LECTURE 5 botany plants tissue animal food and digestive

Plants

1. ROOTS
LECTURE 5

3. FUNCTIONS OF ROOTS
PLANT STABILITY:
Roots anchor plants to a substrate for
stability.

4. FUNCTIONS OF ROOTS
PLANT STABILITY:
Roots anchor plants to a substrate for
stability.
Essential for upright growth in trees, shrubs,
and epiphytes.

5. FUNCTIONS OF ROOTS
PLANT STABILITY:
Roots anchor plants to a substrate for
stability.
Essential for upright growth in trees, shrubs,
and epiphytes.
Provides stability for aerial structures in
rhizomatous plants.

6. Rhizomatous Plants
Rhizomes - specialized underground
stems that grow horizontally
beneath the soil

7. FUNCTIONS OF ROOTS
Absorbing Water and Minerals:
Roots absorb water and minerals from
the soil/substrate
Cylindrical shape
Root hairs

8. FUNCTIONS OF ROOTS
Producing Hormones:
Roots produce hormones like cytokinin and
gibberellin.
These hormones are crucial for shoot growth
and development.

9. CYTOKININ GIBBERELLIN
Cell division Promotion of Stem Elongation
Leaf Growth and Differentiation Seed Germination
Regulation of Growth Flowering and Fruit Development

10. ORIGIN OF THE ROOT
Radicle

12. Grows straight down from
the seed and becomes the
central root
Large and robust
Can store nutrients and
water
Examples:

14. Primary root dies off early , and a
network of adventitious roots
emerges
Consists of many roots of similar
size that form a mat-like structure.
Examples:

15. Roots arise from plant parts except
the radicle
Can arise from any nodes,
internodes, stem, or branch or even
from the leaf
Benefits: Adaptability and Survival

16. SPECIALIZED ROOTS
Storage Roots
Fleshy taproots
These store carbohydrates during
periods of dormancy and stress.
Ex. Sweet potatoes, Carrots, Turnips etc

17. Are "root crops" true storage roots?

18. Type: Bulb (a modified stem)
Function: The bulb stores nutrients in
the fleshy leaves, which help the plant
survive during dormant periods and
regrow in the next growing season.
Key Point: Onions are not roots but
modified stems with storage leaves.
Onion

19. Potatoes
Type: Tuber (a modified stem)
Function: stores energy and
nutrients, and each "eye" can
grow into a new plant,
Key Point: Potatoes are modified
stems, not roots, even though
they grow underground and store
nutrients

20. Ginger
Type: Rhizome (a modified
stem)
Function: stores energy and
nutrients
A type of Rhizomatous plant

21. GENERAL STRUCTURE OF A ROOT

22. Root Tip and Cap:
Growth in length occurs at the root tip.
Root cap protects the apical meristem and
secretes mucigel for lubrication.
STRUCTURE OF
INDIVIDUAL ROOTS

23. Root Tip and Cap:
Growth in length occurs at the root tip.
Root cap protects the apical meristem and
secretes mucigel for lubrication.
Zone of Elongation:
Cells divide and expand, starting to differentiate.
STRUCTURE OF
INDIVIDUAL ROOTS

24. Root Tip and Cap:
Growth in length occurs at the root tip.
Root cap protects the apical meristem and
secretes mucigel for lubrication.
Zone of Elongation:
Cells divide and expand, starting to differentiate.
Zone of Maturation:
Presence of root hairs for increased absorption
Resources and support
Complete development
STRUCTURE OF
INDIVIDUAL ROOTS

25. INTERNAL STRUCTURE
OF ROOTS
Root Apical Meristem:
Quiescent center acts as a reserve of
healthy cells.

27. MICROSCOPIC IMAGE OF A ROOT: MONOCOT

28. MICROSCOPIC IMAGE OF A ROOT: MONOCOT

29. MICROSCOPIC IMAGE OF A ROOT: DICOT/EUDICOT

30. MICROSCOPIC IMAGE OF A ROOT: DICOT/EUDICOT

31. MICROSCOPIC IMAGE OF A ROOT: DICOT/EUDICOT

32. MICROSCOPIC IMAGE OF A ROOT: DICOT/EUDICOT

33. Origin and Development of Lateral Roots
Initiated by cell divisions in the pericycle.
New lateral roots emerge and connect to the vascular tissues
of the parent root.

34. OTHER TYPES OF ROOTS AND MODIFICATIONS
Prop Roots:
Extensive growth through the air,
providing stability.

35. Balete Tree Mangrove Tree

36. OTHER TYPES OF ROOTS AND MODIFICATIONS
Aerial Roots of Orchids:
Adapted to drought
conditions with a
waterproof barrier.

37. Symbiotic roots
Mycorrhizae:
Symbiotic relationship with soil fungi.
Ectomycorrhizal and endomycorrhizal
relationships.
Root Nodules and Nitrogen Fixation:
Chemical conversion of atmospheric
nitrogen.

38. Parasitic Roots
Haustorial Roots of Parasitic Plants:
Modified roots for adhering to and
penetrating the host.
Roots of Strangler Figs:
Cling to and eventually replace the host
tree.

39. Thank you!