Search results
Results From The WOW.Com Content Network
An organism is any living thing that functions as an individual. [1] Such a definition raises more problems than it solves, not least because the concept of an individual is also difficult. Many criteria, few of them widely accepted, have been proposed to define what an organism is.
Phylogenetic tree linking all major groups of living organisms, namely the Bacteria, Archaea, and Eukarya, as proposed by Woese et al 1990, [1] with the last universal common ancestor (LUCA) shown at the root
Thus, different cells can have very different physical characteristics despite having the same genome. Morphogenesis, or the development of body form, is the result of spatial differences in gene expression. [82] A small fraction of the genes in an organism's genome called the developmental-genetic toolkit control the development of that organism.
In genetics, the phenotype (from Ancient Greek φαίνω (phaínō) 'to appear, show' and τύπος (túpos) 'mark, type') is the set of observable characteristics or traits of an organism. [ 1 ] [ 2 ] The term covers the organism's morphology (physical form and structure), its developmental processes, its biochemical and physiological ...
In biology, taxonomy (from Ancient Greek τάξις 'arrangement' and -νομία 'method') is the scientific study of naming, defining (circumscribing) and classifying groups of biological organisms based on shared characteristics. Organisms are grouped into taxa (singular: taxon), and these groups are given a taxonomic rank; groups of a given ...
An organism must be viable at all stages of its development and at all stages of its evolution. This places constraints on the evolution of development, behaviour, and structure of organisms. The main constraint, over which there has been much debate, is the requirement that each genetic and phenotypic change during evolution should be ...
Morphology of a male skeleton shrimp, Caprella mutica Morphology in biology is the study of the form and structure of organisms and their specific structural features. [1]This includes aspects of the outward appearance (shape, structure, color, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of internal parts like bones and organs, i.e. internal ...
All known living things are made up of one or more cells [13] All living cells arise from pre-existing cells by division. The cell is the fundamental unit of structure and function in all living organisms. [14] The activity of an organism depends on the total activity of independent cells. [15] Energy flow (metabolism and biochemistry) occurs ...