Plant Structure and Transport Tissues
Your plant's transport system has two main highways: xylem for water and phloem for food. Think of xylem as dead, hollow tubes strengthened with lignin spirals - like reinforced pipes that won't collapse under pressure.
The root's structure is organised in layers from outside to inside: epidermis, cortex, endodermis, pericycle, then the central transport tissues. The Casparian strip in the endodermis acts like a waterproof barrier, forcing water to take the symplastic route through living cells.
Phloem consists of living sieve tube elements (no nucleus, little cytoplasm) connected by companion cells packed with mitochondria. These companion cells do the hard work of actively loading sucrose into the transport system.
Quick Tip: Remember that glucose gets converted to sucrose for transport because sucrose won't be accidentally used up during the journey - it's purely for storage and transport!
Translocation moves sucrose from sources (like leaves) to sinks (like fruits) using pressure differences. High pressure at the source pushes sugars towards low pressure areas at the sink.
