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  2. Palisade cell - Wikipedia

    en.wikipedia.org/wiki/Palisade_cell

    Palisade cells contain a high concentration of chloroplasts, particularly in the upper portion of the cell, making them the primary site of photosynthesis in the leaves of plants that contain them. Their vacuole also aids in this function: it is large and central, pushing the chloroplasts to the edge of the cell, maximising the absorption of ...

  3. Tears - Wikipedia

    en.wikipedia.org/wiki/Tears

    The functions of tears include lubricating the eyes (basal tears), removing irritants (reflex tears), and also aiding the immune system. [3] Tears also occur as a part of the body's natural pain response. [4] Emotional secretion of tears may serve a biological function by excreting stress-inducing hormones built up through times of emotional ...

  4. Ecosystem respiration - Wikipedia

    en.wikipedia.org/wiki/Ecosystem_respiration

    The two main processes that contribute to ecosystem respiration are photosynthesis and cellular respiration. Photosynthesis uses carbon-dioxide and water, in the presence of sunlight to produce glucose and oxygen whereas cellular respiration uses glucose and oxygen to produce carbon-dioxide, water, and energy.

  5. Plant cell - Wikipedia

    en.wikipedia.org/wiki/Plant_cell

    Structure of a plant cell. Plant cells are the cells present in green plants, photosynthetic eukaryotes of the kingdom Plantae.Their distinctive features include primary cell walls containing cellulose, hemicelluloses and pectin, the presence of plastids with the capability to perform photosynthesis and store starch, a large vacuole that regulates turgor pressure, the absence of flagella or ...

  6. Cell (biology) - Wikipedia

    en.wikipedia.org/wiki/Cell_(biology)

    Cells are broadly categorized into two types: eukaryotic cells, which possess a nucleus, and prokaryotic cells, which lack a nucleus but have a nucleoid region. Prokaryotes are single-celled organisms such as bacteria , whereas eukaryotes can be either single-celled, such as amoebae , or multicellular , such as some algae , plants , animals ...

  7. Photophosphorylation - Wikipedia

    en.wikipedia.org/wiki/Photophosphorylation

    This word is taken from two Greek words, photos, which means light, and synthesis, which in chemistry means making a substance by combining simpler substances. So, in the presence of light, synthesis of food is called 'photosynthesis'. Noncyclic photophosphorylation through light-dependent reactions of photosynthesis at the thylakoid membrane.

  8. Photosynthesis system - Wikipedia

    en.wikipedia.org/wiki/Photosynthesis_System

    Photosynthesis systems function by measuring gas exchange of leaves. Atmospheric carbon dioxide is taken up by leaves in the process of photosynthesis, where CO 2 is used to generate sugars in a molecular pathway known as the Calvin cycle. This draw-down of CO 2 induces more atmospheric CO 2 to diffuse through stomata into the air spaces of the ...

  9. Chloroplast - Wikipedia

    en.wikipedia.org/wiki/Chloroplast

    Chloroplasts, containing thylakoids, visible in the cells of Ptychostomum capillare, a type of moss. A chloroplast (/ ˈ k l ɔːr ə ˌ p l æ s t,-p l ɑː s t /) [1] [2] is a type of organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells.