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Assimilation is the process of absorption of vitamins, minerals, and other chemicals from food as part of the nutrition of an organism. In humans, this is always done with a chemical breakdown ( enzymes and acids ) and physical breakdown (oral mastication and stomach churning).
It occurs in a hypotonic environment, where water moves into the cell by osmosis and causes its volume to increase to the point where the volume exceeds the membrane's capacity and the cell bursts. The presence of a cell wall prevents the membrane from bursting, so cytolysis only occurs in animal and protozoa cells which do not have cell walls.
The equivalent process in animal cells is called crenation. The liquid content of the cell leaks out due to exosmosis. The cell collapses, and the cell membrane pulls away from the cell wall (in plants). Most animal cells consist of only a phospholipid bilayer (plasma membrane) and not a cell wall, therefore shrinking up under such conditions.
The development of cells in a syncytium (multinucleate cells) is termed syncytium cellularization. Syncytia are quite frequent in animals and plants. Syncytium cellularization occurs for instance in the embryonic development of animals and in endosperm development of plants. Here two examples:
Structure of a typical animal cell Structure of a typical plant cell. Plants, animals, fungi, slime moulds, protozoa, and algae are all eukaryotic. These cells are about fifteen times wider than a typical prokaryote and can be as much as a thousand times greater in volume.
In animals, sulfur assimilation occurs primarily through the diet, as animals cannot produce sulfur-containing compounds directly. Sulfur is incorporated into amino acids such as cysteine and methionine , which are used to build proteins and other important molecules.
Diagram showing the development of different blood cells from haematopoietic stem cell to mature cells. Haematopoiesis (/ h ɪ ˌ m æ t ə p ɔɪ ˈ iː s ɪ s, ˌ h iː m ə t oʊ-, ˌ h ɛ m ə-/; [1] [2] from Ancient Greek αἷμα (haîma) 'blood' and ποιεῖν (poieîn) 'to make'; also hematopoiesis in American English, sometimes h(a)emopoiesis) is the formation of blood cellular ...
This occurs when individual cells or groups of cells grow longer. Not all plant cells will grow to the same length. When cells on one side of a stem grow longer and faster than cells on the other side, the stem will bend to the side of the slower growing cells as a result. This directional growth can occur via a plant's response to a particular ...