Concepts to remember on the “Structural Organization Anatomy of Flowering Plants” for JEE and CBSE board exams:

Plant Tissue Systems:

• Meristematic Tissues: Undifferentiated cells that divide continuously to produce new cells.

• Permanent Tissues: Are differentiated cells that perform specialized functions and have lost the ability to divide. Further classified into Simple and Complex tissues.

• Simple Permanent Tissues: Parenchyma, Collenchyma, Sclerenchyma

• Complex Permanent Tissues: Xylem and Phloem

Plant Organs:

• Root: The part of the plant that grows underground and anchors the plant in the soil, absorbs water and nutrients, and stores food.
• Stem: The part of the plant that grows above the ground and supports the leaves, flowers, and fruits. It also transports water and nutrients from the roots to the rest of the plant.
• Leaf: The primary photosynthetic organ of the plant that absorbs sunlight and converts it into energy through photosynthesis.
• Flower: The reproductive structure of the plant that produces seeds.
• Fruit: The ripened ovary of a flower that contains seeds.
• Seed: The reproductive unit of a flowering plant that contains an embryo, food storage tissue, and a protective coat.

Root Anatomy:

• Types of Roots:
• Taproot: A single, dominant root that grows straight down into the ground.
• Adventitious Roots: Roots that arise from stems or leaves.
• Root Apex and its Structure:
• Root Cap: A protective layer of cells at the tip of the root that helps it penetrate the soil.
• Meristematic Zone: Where new cells are produced.
• Primary Growth of Root: The elongation of the root due to cell division in the meristematic zone.
• Secondary Growth of Root: The increase in the thickness of the root due to the activity of the vascular cambium.

Stem Anatomy:

• Types of Stems:
• Herbaceous Stems: Soft, green, and non-woody stems.
• Woody Stems: Hard, brown, and woody stems.
• Node and Internode:
• Node: The region where leaves are attached to the stem.
• Internode: The region between two nodes.
• Primary Growth of Stem: The increase in the length of the stem due to cell division in the meristematic zone.
• Secondary Growth of Stem: The increase in the thickness of the stem due to the activity of the vascular cambium.

Leaf Anatomy:

• External Morphology of a Leaf:
• Leaf Blade: The flat, expanded part of the leaf.
• Petiole: The stalk that connects the leaf blade to the stem.
• Stipules: Small leaf-like structures at the base of the petiole.
• Internal Structure of a Leaf:
• Mesophyll: The middle layer of the leaf that contains chloroplasts.
• Veins: Strands of vascular tissue that transport water and nutrients throughout the leaf.
• Epidermis: The outermost layer of the leaf that protects the leaf from water loss and mechanical damage.
• Types of Leaves:
• Simple Leaves: Leaves with a single blade.
• Compound Leaves: Leaves with multiple leaflets.
• Venation: The arrangement of veins in a leaf.

Flower Anatomy:

• Parts of a Flower:
• Sepals: Leaf-like structures that form the outermost layer of the flower.
• Petals: Colorful leaf-like structures that attract pollinators.
• Stamens: The male reproductive organs that produce pollen.
• Pistil: The female reproductive organ that produces ovules.
• Stamen:
• Anther: The part of the stamen that produces pollen.
• Filament: The stalk of the stamen that supports the anther.
• Pistil:
• Stigma: The part of the pistil that receives pollen.
• Style: The stalk of the pistil that connects the stigma to the ovary.
• Ovary: The swollen base of the pistil that contains the ovules.
• Ovule: The reproductive unit of the flower that develops into a seed after fertilization.

Fruit Anatomy:

• Structure of a Fruit:
• Pericarp: The outer wall of the fruit that protects the seeds.
• Mesocarp: The fleshy middle layer of the fruit.
• Endocarp: The inner layer of the fruit that surrounds the seeds.
• Types of Fruits:
• Simple Fruits: Fruits that develop from a single ovary.
• Aggregate Fruits: Fruits that develop from multiple ovaries in the same flower.
• Multiple Fruits: Fruits that develop from multiple flowers in the same inflorescence.

Seed Anatomy:

• Structure of a Seed:
• Seed Coat: The protective outer layer of the seed.
• Embryo: The young plant that develops from the zygote.
• Endosperm: The food storage tissue of the seed.