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  2. Coal ball - Wikipedia

    en.wikipedia.org/wiki/Coal_ball

    A coal ball is a type of concretion, varying in shape from an imperfect sphere to a flat-lying, irregular slab.Coal balls were formed in Carboniferous Period swamps and mires, when peat was prevented from being turned into coal by the high amount of calcite surrounding the peat; the calcite caused it to be turned into stone instead.

  3. Concretion - Wikipedia

    en.wikipedia.org/wiki/Concretion

    Concretions in Torysh, Western Kazakhstan Concretions with lens shape from island in Vltava river, Prague, Czech Republic Marlstone aggregate concretion, Sault Ste. Marie, Michigan, United States A concretion is a hard and compact mass formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary ...

  4. 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 ...

  5. Ground tissue - Wikipedia

    en.wikipedia.org/wiki/Ground_tissue

    Sclerenchyma is the tissue which makes the plant hard and stiff. Sclerenchyma is the supporting tissue in plants. Two types of sclerenchyma cells exist: fibers cellular and sclereids. Their cell walls consist of cellulose, hemicellulose, and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation.

  6. Underground stem - Wikipedia

    en.wikipedia.org/wiki/Underground_stem

    Stolon - Horizontal stems that run at or just below the soil surface with nodes that root and long internodes, the ends produce new plants. When above ground they are called "runners". Tuber - An enlarged fleshy end of a stem, generally from rhizomes but often also referring to thickened roots. A number of underground stems are consumed by ...

  7. Outline of cell biology - Wikipedia

    en.wikipedia.org/wiki/Outline_of_cell_biology

    Light micrograph of a moss's leaf cells at 400X magnification. The following outline is provided as an overview of and topical guide to cell biology: . Cell biology – A branch of biology that includes study of cells regarding their physiological properties, structure, and function; the organelles they contain; interactions with their environment; and their life cycle, division, and death.

  8. Primary growth - Wikipedia

    en.wikipedia.org/wiki/Primary_growth

    Plant growth takes place in well defined plant locations. Specifically, the cell division and differentiation needed for growth occurs in specialized structures called meristems. [1] [2] These consist of undifferentiated cells (meristematic cells) capable of cell division. Cells in the meristem can develop into all the other tissues and organs ...

  9. Plant tissue culture - Wikipedia

    en.wikipedia.org/wiki/Plant_tissue_culture

    Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues, or organs under sterile conditions on a nutrient culture medium of known composition. It is widely used to produce clones of a plant in a method known as micropropagation. Different techniques in plant tissue culture may offer certain advantages ...