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The biosphere (which is technically a spherical shell) is virtually a closed system with regard to matter, [1] with minimal inputs and outputs. Regarding energy, it is an open system, with photosynthesis capturing solar energy at a rate of around 100 terawatts. [2] By the most general biophysiological definition, the biosphere is the global ...
686465. Anatomical terminology. [edit on Wikidata] The cell is the basic structural and functional unit of all forms of life. Every cell consists of cytoplasm enclosed within a membrane; many cells contain organelles, each with a specific function. The term comes from the Latin word cellula meaning 'small room'.
Bernal coined the term biopoiesis in 1949 to refer to the origin of life. [33] In 1967, he suggested that it occurred in three "stages": the origin of biological monomers; the origin of biological polymers; the evolution from molecules to cells; Bernal suggested that evolution commenced between stages 1 and 2.
The biosphere is postulated to have developed, from the origin of life onwards, at least some 3.5 billion years ago. [74] The earliest evidence for life on Earth includes biogenic graphite found in 3.7 billion-year-old metasedimentary rocks from Western Greenland [ 69 ] and microbial mat fossils found in 3.48 billion-year-old sandstone from ...
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 ...
The ancestry of each present day cell presumably traces back, in an unbroken lineage for over 3 billion years to the origin of life. It is not actually cells that are immortal but multi-generational cell lineages. [30] The immortality of a cell lineage depends on the maintenance of cell division potential.
Evolution of cells refers to the evolutionary origin and subsequent evolutionary development of cells. Cells first emerged at least 3.8 billion years ago [ 1 ] [ 2 ] [ 3 ] approximately 750 million years after Earth was formed.
The origin of the eukaryotic cell, or eukaryogenesis, is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The last eukaryotic common ancestor (LECA) is the hypothetical origin of all living eukaryotes, [ 70 ] and was most likely a biological population , not a single ...