Golden Key Points -Chapter6-Anatomy Of Flowering Plants

Golden Key Points 

Epidermal Tissue System (Plants):

• Consists of epidermal cells, stomata, and epidermal appendages (e.g., trichomes, hairs).
• Epidermis forms the outermost layer of the plant body, serving as a protective barrier.
• Stomata regulate gas exchange and transpiration.
• Trichomes and hairs aid in reducing water loss.

Ground Tissue System (Plants):

• Comprises parenchyma, collenchyma, and sclerenchyma cells.
• Parenchyma cells are versatile and involved in storage and photosynthesis.
• Collenchyma cells provide flexible support to growing parts.
• Sclerenchyma cells offer rigid support and protection to mature plant parts.

Vascular Tissue System (Plants):

• Includes xylem and phloem, responsible for water and nutrient transport.
• Vascular bundles can be open (with cambium) or closed (without cambium).
• Arrangement of xylem and phloem varies (radial or conjoint) depending on plant type.
• Dicotyledonous stems typically have cambium for secondary growth, while monocotyledonous stems do not.

Anatomy of Dicotyledonous Root:

• Consists of epidermis, cortex, endodermis, pericycle, vascular bundles, and pith.
• Casparian strips in endodermis regulate water movement.
• Pericycle initiates lateral roots and vascular cambium.
• Vascular bundles are arranged in a ring and are conjoint with endarch protoxylem.

Anatomy of Monocotyledonous Root:

• Similar to dicotyledonous root but lacks secondary growth.
• Typically has more than six xylem bundles.
• Pith is large and well-developed.
• No cambium present, thus no secondary tissues formed.

Anatomy of Dicotyledonous Stem:

• Consists of epidermis, cortex, endodermis, pericycle, vascular bundles, and pith.
• Hypodermis provides mechanical strength.
• Vascular bundles are arranged in a ring pattern.
• Pith is composed of parenchymatous cells with large intercellular spaces.

Anatomy of Monocotyledonous Stem:

• Has sclerenchymatous hypodermis and scattered vascular bundles.
• Vascular bundles are conjoint and closed.
• Pith is large and conspicuous.
• No differentiation of mesophyll into palisade and spongy parenchyma.

Dorsiventral (Dicotyledonous) Leaf Anatomy:

• Consists of epidermis, mesophyll, and vascular system.
• Epidermis covers both upper (adaxial) and lower (abaxial) leaf surfaces.
• Mesophyll differentiated into palisade and spongy parenchyma.
• Vascular bundles arranged in a reticulate venation pattern.

Isobilateral (Monocotyledonous) Leaf Anatomy:

• Similar to dorsiventral leaf but with some differences.
• Stomata present on both upper and lower leaf surfaces.
• Mesophyll not differentiated into palisade and spongy parenchyma.
• Vascular bundles generally of similar sizes, reflecting parallel venation.