leaf structure

• What should you be able to describe by the end of the video on plant tissues?

  The roles of the different tissues in a plant
• Why is it important to learn the details presented in the video?

  Because it is very likely to be on your exam
• Where does photosynthesis take place in a plant?

  In the leaves
• What is the leaf classified as in terms of plant organs?

  A plant organ that contains different tissues
• What are the thin cells covering the top and bottom of the leaf called?

  Epidermal cells
• What is the function of the epidermis in a leaf?

  To protect the surface of the leaf
• What is a key adaptation of the upper epidermis?

  It is transparent, allowing light to pass through
• What does the waxy cuticle do for the leaf?

  It reduces the evaporation of water from the surface of the leaf
• What are the tiny pores on the lower epidermis called?

  Stomata
• What is the function of stomata in a leaf?

  To allow carbon dioxide to enter and oxygen to leave
• What do guard cells do in relation to stomata?

  They help control the amount of water vapor that can pass out of the leaf
• What is found at the top of the leaf?

  The palisade mesophyll
• What are palisade cells packed with?

  Chloroplasts
• What is the role of chloroplasts in palisade cells?

  To absorb the light energy needed for photosynthesis
• What is a key feature of the spongy mesophyll?

  It is full of air spaces
• How do air spaces in the spongy mesophyll assist in gas exchange?

  They allow carbon dioxide to diffuse to the palisade cells and oxygen to diffuse to the stomata
• What are the two other tissues in the leaf besides mesophyll?

  Xylem and phloem
• What is the function of xylem tissue?

  To transport water from the roots to the stem and leaves
• What mineral is transported by xylem and is essential for making chlorophyll?

  Magnesium
• What does phloem tissue transport?

  Dissolved sugars produced by photosynthesis from the leaves to the rest of the plant
• What is the immediate use of glucose transported by phloem?

  It is used in respiration
• What is the process of moving sugars through phloem tissue called?

  Translocation
• What is meristem tissue responsible for?

  It contains stem cells that can differentiate into different types of plant tissue
• Where can meristem tissue be found in a plant?

  At growing tips, such as shoots and roots
• What are the main roles of different tissues in a plant?

  • Epidermal tissue: Protects the leaf surface
  • Palisade mesophyll: Contains chloroplasts for photosynthesis
  • Spongy mesophyll: Allows gas exchange through air spaces
  • Xylem: Transports water and minerals
  • Phloem: Transports sugars
  • Meristem: Contains stem cells for growth and differentiation
• What should you expect to find in the provided workbook on plant tissues?

  Plenty of questions on plant tissues
• What are the different levels of organization in plants?

  Cells combine to form tissues, tissues combine to form organs, and organs combine to form organ systems.
• What is the function of the organ system formed by leaves, stems, and roots in plants?

  The function is the transport of substances around the plant.
• What is the primary function of leaves in plants?

  • Leaves are the site of photosynthesis.
  • They require carbon dioxide and water to make sugars.
  • Water is transported from the soil by roots and xylem.
  • Carbon dioxide diffuses into the leaf through stomata.
• What are stomata?


  Stomata are small holes on the leaf surface that allow carbon dioxide to diffuse into the leaf.
• Where are stomata primarily located on a leaf?

  Stomata are primarily scattered through the lower epidermis of the leaf.
• What is the role of spongy mesophyll tissue in a leaf?

  Spongy mesophyll tissue allows gas to easily diffuse through due to its air gaps between the cells.
• Where does most of the photosynthesis occur in a leaf?

  Most of the photosynthesis occurs in the palisade mesophyll layer.
• What are chloroplasts?


  Chloroplasts are organelles packed in palisade cells that carry out photosynthesis.
• How are sugars transported in a plant after photosynthesis?


  Sugars are carried to the rest of the plant by the phloem.
• What are the adaptations of leaves to minimize water loss?

  • Leaves have a waxy cuticle on top to prevent water loss.
  • Stomata are kept open for short times to maximize carbon dioxide absorption while minimizing water loss.
  • Guard cells control the opening and closing of stomata based on water availability.
• What happens to guard cells when a plant has lots of water?

  Guard cells become turgid, making the gap between them larger to allow more carbon dioxide to diffuse through.
• What occurs to guard cells when a plant is short of water?

  Guard cells lose water due to osmosis and become flaccid, closing the stomata to conserve water vapor.
• Why do guard cells close at night?

  Guard cells close at night because photosynthesis isn't taking place and carbon dioxide is not needed.
• Why are most stomata located on the underside of leaves?

  Most stomata are on the underside of leaves because it is more shaded and cooler, reducing water evaporation.