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The phragmosome is a sheet of cytoplasm forming in highly vacuolated plant cells in preparation for mitosis. [1] In contrast to animal cells, plant cells often contain large central vacuoles occupying up to 90% of the total cell volume and pushing the nucleus against the cell wall. In order for mitosis to occur, the nucleus has to move into the ...
These eventually become the cytoplasmic connections between cells. At the formation site, the wall is not thickened further, and depressions or thin areas known as pits are formed in the walls. Pits normally pair up between adjacent cells. Plasmodesmata can also be inserted into existing cell walls between non-dividing cells (secondary ...
In 1903, Nikolai K. Koltsov proposed that the shape of cells was determined by a network of tubules that he termed the cytoskeleton. The concept of a protein mosaic that dynamically coordinated cytoplasmic biochemistry was proposed by Rudolph Peters in 1929 [12] while the term (cytosquelette, in French) was first introduced by French embryologist Paul Wintrebert in 1931.
A plant cell wall was first observed and named (simply as a "wall") by Robert Hooke in 1665. [3] However, "the dead excrusion product of the living protoplast" was forgotten, for almost three centuries, being the subject of scientific interest mainly as a resource for industrial processing or in relation to animal or human health.
Gk plastós formed, molded) and filled with cell sap. Also called the vacuolar membrane, the tonoplast is the cytoplasmic membrane surrounding a vacuole, separating the vacuolar contents from the cell's cytoplasm. As a membrane, it is mainly involved in regulating the movements of ions around the cell, and isolating materials that might be ...
The cytoplasm describes all the material within a eukaryotic or prokaryotic cell, enclosed by the cell membrane, including the organelles [1] and excluding the nucleus in eukaryotic cells. The material inside the nucleus of a eukaryotic cell and contained within the nuclear membrane is termed the nucleoplasm .
Cells can be up to 10 cm long, and are separated by a small septum. [17] Small holes in the septum allow cytoplasm and cytoplasmic contents to flow from cell to cell. Osmotic pressure gradients occur through the length of the cell to drive this cytoplasmic flow. Flows contribute to growth and the formation of cellular subcompartments. [17] [18]
The microtubule-organizing center (MTOC) is a structure found in eukaryotic cells from which microtubules emerge. MTOCs have two main functions: the organization of eukaryotic flagella and cilia and the organization of the mitotic and meiotic spindle apparatus, which separate the chromosomes during cell division.