found in a typical leaf

3. Learning Objectives Describe the stages in a plant's life cycle.
Compare the sporophyte stage in a plants life cycle to the gametophyte stage

4. Origins of plant life Land plants evolved from green algae
Both multicellular eukaryotes
Both use photosynthesis to produce food
Both use chlorophyll
Both use starch as storage product
Both have cell walls made of cellulose

5. Plant Adaptation
Land plants have evolved adaptations that allow them to live on land
Retaining moisture
Cuticle – waxy layer
stomata
Transporting resources
Vascular system – collection of specialized tissues that bring water and nutrients up from roots and disperse sugars down from the leaves

6. Growing upright Reproducing on land
Lignin – provides structure and support, allows plant to grow upwards toward the sun
Reproducing on land
Pollen
Seeds – contains plant embryo

7. Plant Diversity

8. Bryophytes 24000 species Live in moist environments
Mosses, liverworts
Live in moist environments
Non-vascular land plants
Grow close to ground or on surfaces where they can absorb nutrients directly
Fertilization requires free water
Allow sperm to swim and fertilize eggs

9. Bryophytes
Liverworts – thin leathery body that grows flat on most soil or still water

10. Bryophytes Mosses Most common bryophytes
Do not have leaves, but have leaf like structures that are one cell thick arranged in spirals

11. Pteridophytes 300 million years old Club mosses, horsetails, ferns
Vascular plants that reproduce using spores
Fertilization requires free water
Cuticle and stomata present

12. Pteridophytes Club Mosses 11oo species Not true mosses
Wet, shady habitats
Oldest living group of vascular plants
Some look like tiny pine trees (Lycopodium)

13. Pteridophytes Horsetails 25 species Swamps, wetland areas
Tan, scale-like leaves that grow in whorls around tubular stem

14. Pteridophytes
Ferns
12000 species
Wet, humid habitats
Leaves – fronds

15. Seed Plants Vascular Cuticle and stomata present
Free water not needed for fertilization
Gymnosperm
Naked seeds (not enclosed in fruit)
Angiosperm
Flowering plants
Seeds enclosed in fruit

16. Gymnosperm Conifers 550 Species Mostly evergreen
Pollen and seed-baring cones
Pollen produced in male cones
Egg produced in female cones

17. Gymnosperm Cycads 130 species Look like palm trees with large cones
Tropical climates
Very slow growing - endangered

18. Gymnosperm Ginkgo One species Native to china
Closely resembles fossil ancestors

19. Angiosperms Flowering plants Dominate the plant kingdom
Flower – reproductive structure, protects plants gametes and fertilized eggs
Dominate the plant kingdom
Protect seeds with fruit
Peach
Wings attached to maple seed
Dandelion fluff

20. Angiosperms Monocots Parallel veins in long narrow leaves
Flower occurs in multiples of 3
Bundles of vascular tissue scattered throughout the stem

22. Angiosperms Dicots Leaves with net-like veins
Flowers occur in multiples of four or five
Vascular tissue arranged in rings
Embryo has two seed leaves (peanuts)