Phloem Transport

• Plants transport organic compounds from sources to sinks
• Active transport is used to load organic compounds into phloem sieve tubes at the source
• High concentrations of solutes in the phloem at the source lead to water uptake by osmosis
• Incompressibility of water allows transport along hydrostatic pressure gradients
• Raised hydrostatic pressure causes the contents of the phloem to flow towards sinks
• Structure and function are correlated in the phloem of plants
• What process does the phloem use to transport materials?

  active translocation
• What does the phloem transport?

  food and other organic substances
• Phloem occupy the outer portion of the vascular bundle and are composed of sieve tube elements and companion cells
• Phloem vessel walls consists of cells that are connected at their transverse ends to form porous sieve plates
• Vessels are composed of living tissue, however sieve tube elements lack nuclei and have few organelles
• A storage organ is a part of a plant specifically modified to store energy or water
• Examples of storage organs include bulbs, tubers, and storage roots
• Hyphae are the tubular projections of multicellular fungi that form a filamentous network (mycelium)
• Fungal hyphae release digestive enzymes in order to absorb nutrients from food sources
• What is it called when certain species of fungi form a symbiotic relationship with plants whereby both species benefit?

  mutualism
• What benefits do plants get from their relationship with fungi?

  Mineral transfer
• What benefits do fungi get from their relationship with plants?

  Nutrient absorption