4.2.3 plant tissues, organs and organ systems

• What is cancer described as in GCSE Biology?


  Cancer is the result of changes in cells that lead to uncontrolled growth and division.
• What are benign tumors?


  Benign tumors are growths of abnormal cells contained in one area, usually within a membrane.
• How do malignant tumor cells differ from benign tumors?


  Malignant tumor cells invade neighboring tissues and spread to different parts of the body.
• What are the two types of risk factors identified for cancer?


  Lifestyle risk factors and genetic risk factors.
• What should students be able to explain about plant tissues?


  Students should be able to explain how the structures of plant tissues are related to their functions.
• What are the main types of plant tissues?

  • Epidermal tissues
  • Palisade mesophyll
  • Spongy mesophyll
  • Xylem and phloem
  • Meristem tissue (found at the growing tips of shoots and roots)
• What is the leaf classified as in plant biology?


  The leaf is classified as a plant organ.
• What should students be able to explain about root hair cells, xylem, and phloem?


  Students should be able to explain how the structure of root hair cells, xylem, and phloem are adapted to their functions.
• What factors affect the rate of transpiration in plants?

  Changing temperature, humidity, air movement, and light intensity affect the rate of transpiration.
• How can students measure the rate of transpiration?

  By measuring the uptake of water.
• What is the role of stomata and guard cells in plants?

  The role of stomata and guard cells is to control gas exchange and water loss.
• What is the function of xylem tissue in plants?

  Xylem tissue transports water and mineral ions from the roots to the stems and leaves.
• What is the composition of xylem tissue?


  Xylem tissue is composed of hollow tubes strengthened by lignin.
• What is translocation in plants?

  Translocation is the movement of dissolved sugars from the leaves to the rest of the plant for immediate use or storage.
• What is phloem composed of?

  Phloem is composed of tubes of elongated cells.
• How does cell sap move through phloem tissue?

  Cell sap can move from one phloem cell to the next through pores in the end walls.
• What are the processes of transpiration and translocation in plants?

  • Transpiration: The process of water movement through a plant and its evaporation from aerial parts.
  • Translocation: The movement of dissolved sugars from the leaves to the rest of the plant.
• Is detailed structure of phloem tissue or the mechanism of transport required for GCSE Biology?

  No, detailed structure of phloem tissue or the mechanism of transport is not required.