1. Algae were faced with challenge of life with little light.

3. zygote
SPOROPHYTE (2n)
GAMETOPHYTE (n)
GREEN ALGA
BRYOPHYTE
FERN
GYMNOSPERM
ANGIOSPERM
Evolutionary trend of plants started in the sea and moved slowly to wet lands and then to dry lands.

4. Every plant around us today is a descendant of ancient species of green algae that lived in or near water and made it onto the land
700 million years

5. Darwin’s theory: Evolution by Natural Selection
Peppered moth experiment of H.B.D.Kettelwell :
more of light-colored moths survived in unpolluted area. In soot-blackened areas, more dark-colored moths survived.

8. Overview of Plant Body Shoot Root Stem: Support leaves
Leaves: Photosynthesis
Flowers: Reproduction
Root: * Anchors plant
* Absorbs H2O
* Stores food

9. Three Types of Plant Tissues:
1) Dermal Tissue - covers and protects
2) Vascular Tissue - distribute H2O and solutes
3) Ground Tissue - makes up bulk of plant body
Where do these tissues originate from?
Meristem Tissues
- Cells dividing constantly (mitosis)
- Two locations: * Apical
* Lateral

10. Shoot Apical Meristem divide to make new cells
Apical Meristem - located in tip of stem and root
- cells undergo mitosis and produce new cells
- increase plant length (primary growth)
Shoot Apical Meristem divide to make new cells
As the new cells move away from tip, they
elongate and form different tissues (maturation)
Root apical meristem divide to make new cells

11. Lateral Meristem - located in vascular cambium and rings of cork cambium
- make new vascular tissue and new epidermis (cork)
- increases plant girth
Vascular cambium
Cork cambium
thickening

12. Three Types of Ground Tissue:
- parenchyma - for storage
- sclerenchyma - for support
- collenchyma - for flexible support
parenchyma cells
Thin cell walls
Functions: photosynthesis, storage, secretion.
Large central vacuoles filled with product of photosynthesis
In plant roots that we eat: potatoes, radishes.
SCLERENCHYMA

13. Sclerenchyma Tissue
Though, thick cell wall. Lignin makes cell water proof and strengthen cell wall ( this is what made plants stand on land)
Strengthen and support other plant tissues
Two types: Fibers- next to vascular tissues. Ex. Cloth, rope, paper Sclerid- star-shaped. Ex. Pear gritty texture, peach pit.
PARENCHYMA
COLLENCHYMA
SCLERENCHYMA

14. Collenchyma Tissue SCLERENCHYMA
Uneven thickened cell wall with pectin ( this polysaccharide glues cellulose fibrils together & makes tissue pliable.
Provides flexible support to stems and leaves.
SCLERENCHYMA

15. Plant Ground Tissues SCLERENCHYMA Thin cell wall
Storage & photosynthesis
Uneven cell wall
Flexible support
Thick cell wall
Strength and support
SCLERENCHYMA
PARENCHYMA
COLLENCHYMA

16. Two Kinds of Plant Vascular Tissue
- Vessel Elements- pitted cell wall. Absence of end walls make water pipeline.
- Tracheids - pitted cell wall
Xylem
Phloem
- Carries H2O, dissolved nutrients.
- Upward movement.
- Dead at maturity.
- Sieve tube - perforated end walls
- transport sugar
- Companion Cells- assist loading of sugars to various regions of plants
- Carries products of photosynthsis.
- Up and downward movement.
- Alive at maturity
Companion cells
Sieve-tube
Vessels
Tracheids

17. Two Kinds of Dermal Tissue
Epidermis - Single layered.
Periderm - Multilayered cork
replaces epidermis.
- For protection.
- cuticle- a wax layer
reduces water loss.
- Epidermis/ from
apical meristem
- For protection and
reduction of water loss.
- Bark/ from cork cambium
periderm
cork cambium

18. Plants are classified into 2 groups based on their seed cotyledon
Cotyledon is the leaf-like structure in seeds that store and absorb food for plant embryo.
Monocotyledons (monocots) - one cotyledon
Dicotyledons (dicots) - two cotyledons

19. 2
4s/5s or
multiples
of these
netlike
form ring 1
3s or multiple of 3
parallel
scattered

21. Internal Structure of Stems
Monocot Dicot
Vascular
bundle
Epidermis
Cortex Pith
Vascular bundle
Epidermis
Ground tissue

22. Arrangement of Vascular Bundles (VB) in Monocots and Dicots
Dicot VB
vessels in xylem
vascular cambium
sieve tube
companion cells
Monocot VB
sclerenchyma
fibers
Vessels
in xylem
sieve tube
companion cells
air space
Sclerenchyma
fibers

23. Structure of Vascular Bundle in Stem
epidermis
collenchyma
sclerenchyma
parenchyma
xylem
pholem
epidermis
collenchyma
sclerenchyma
xylem
phloem
paranchyma

24. External Structure of Roots: Primary root - The first part to emerge from seed Lateral root - perpendicular to primary root
Tap Root Fibrous Root