Demonstration of Stomata on a Leaf Peel - MeitY OLabs

00:03:38
https://www.youtube.com/watch?v=UG08SsO8zQA

摘要

TLDRThe video demonstrates the process of observing stomata on a leaf peel. Stomata are tiny pores on the epidermal layer of plant parts above the ground, including leaves, which facilitate gas exchange. The procedure involves carefully peeling the epidermis from the lower surface of a balsam leaf, staining it with Safranin, and observing under a compound microscope. The main components of stomata, the guard cells, are highlighted. It’s noted that stomata are more prevalent on the lower surface of leaves. The precautions involve using fresh leaves and clean equipment to ensure clear observation of the stomata.

心得

  • 🔎 Stomata allow gas exchange in plants.
  • 🌿 Stomata are found more on the lower leaf surface.
  • 🧪 Safranin stains the epidermis for visibility.
  • 🖋 Guard cells surround each stoma.
  • 🔬 Use a compound microscope for observation.
  • 💧 Glycerine preserves the peel on the slide.
  • 📄 Excess stain should be washed off.
  • 🧼 Clean glass slides are crucial for clarity.
  • 🔧 Special tools like needles and forceps are required.
  • 🧑‍🔬 Handle the epidermis gently to avoid damage.

时间轴

  • 00:00:00 - 00:03:38

    Stomata are tiny pores on the epidermal layer of plants, crucial for gas exchange, and this experiment will demonstrate how to view them. Required materials include a Balsam leaf, microscope, and various reagents. The procedure involves extracting the lower epidermis of a Balsam leaf, staining it with Safranin, and examining it under a microscope. The epidermis consists of cells with distinguishable features and stomata, seen as openings guarded by specialized cells. Ensure the epidermal peel is fresh and from the leaf's lower surface for better visibility of stomata.

思维导图

视频问答

  • What is the main function of stomata?

    Stomata allow gases such as carbon dioxide, water vapor, and oxygen to move rapidly in and out of the leaf.

  • How do you prepare a leaf sample for observing stomata?

    The leaf is peeled, stained with Safranin, and mounted on a glass slide with glycerin for microscopic examination.

  • Where are stomata more concentrated on a leaf?

    Stomata are generally more concentrated on the lower surface of a leaf.

  • Why is Safranin used in this experiment?

    Safranin is used to stain the epidermal peel, making the stomata more visible under the microscope.

  • What are guard cells?

    Guard cells are specialized cells that surround the tiny pores called stomata, helping to regulate their opening and closing.

  • Why should the epidermal peel be taken from a freshly plucked leaf?

    A freshly plucked leaf ensures that the cells and stomata are intact and easier to observe.

  • What equipment is needed for the experiment?

    Equipment includes a needle, brush, glycerine, cover slip, compound microscope, and more.

  • How long should the peel remain in Safranin solution?

    The peel should remain in Safranin solution for about 30 seconds to stain properly.

  • What should you do if there’s excess glycerine on the slide?

    Excess glycerine should be drained using blotting paper.

  • Why is the epidermal layer important for observing stomata?

    The epidermal layer contains the stomata which are crucial for gas exchange in plants.

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  • 00:00:11
    Demonstration of stomata on a leaf peel
  • 00:00:14
    Introduction
  • 00:00:17
    In a plant, the epidermal layer is the outermost layer which contains tiny pores known as stomata.
  • 00:00:23
    The epidermal layer is found on all above-ground parts of plants, including the petals of flowers,
  • 00:00:28
    petioles, soft herbaceous stems and leaves.
  • 00:00:29
    Stomata permit the exchange of gases between the atmosphere and the inside of the leaf.
  • 00:00:33
    They consist of two specialized cells, called guard cells that surround a tiny pore called
  • 00:00:38
    stoma.
  • 00:00:40
    Their main function is to allow gases such as carbon dioxide, water vapor and oxygen
  • 00:00:45
    to move rapidly in and out of the leaf.
  • 00:00:49
    In different plants, distribution, number, size and type of stomata vary.
  • 00:00:54
    In general, the stomata are fewer in number on the upper surface as compared to the lower
  • 00:01:01
    surface of the leaf.
  • 00:01:07
    To do the experiment, we require: Needle, brush, Glycerine, cover slip, a fresh
  • 00:01:15
    leaf of Balsam, glass slide, watch glasses, distilled water, Safranin solution, forceps,
  • 00:01:25
    filter paper, compound microscope and dropper.
  • 00:01:31
    Procedure:
  • 00:01:33
    Pluck a fresh leaf from a balsam plant.
  • 00:01:38
    Fold the leaf and carefully tear along the bruised area on the lower side of the leaf.
  • 00:01:43
    We can see a colourless narrow border along the torn edge.
  • 00:01:48
    Carefully pull out the thin membranous transparent layer from the lower epidermis using a forceps.
  • 00:01:54
    Put the epidermis into the watch glass containing distilled water.
  • 00:01:58
    Take few drops of Safranin solution using a dropper and put it into another watch glass.
  • 00:02:05
    Using a brush, transfer the epidermis into the watch glass containing Safranin solution.
  • 00:02:11
    Keep the epidermis for 30 sec in Safranin solution so the peel can become stained.
  • 00:02:17
    To remove excess of stain sticking to the peel, transfer it to the watch glass containing
  • 00:02:22
    water.
  • 00:02:23
    Transfer the peel to a clean glass slide using the brush.
  • 00:02:27
    Take few drops of glycerine using a dropper and put it on the peel.
  • 00:02:32
    Using a needle, put a cover slip over the epidermis gently.
  • 00:02:36
    Drain out excess glycerine using a blotting paper.
  • 00:02:40
    Take the glass slide and place it under the compound microscope.
  • 00:02:44
    Examine the slide under the compound microscope.
  • 00:02:48
    Observations
  • 00:02:52
    The epidermis is made of uniseriate layers of cells, which have distinct cell walls,
  • 00:02:57
    a nucleus and cytoplasm, and are closely packed together.
  • 00:03:02
    The epidermal layers are broken in places.
  • 00:03:05
    These openings are the stomata.
  • 00:03:08
    Each stoma is guarded by a pair of bean shaped cells which are guard cells.
  • 00:03:14
    Precautions
  • 00:03:17
    The epidermal peel should be taken from a freshly-plucked leaf.
  • 00:03:21
    Take the epidermal from the lower surface of a leaf, as it has more stomata.
  • 00:03:26
    Always use a clean glass slide.
标签
  • Stomata
  • Epidermis
  • Guard cells
  • Microscope
  • Safranin
  • Gas exchange
  • Plant
  • Balsam leaf
  • Experiment
  • Leaf peel