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Learn about tissues, organs, and organ systems in the human body with Khan Academy's free educational resources.
Cell parts and functions (article) | Khan Academy
Review your understanding of cell parts and functions in this free article aligned to NGSS standards. Key points: All cells have a cell membrane that separates the inside and the outside of the cell, and controls what goes in and comes out.
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Plasma membrane and cytoplasm - Khan Academy
The plasma membrane is the border between the interior and exterior of a cell. As such, it controls passage of various molecules—including sugars, amino acids, ions, and water—into and out of the cell. How easily these molecules can cross the membrane depends on their size and polarity.
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Learn about the phases of mitosis and their significance in cell division on Khan Academy.
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All blood cells start off as hematopoietic stem cells, and then specialize (differentiate) into myeloid cells (erythrocytes, megakaryocytes, monocytes, neutrophils, basophils, or eosinophils) or lymphoid cells (T-lymphocytes and B-lymphocytes).
Signal transduction pathway | Cell signaling (article) | Khan Academy
Learn how signals are relayed inside a cell starting from the cell membrane receptor. The chains of molecules that relay intracellular signals are known as intracellular signal transduction pathways.
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Learn about human embryogenesis, from zygote formation to the development of germ layers and organ systems.
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Cell: the unit of life: Quiz 1; Cell structures and their functions; Eukaryotic cell structures; Cell: the unit of life: Unit test; Unit 3 Unit 3: Biomolecules. ... Unit 4 Unit 4: Tissues (Structural organization in animals) Epithelial tissue; Connective tissue; Muscular tissue and neural tissue;
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La membrana plasmática y el citoplasma son componentes esenciales de las células que regulan el transporte de sustancias y mantienen la estructura celular.