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Event 2500 Ma Great Oxidation Event led by cyanobacteria's oxygenic photosynthesis. [41] Commencement of plate tectonics with old marine crust dense enough to subduct. [28] 2023 Ma Formation of the Vredefort impact structure, one of the largest and oldest verified impact structures on Earth. The crater is estimated to have been between 170 ...
Biological organisation is the organisation of complex biological structures and systems that define life using a reductionistic approach. [1] The traditional hierarchy, as detailed below, extends from atoms to biospheres. The higher levels of this scheme are often referred to as an ecological organisation concept, or as the field, hierarchical ...
Biological organization spans several scales and are determined based different structures depending on what the system is. [1] Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the ...
Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life. Growth: maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.
With the development of these three techniques, the field of structural biology expanded and also became a branch of molecular biology, biochemistry, and biophysics concerned with the molecular structure of biological macromolecules (especially proteins, made up of amino acids, RNA or DNA, made up of nucleotides, and membranes, made up of ...
How an individual organism's structures function Ontogeny (development) Developmental explanations for changes in individuals, from DNA to their current form Mechanism (causation) Mechanistic explanations for how an organism's structures work Ultimate (evolutionary) view Why a species evolved the structures (adaptations) it has Phylogeny ...
A life form (also spelled life-form or lifeform) is an entity that is living, [1] [2] such as plants , animals , and fungi . It is estimated that more than 99% of all species that ever existed on Earth, amounting to over five billion species, [3] are extinct. [4] [5] Earth is the only celestial body known to harbor life forms. No form of ...
Turrill (1935) has suggested that while accepting the older invaluable taxonomy, based on structure, and conveniently designated "alpha", it is possible to glimpse a far-distant taxonomy built upon as wide a basis of morphological and physiological facts as possible, and one in which "place is found for all observational and experimental data ...