Plant transport systems + Transpiration

• What is the process of transporting sugars in plants called?

  Translocation
• How do plants transport water?

  Through transpiration
• Where does photosynthesis occur in plants?

  In the leaves
• What are phloem cells primarily responsible for?

  Transporting sugars
• What do we call the long columns formed by phloem cells?

  Phloem tubes
• What is cell sap?

  A liquid mixture of water and sugar
• What can sugars be used for once transported to cells?

  For energy or storage
• In which directions can phloem transport substances?

  Up or down the plant
• What are xylem tubes made of?

  Dead xylem cells
• What strengthens xylem tubes?

  Lignin
• What is the role of xylem tubes?

  Transporting water and mineral ions
• What drives the movement of water through a plant?

  Evaporation of water from leaves
• What is transpiration?

  Evaporation of water from leaves
• What is the transpiration stream?

  The chain of water molecules moving up
• What factors influence the rate of transpiration?

  Light intensity, temperature, airflow, humidity
• How does light intensity affect transpiration?

  Higher light increases photosynthesis and transpiration
• How does temperature affect the rate of transpiration?

  Warmer temperatures increase evaporation rates
• How does airflow affect transpiration?

  High airflow increases the concentration gradient
• How does humidity affect transpiration?

  Higher humidity decreases the concentration gradient
• Why does transpiration occur at a higher rate during the day?

  More stomata are open for photosynthesis
• What happens to transpiration at night?

  Transpiration decreases due to closed stomata
• What is the relationship between concentration gradient and transpiration?

  A stronger gradient increases the rate of transpiration
• What happens to water molecules when they evaporate from leaves?

  They create a pull that drags other molecules up
• What is the main purpose of transpiration in plants?

  To transport water and minerals
• What are the two main types of transport in plants?

  Movement of water and minerals, glucose and amino acids
• What are the transport systems in plants for moving food, water, and minerals?

  • Xylem: moves water and solutes from roots to leaves
  • Phloem: moves glucose and amino acids throughout the plant
• What does the xylem transport?

  Water and solutes from roots to leaves
• What does the phloem transport?

  Glucose and amino acids to the rest of the plant
• How do the xylem and phloem differ in their structure?

  Xylem has dead cells; phloem has living cells
• How are xylem and phloem arranged in plants?

  • Found in vascular bundles
  • Arrangement differs in stems and roots
• What material makes xylem vessels tough?

  Lignin, a woody material
• Why are vascular bundles in the roots located in the center?

  To prevent the plant from being pulled out
• Why are vascular bundles in the stem located nearer to the edge?

  To provide strength and support to the stem
• How does the movement of substances differ between xylem and phloem?

  Xylem moves substances one way; phloem moves both ways
• What substances do xylem and phloem transport, and in which direction?

  • Xylem: water and minerals upwards
  • Phloem: sucrose and amino acids up and down
• Plants have two separate types of transport vessel - xylem and phloem - for transporting substances around
• Phloem tubes transport food substances ( mainly dissolved sugars )
• Phloem tubes are made of columns of living cells called sieve tube elements. These have perforated end-plates to allow stuff to flow through
• Sieve tube elements have no nucleus; they can't survive on their own so each sieve tube element has a companion cell
• Companion cells carry out the living functions for both themselves and their sieve cells