1. Plant Parts and Their Functions –
Structural Organization in Plants
2.
3. • The Root:
• absorption of water
• storing reserve food material
• synthesis of plant growth regulators
• Type of root system
• 1) tap root system (Dicot)
• 2) fibrous root system (monocot)
• 3) adventitious roots.
• grass, Monstera, banyan tree, roots arise from
parts of the plant other than the radicle .
4.
5. • root is covered at the apex by a thimble-like
structure called the root cap.
• Modified roots: carrot, turnip,sweet potato
• 4) prop roots: Hanging structures that support
a banyan tree.
• 5) stilt roots: stems of maize and sugarcane
have supporting roots coming out of the lower
nodes of the stem.
6. • Pneumatophores:
• Rhizophora growing in swampy areas, many
roots come out of the ground and grow
vertically upwards.
• They help to get oxygen for respiration.
7. The Stem
• The region of the stem where leaves are born
are called nodes.
• internodes are the portions between two
nodes.
• Modified stem-
• potato, ginger, turmeric, zaminkand,
colocasia
8. • Stem tendrils :
• Develop from axillary buds, are slender and
spirally coiled.
• help plants to climb such as in gourds,
cucumber, pumpkins, watermelon, grapevines.
• Thorns:
• Axillary buds of stems may also get modified into
woody, straight and pointed i.e thorns.
• Ex..Citrus, Bougainvillea.
• They protect plants from browsing animals.
9. • Some plants of arid regions modify their
stems into flattened (Opuntia), or fleshy
cylindrical (Euphorbia) structures.
• They contain chlorophyll and carry out
photosynthesis.
• Underground stems of some plants such as
grass and strawberry, etc., spread to new
niches
• when older parts die new plants are formed
10. The Leaf
• originate from shoot apical meristems.
• Leaf develops at the node
• bears a bud in its axil.
• The axillary bud later develops into a branch.
• Leaf has 3 parts..
• 1) leaf base
• 2) petiole
• 3) lamina
11.
12. • Leaf Venation
• 1) Reticulate (In Dicots generally)
• 2) Parallel (In monocots generally)
• Modifications of Leaves
• converted into tendrils for climbing as in peas.
• into spines [thorns] for defense as in cacti.
• fleshy leaves of onion and garlic store food.
• insectivorous plants such as pitcher plant,
(venus-fly trap)
13. Root Modification Stem Modification Leaf Modification
Carrot and Sweet
Potato.
Potato, Ginger,
Turmeric,
Zaminkand and
Colocasia
Onion and Garlic.
14. The Flower
• reproductive unit in the angiosperms.
• Bisexual androecium+ gynoecium in single
flower
• flower having either only stamens or only
carpels is unisexual.
• Aestivation: Arrangement of sepals or petals
in floral bud.
15. • Gynoecium: female reproductive part.
• It consist one or more carpel
• carpel consists of three parts …
• 1)Stigma
• 2)Style
• 3)ovary
• After fertilization,
• ovules - seeds
• ovary - fruit.
16. Androecium
• Androecium is composed of stamens.
• consists of a stalk / filament and anther.
• anther is usually bilobed
• each lobe has two chambers, the pollen-sacs.
• pollen grains are produced in pollen-sacs.
• sterile stamen is called staminode
17.
18. The Fruit
• It is a mature or ripened ovary develop after
fertilization.
• If a fruit is formed without fertilisation of the
ovary, it is called a parthenocarpic fruit.
• The ovules after fertilisation, develop into
seeds.
