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Key Questions:

1. How are the following adapted to their functions: a) root hair cells, b) xylem, c) phloem?
   • Root hair Cells have a large surface area to volume ratio to allow for effective transport of substances. The inside of the xylem vessels is made of dead Cells that are waterproof to allow water up the stem. The phloem are made of live Cells meaning transport can happen by active transport as well as diffusion.
2. How does increasing temperature, humidity and light intensity affect the rate of transpiration?
   • Increasing temperature increases transpiration due to increased evaporation of water from the stomata. Increasing humidity decreases the rate of transpiration due to the concentration of water Particles on the outside of the leaf being higher and therefore osmosis not occurring. Increasing light intensity increases the rate of transpiration due to the increase in the rate of photosynthesis.
3. Which parts of the plant are involved in transporting substances?
   • The roots, stem and leaves form a plant organ system for transport of substances around the plant.
4. What are translocation and transpiration and how do they work?
   • Transpiration is the process by which water evaporates from the leaves, through the opening of the stomata, which results in more water being drawn up from the roots. Translocation is the movement of nutrients and other substances from the leaves to the rest of the plant.This happens through diffusion and active transport.
5. What is the job of the root hair cells and how are they adapted to it?
   • Root hair Cells have a large surface area to volume ratio so that they are adapted for the efficient uptake of water by osmosis, and mineral ions by active transport.
6. What is the role of xylem tissue and how is it adapted for it?
   • Xylem tissue transports water and mineral ions from the roots to the stems and leaves. It is composed of hollow tubes strengthened by lignin adapted for the transport of water in the transpiration stream.
7. What is the role of the stomata and guard cells?
   • The role of stomata and guard Cells are to control gas exchange and water loss.
8. What is the role of the phloem and what is the name of this process?
   • Phloem tissue transports dissolved sugars from the leaves to the rest of the plant for immediate use or storage. The movement of food molecules through phloem tissue is called translocation.