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Practical General Biology . The Stem , The Root and The Leaf 2012_2013 . The Stem . Function of Stem : Stems support photosynthetic leaves and reproductive structures, thus increasing photosynthetic and reproductive efficiency. Stems supply water and minerals to shoots .
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Practical General Biology The Stem , The Root and The Leaf 2012_2013
The Stem Function of Stem : • Stems support photosynthetic leaves and reproductive structures, thus increasing photosynthetic and reproductive efficiency. • Stems supply water and minerals to shoots .
The Dicotolydonous Stem (Dicot stem) Component of dicot stem : • Epidermis, ground tissue (paranchyma, collenchyma, sclerenchuma, cortex, pith), vascular tissue (xylem, phloem ). • Protoxylem vessels : are the smallest vessels, their typical location is towards the pith. • Metaxylem vessels: are the larger vessels, their typical location is towards the cortex. • Fascicular cambium : is the area between the primary xylem and phloem . • Organization of bundle .
The Monocot Stem Component of monocot stem : • Epidermis, ground tissue (paranchyma, collenchyma, sclerenchuma), vascular tissue (xylem, phloem ). • Random arrangement of the vascular bundles, and its surrounding by sclerenchyma . • Not have secondary growth. • Xylem the same of V. • No have cortex and pith . • No have cambium layer .
The Monocot Root • A count of metaxylem if this above 8 it’s monocot root . • The roots of monocots are organized into a cortex, with primary xylem and primary phloem in central pith . • Not have secondary growth, because absent of cambium . • The area of pith are largest, and the phloem is combination with protoxylem . • Thicker from one side and have Casparian .
The Dicot Root • Number of vascular bundle from 4 to 5 only . • Have secondary growth and cambium it’s present . • Not have pith . • Phloem arrangement with xylem arm to formation vascular bundle . • Thicker form all side . • Have passage cell .
The Monocot Leaf • The vascular bundle it’s spread in the leaf . • Not differentiation of Mesophyll . • Distribution of Stomata it’s equal in the upper and lower of leaf . • Vascular bundles are enclosed by scalarenchyma . • Stomata are damples shape . • Have buliform cells . • Xylem are V shape . • venation in the leaf blade : Parallel venation .
The Dicot Leaf • Stomata are distribution in lower more than in upper. • Stomata are kidney shape . • Have not buliform cell in upper epidermis . • Mesophyll is homogenus and are distinguished between Palisade and Spongyparanchyma. • Vascular bundles are large and central and phloem is toward the lower epidermis .
The collenchyma present in upper and lower . • Waxy layer in upper epidermis are thicker . • Waxy layer in lower epidermis are thinner, because have stomata . • Have not scolarenchyma . • Venation in the leaf blade : Network venation .