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Illustration of a eukaryotic cell membrane Comparison of a eukaryotic vs. a prokaryotic cell membrane. The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extracellular space).
The cell cycle in eukaryotes: I = Interphase, M = Mitosis, G 0 = Gap 0, G 1 = Gap 1, G 2 = Gap 2, S = Synthesis, G 3 = Gap 3. Cell division is the process by which a parent cell divides into two daughter cells. [ 1 ] Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome (s) before ...
Pangaea is the most recent supercontinent to have existed and the first to be reconstructed by geologists. Origin of the concept. Alfred Wegener c. 1924–1930World map of Pangaea created by Alfred Wegener to illustrate his concept. The name "Pangaea" is derived from Ancient Greekpan(πᾶν, "all, entire, whole") and Gaiaor Gaea (Γαῖα ...
Symbiogenesis (endosymbiotic theory, or serial endosymbiotic theory[ 2 ]) is the leading evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms. [ 3 ] The theory holds that mitochondria, plastids such as chloroplasts, and possibly other organelles of eukaryotic cells are descended from formerly free-living prokaryotes ...
The cell cycle, or cell-division cycle, is the sequential series of events that take place in a cell that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA ( DNA replication ) and some of its organelles , and subsequently the partitioning of its cytoplasm, chromosomes and other ...
Fluid mosaic model of a cell membrane. The fluid mosaic model explains various characteristics regarding the structure of functional cell membranes. According to this biological model, there is a lipid bilayer (two molecules thick layer consisting primarily of amphipathic phospholipids) in which protein molecules are embedded.
They split in two groups, with one returning to Gondwana (and stayed there after Pangaea split) while the other staying in Laurasia (until further descendants switched to Gondwana starting from the Jurassic). In the early Eocene a peak in global warming led to a pan-Arctic fauna with alligators and amphibians present north of the Arctic Circle.
The eukaryotic cell seems to have evolved from a symbiotic community of prokaryotic cells. DNA-bearing organelles like mitochondria and chloroplasts are remnants of ancient symbiotic oxygen-breathing bacteria and cyanobacteria, respectively, where at least part of the rest of the cell may have been derived from an ancestral archaean prokaryote ...