1. The Structure of Flowering Plants

2. Contents External Structure The Root System Functions The Shoot System
Buds
Leaves
Flowers
Growth and Tissues in plants
Organisation of plant tissues
Types of tissues
Vascular Tissues in Angiosperms
Xylem
Phloem
Sieve tube cells
Companion cells
Monocot & Dicot plants

3. External Structure

4. The Root System

5. Roots Usually white in colour – why? Tip protected by root cap
Root hairs – absorb water and minerals

6. Functions of the root To anchor the plant in the ground
To absorb water and minerals from the soil
Sometimes to store food

7. The Shoot System Consists of an upright stem bearing Buds Leaves
Flowers

8. Functions of the stem
Transport water and minerals from the roots to all parts of the plant
Transport food from the leaves to all parts of the plant
Support the leaves and hold them up to the sun for light
Sometimes to store food

9. Buds (1/2) A bud is an undeveloped shoot
Apical buds – at tip of stem where growth takes place
Lateral buds – in axil of leaf – produce side shoots and branches

10. Buds (2/2) Axil = angle between the petiole of a leaf and the stem
Node = point on a stem where a leaf or leaves are attached
Internode = the part of a stem between two nodes

11. Leaves Lamina = flattened leaf blade Veination of leaf – two types
Netted e.g.
Parallel e.g.
Attachment to stem – two ways
Petiole e.g.
Sessile e.g.

12. Functions of the leaf To make food by photosynthesis
To allow exchange of gases – explain
To allow transpiration – explain
Sometimes to store food e.g.

13. Flowers Formed from flower buds
May occur singly or as an inflorescence
Four main parts
Sepals
Petals
Stamens
Carpels

14. Typical flower structure

15. Function of the Flower
Reproduction

16. Growth and Tissues in plants
meristem: tip of shoots and roots of plants. Area of active cell division (mitosis) which produces ‘simple’ cells which later undergo elongation and differentiation to give rise to the various plant tissues e.g. xylem, phloem, etc.
Apical meristems are found at tip of shoots and roots

17. Organisation of plant tissues

18. Types of tissues
When meristems divide they produce three types of tissue
Dermal – epidermis = outer covering
Ground – inside of plant
e.g. cortex and pith of stem
mesophyll of leaf
Vascular – transport tissue = xylem & phloem

19. Tissue types in L.S. of root

20. Tissue types in T.S. of root

21. Tissue types in L.S. of stem

22. Tissue types in T.S. of stem

23. Tissue types in T.S. (V.S.) of leaf

24. Vascular Tissues in Angiosperms
Two types
Xylem
provides support and
transports water and minerals
Phloem
transports food

25. Xylem Two kinds of conducting cell
xylem tracheids and
xylem vessels
On maturity both are dead, hollow and contain no cytoplasm

26. Xylem tissue

27. Xylem tracheids Long cells tapered at both ends
Pits in the walls – allow water and minerals to move sideways from cell to cell
Walls thickened with lignin for support

28. Xylem vessels Elongated cells with spiral bands of lignin
No end walls – form a continuous tube
Wider than tracheids

29. Phloem
Consists of
phloem sieve tube cells and
companion cells

30. T.S. of phloem tissue

31. L.S. of phloem tissue

32. Sieve tube cells Long cylindrical cells stacked end to end
End walls = sieve plates – have holes
Allow cytoplasm to move from cell to cell
Mature cells have no nucleus

33. Companion cells Found beside sieve tube cells
Has cytoplasmic connections with sieve tube cell
Has a nucleus which controls activities of both companion and sieve tube cell

34. Identification of Monocot & Dicot plants
Monocotyledons
Dicotyledons
Number of cotyledons
One
Two
Arrangement of vascular bundles in the stem
Scattered in the stem
In a distinct ring pattern
Leaf venation
Parallel
Netted
Number of flower parts
In threes
In fours and fives
Woody or herbaceous
Almost all are herbaceous, there are very few woody monocotyledons
May be woody or herbaceous

35. The differences between monocots and dicots

36. END