1. Plants CH 22 and 23
Honors Biology

2. Vocab Prep 22.1-22.2 (in textbook) Divide and conquer
Alternation of Generations
Sporophyte
Gametophyte
Greek Root Words:
Phyta/Phyte
Bryophyte
Vascular Tissue
Archegonium
Antheridium
Sporangium
Tracheophyte
Tracheid
Xylem
Phloem
Seed
Gymnosperm
Angiosperm
Pollination
Ovule

3. Characteristics of Plants
Kingdom Plantae
Eukaryotes
Contain cell walls (cellulose)
Chlorophyll a and b
Why do they need these?
Autotrophs

4. Killer Plants? Parasites
Use a haustorium (modified stem or root) to “steal” nutrients and water from host plant.
Ex: Mistletoe!
Venus Fly Trap??
Basically creates it’s own fertilizer

5. What do plants need? Sunlight Gas Exchange Water and Minerals Resource
How do they get it?
Sunlight
Gas Exchange
Water and Minerals

6. Plant Evolution Where did life begin?
First plants in fossil record are similar to green algae
How did plants evolve for life on land?
First land plants were small and found only in damp areas
Greatest challenge = how to get water
Had to be resistant to drying out
Needed to be able to reproduce without water

7. Alternation of Generations

10. Seedless Nonvascular Plants
Green Algae
Mostly aquatic
Do not contain specialized tissues
Uses both sexual and asexual reproduction
Lack true vascular tissue

11. What is the benefit of having both?
Zygote resistant to harsh conditions

12. Bryophytes (mosses)
Can live on land
Seedless
Lack true vascular tissue so they are small
Alternation of generations (gametophyte dominant)
Needs water to reproduce

14. Vascular Plants (Tracheophytes)
Xylem: tissue that carries water from roots to shoots
Contain tracheids made of lignin and vessel elements
Both made of dead cells
Phloem: tissue that transports sugars from shoots to roots
Sieve tube elements and companion cells
Made of live cells
Allows plants to be taller
Alternation of Generations (Sporophyte dominant)

15. Seedless Vascular Plants
Club moss, horse tail and ferns

16. Requires water for fertilization

17. Seed Plants
Seed= plant embryo and food supply encased in protective covering
Evolutionary significance?
Type of Seed Plants
Gymnosperms
Cone contain seeds (naked)
Angiosperms
Flowers contain seeds (protected by ovary)
We will discuss this when we get to Genetics

21. Plant Tissues 1. Dermal Tissue Protection
Often covered by waxy cuticle
May have Trichomes (fuzzy)

22. 2. Vascular Tissue
Support and transport
Xylem and Phloem

23. Produces and stores sugars Contribute to physical support Contains:
3. Ground tissue
Produces and stores sugars
Contribute to physical support
Contains:
Parenchyma Cells: thin cell walls, found in leaves and contain chloroplasts
Collenchyma Cells: thicker cell walls, celery
Sclerenchyma: thickest cell walls, seed coats

24. 4. Meristems
Produces new cells
Apical meristems: responsible for growth in length or roots and stems
Floral meristems: responsible for growth of flowers

25. Organs of Seed Plants 1. Roots Function:
Anchor and prevent soil erosion
Work with bacteria a fungi to absorb water and nutrients
Types
1. Taproots
2. Fibrous Root

26. 2. Stems
Function:
Produce leaves, branches and flowers
Support
Transport
Growth of Stems
Primary: apical meristems add length through cell elongation

27. Secondary: increase in thickness
Rare in monocots
Vascular cambium gives rise to new layers of xylem and phloem so that stem becomes wider
This secondary xylem is wood
Bark: tissues found outside vascular cambium
-includes: Pholem, cork
cambium which
produces cork
(waterproofs)

28. Xylem near the center no longer conducts water and is called heartwood (dark color)
Sapwood does conduct water (light color)
How do you age a tree?
Count the rings
(analyzing
data p. 678)

29. 3. Leaves
Consists of ground tissue called mesophyll
Palisade mesophyll: absorbs light
Spongy mesophyll: contains air spaces for gas exchange via the stomata
Guard cells control the opening and closing

30. Transpiration