1. (External & Internal Structures)
plants
(External & Internal Structures)
(Part 1)

2. Shoot system Root system leaf blade axillary bud petiole node
vascular tissue
shoot apical meristem
terminal bud
internode
Shoot
system
vascular tissue
Root
system
root tip
root hair
root cap
root apical meristem
dermal tissue
ground tissue
vascular tissue

3. ROOTS

4. Types of root systems
Tap root system
Fibrous root system

5. Primary Root System
Primary Root
Secondary Root
Tertiary Root

6. Fibrous Root System
The primary root is lost and is replaced by numerous adventitious roots arising from the lower part of the stem. These roots are fibrous in appearance , that is, they are slender in form and are more or less equally prominent

7. The Root Tip Elongation region Meristematic region Root cap
Cells in this region increase in size, particularly in length
The Root Tip
Meristematic region
Actively dividing cells in various stages of mitosis
Root cap
Produces mucigel for protection, lubrication, water and nutrient absorption

8. Three primary meristems
Protoderm
outermost primary meristem – gives rise to epidermis.
Ground Meristem
store food and uptake of minerals
Procambium
gives rise to stele – central cylinder of vascular tissue where xylem and phloem develop
Quiescent Zone
slower or no cell division

9. Maturation region characterized by the presence of root hairs
is made up of primary tissues that develop from transitional meristems of the elongation region
Protoderm
epidermis
Ground meristem
cortex
pericycle
phloem
Procambium
vascular cambium
xylem

10. Root hairs
Increase the surface area
for the absorption of water

11. Young dicot root epidermis cortex vascular cylinder Exarch - tetrarch
Stele - actinostele

12. cortex
endosperm with casparian strip
pericycle
xylem
phloem
vascular cambium

13. lateral root arising from
pericycle
xylem
phloem
endodermis with
casparian strip
cortical parenchyma
uncutinized epidermis with
root hair

14. Lateral roots develop from the pericycle
primary root
xylem
lateral root
Lateral roots develop from the pericycle

15. Monocot root epidermis cortex endodermis pericycle pith xylem phloem
root hairs

16. Exarch
polyarch
Stele
actinostele

17. Modified Roots

18. For Support - Brace roots
Aerial roots arising from the main stem which penetrates the ground
Corn (Zea mays)
Pandan (Pandanus odoratissimus)

19. For Support - Prop roots
Aerial roots arising from the branches which penetrates the ground
Banyan tree (Ficus indica)
Mangrove (Rhizophora sp.)

20. For Support – Clinging roots
Aerial roots which adhere to some kind of support
English ivy (Hedera helix)

21. For Support - Buttress
Plant-like extensions from the lower part of the stem
Ficus sp.

22. Adventitious buds in root
For Reproduction
Adventitious buds in root
Bog Yellowcress (Rorippa palustris)

23. For Protection
Screw pine (Pandanus tectorius)
Presence of spines

24. For Photosynthesis
Green aerial roots
Vanda sp.

25. For Food Storage enlarged, fleshy and succulent roots
White Radish (Raphanus sativus)
Carrot (Daucus carota)

26. For Aeration
development of pneumatophores – roots with spongy tissues protruding above the ground
Mangrove (Rhizophora sp.)