Stem

• What is the structure of the epidermis in young, green plants?

  It is a single layer of closely packed cells covered with a waxy cuticle.
• Why is the waxy cuticle important for the epidermis?

  It reduces water loss from the plant.
• What may be present on the epidermis of young, green plants?

  Hairs may be present.
• How does the epidermis differ in woody stems compared to young, green plants?

  In woody stems, the epidermis is made up of multiple layers and is known as bark.
• What is the composition of the cortex in stems?

  The cortex is made up of thin-walled parenchyma cells.
• What role do turgid parenchyma cells in the cortex play?

  They provide support when they are turgid.
• What happens to a cell when it is turgid?

  The vacuole is full of water and pushes against the cell wall.
• What type of cells may be present in the cortex alongside parenchyma cells?

  A layer of collenchyma cells with thickened corners may be present.
• What is the arrangement of vascular bundles in stems?

  The vascular bundles are arranged in a ring.
• Where is the xylem located in the vascular bundle?

  The xylem is on the inner side of the vascular bundle.
• Where is the phloem located in the vascular bundle?

  The phloem is on the outer side of the vascular bundle.
• What separates the xylem from the phloem in the vascular bundle?

  The cambium separates the xylem from the phloem.
• What role does sclerenchyma tissue play in the vascular bundle?

  Sclerenchyma tissue surrounds the vascular tissue, providing support.
• What is the composition of the pith in stems?

  The pith is made up of parenchyma cells.
• What is stored in the pith cells?

  Starch is stored in the pith cells.
• What are the main functions of stems in plants?

  • Hold the aerial parts of the plant upright
  • Transport substances between the roots and leaves
  • Phloem carries food from leaves to the rest of the plant
  • Xylem carries water up the stem from the roots
• What is the function of phloem in plants?

  Phloem carries food from the leaves to the rest of the plant.
• What is the function of xylem in plants?

  Xylem carries water up the stem from the roots to the rest of the plant.
• What are the key terms related to stem anatomy?

  • Turgid: A cell is turgid when the vacuole is full of water and pushes against the cell wall.
  • Pith: The spongy tissue in the center of a stem, made up of parenchyma cells.