Plant tissues, organs and systems

• What does the waxy cuticle of epidermal tissue help reduce?

  Water loss
• Palisade mesophyll tissue contains lots of chloroplasts
• Spongy mesophyll tissue has air spaces for gas diffusion.
• What material strengthens xylem vessels and makes them waterproof?

  Lignin
• Phloem cells are elongated and living
• What type of cells make up meristem tissue?

  Stem cells
• The leaf organ contains xylem, phloem, and guard cells.
• Guard cells control the opening and closing of stomata
• What do root hair cells absorb from the soil?

  Water and minerals
• Root hair cells have a large surface area to maximize absorption.
• Transpiration is the evaporation of water vapour from the surface of a plant
• Steps in the process of transpiration

  1️⃣ Water evaporates from the leaf surface

  2️⃣ Water molecules cohere and are pulled up

  3️⃣ More water is taken up from the soil
• Increasing temperature increases the rate of transpiration.
• Increasing relative humidity decreases the rate of transpiration
• What happens to the water vapour concentration outside the leaf when wind speed increases?

  It decreases
• Higher light intensity increases the rate of transpiration.