1. Topic 13
Plant Science

2. 13.1.1 Compare the 4 main types of plants by External Plant Structures
Bryophytes (mosses)
No roots, but rhizoids
Mosses = simple leaves & stem
Liverworts = flattened thallus
Max height = 0.5 meters
Reproduction = spores in a capsule at end of stalk

6. Filicinophytes (ferns)
True roots, leaves, short non-woody stem
Leaves are pinnate = in pairs of leaflets
Max height = 15 meters
Reproduction = spores in sporangia under leaves

8. Coniferophytes (conifers)
Shrubs or trees with roots, leaves, woody stems. Leaves are narrow with thick waxy cuticle
Maximum height = 100 meters
Reproduction = seeds in female cones. Male cones produce pollen

12. Angiospermophytes (flowering plants)
Usually have roots, leaves and stems. Stems may be woody or not.
Maximum height = 100 meters
Reproduction = seeds from flowers. Seeds in fruits.

16. Plan diagram of stem

17. Plan diagram of root

18. Plan diagram of leaf

19. Palisade mesophyll - main photosynthetic tissue
Explain the relationship between the distribution of tissues in the leaf and the functions of these tissues.
Palisade mesophyll - main photosynthetic tissue
Near surface where the light is most intense for photosynthesis
Upper epidermis
Upper surface protects internal structure of leaf from water loss.

20. Stoma - a pore/opening gas moves through
In lower surface - the barrier between leaf and atmosphere
Spongy mesophyll - main gas exchange surface
Near stomata in lower surface for easy gas exchange
Guard cells
A pair cells located on sides of stoma to open or close them

21. Xylem - Carry water from roots to other parts of plant
Phloem - Carry products of photosynthesis (glucose = food for plant)
Both are a vein that runs through center of leaf so all cells are near for exchange of materials

22. 13.1.5 Outline the adaptations of xerophytes
CAM and C4 physiology (Crassulacean acid metabolism)(phosphoenol pyruvic acid (C3) to form Oxoloacetic acid (C4)
Involves opening stomata during night, not day
Reduced leaves
Reduced surface area = reduced transpiration
Rolled leaves
Protected surface area = reduced transpiration
Thickened waxy cuticle
Keeps water in

23. reduced number of stomata stomata in pits surrounded by "hairs” Spines
Fewer openings for water to escape
stomata in pits surrounded by "hairs”
Holds water in
Spines
Reduces transpiration
deep roots
Absorb water deep down in soil
water storage tissue
Usable water during dry times

24. 13.1.6 Outline two structural adaptations of hydrophytes.
air spaces
Buoyancy = floating near surface
Flotation
Allows plant to be at surface = light
pliable parts with little strengthening tissue
Move with waves without breaking
"breathing" roots
Roots sent above surface of water

25. finely divided submerged leaves.
reduced roots
No need for roots = surrounded by water
finely divided submerged leaves.
Surface area for water absorption