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Portal:Biology

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Introduction

A panoramic view from a ridge located between Segla and Hesten mountain summits in the island of Senja, Troms, Norway in 2014
A panoramic view from a ridge located between Segla and Hesten mountain summits in the island of Senja, Troms, Norway in 2014

Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary information encoded in genes, which can be transmitted to future generations. Another major theme is evolution, which explains the unity and diversity of life. Energy processing is also important to life as it allows organisms to move, grow, and reproduce. Finally, all organisms are able to regulate their own internal environments.

Biologists are able to study life at multiple levels of organization, from the molecular biology of a cell to the anatomy and physiology of plants and animals, and evolution of populations. Hence, there are multiple subdisciplines within biology, each defined by the nature of their research questions and the tools that they use. Like other scientists, biologists use the scientific method to make observations, pose questions, generate hypotheses, perform experiments, and form conclusions about the world around them.

Life on Earth, which emerged more than 3.7 billion years ago, is immensely diverse. Biologists have sought to study and classify the various forms of life, from prokaryotic organisms such as archaea and bacteria to eukaryotic organisms such as protists, fungi, plants, and animals. These various organisms contribute to the biodiversity of an ecosystem, where they play specialized roles in the cycling of nutrients and energy through their biophysical environment. (Full article...)

An organism is defined in a medical dictionary as any living thing that functions as an individual. 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 is an organism. Among the commonest is that an organism has autonomous reproduction, growth, and metabolism. This would exclude viruses, despite that fact that they evolve like organisms. Other problematic cases include colonial organisms; a colony of eusocial insects is organised adaptively, and has germ-soma specialisation, with some insects reproducing, others not, like cells in an animal's body. The body of a siphonophore, a jelly-like marine animal, is composed of organism-like zooids, but the whole structure looks and functions much like an animal such as a jellyfish, the parts collaborating to provide the functions of the colonial organism.

The evolutionary biologists David Queller and Joan Strassmann state that "organismality", the qualities or attributes that define an entity as an organism, has evolved socially as groups of simpler units (from cells upwards) came to cooperate without conflicts. They propose that cooperation should be used as the "defining trait" of an organism. This would treat many types of collaboration, including the fungus/alga partnership of different species in a lichen, or the permanent sexual partnership of an anglerfish, as an organism. (Full article...)
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Mayflies are insects assigned to the Order Ephemeroptera. They are related to dragonflies and damselflies. Their development takes place in freshwater and typically takes a year. During that time, they are known as "nymphs". The adults are short-lived, from a few hours to a few days depending on the species. About 2,500 species are known worldwide. Depicted here is a female subimago of the March Brown, Rhithrogena germanica, which is a faunistic rarity and on the red list of endangered species.
The plant shown is a horsetail, Equisetum arvense.

Major topics

History History of biology | timeline of biology and organic chemistry | history of ecology | history of evolutionary thought | history of geology | history of model organisms | history of molecular biology | history of paleontology
Overview Biology | science | life | properties (adaptationenergy processinggrowthorderregulationreproduction, and response to environment) | hierarchy of life (atommoleculeorganellecelltissueorganorgan systemorganismpopulationcommunityecosystembiosphere) | reductionistic | emergent property | mechanistic | scientific method | theory | law | peer review | biology journals
Chemical basis Matter | elements | compounds | atoms | molecules | chemical bonds | carbon | organic compounds | macromolecules | carbohydrate | protein | protein structure | protein folding | lipid | DNA | RNA
Cells Prokaryote | eukaryote | cell wall | cell membrane | cytoskeleton | mitochondrion | chloroplast | nucleus | endoplasmic reticulum | Golgi apparatus | cell cycle | mitosis | metabolism | cell signaling | protein targeting | metabolism | enzyme | glycolysis | citric acid cycle | electron transport chain | oxidative phosphorylation |photosynthesis |meiosis  | mitosis
Genetics (Intro) Classical genetics | mendelian inheritance | gene | phenotype | genotype | ploidy | alternation of generations | molecular genetics | gene expression | gene regulation | genome | karyotype | DNA replication | transcription | translation | recombination | chromosome | epigenetics | splicing | mutation | genetic fingerprint | chromatin | ecological genetics | population genetics | quantitative genetics
Evolution (Intro)  | omne vivum ex ovo | Natural selection | genetic drift | sexual selection | speciation | mutation | gene flow | evolution of sex | biogeography | cladistics | species | extinction | tree of life | phylogenies | three-domain system
Diversity Bacteria | archaea | plants | angiosperms | fungi | protists | Animals | deuterostome | insects | molluscs | nematodes | parasitism | Primate | mammal | vertebrate | craniata | chordate | viruses
Plant form and function Epidermis | flower | ground tissue  | leaf | phloem | plant stem | root | shoot | vascular plant | vascular tissue | xylem
Animal form and function Tissues | fertilization | embryogenesis | gastrulation | neurulation | organogenesis | differentiation | morphogenesis | metamorphosis | ontogeny  | Development | senescence  | reproduction | oogenesis | spermatogenesis
Ecology Ecosystem | biomass | food chain | indicator species | habitat | species distribution | Gaia theory | metapopulation  | life cycle | Life history | altricial - precocial | sex ratio | altruism | cooperation - foraging | learning | parental care | sexual conflict | territoriality | biosphere | climate change | conservation | biodiversity | nature reserve | edge effect | allee effect | corridor | fragmentation | pollution | invasive species | in situ - ex situ | seedbank
Research methods Laboratory techniques | Genetic engineering | transformation | gel electrophoresis | chromatography | centrifugation | cell culture | DNA sequencing | DNA microarray | green fluorescent protein | vector | enzyme assay | protein purification | Western blot | Northern blot | Southern blot | restriction enzyme | polymerase chain reaction | two-hybrid screening | in vivo - in vitro - in silico | Field techniques | Belt transect | mark and recapture | species discovery curve
Branches Anatomy | biotechnology | botany | cell biology | ecology | evolutionary biology | genetics | marine biology | microbiology | molecular biology | mycology | neuroscience | paleontology | phycology | physiology | protistology | virology | zoology
Awards Nobel Prize in Physiology or Medicine
See also Template:History of biology

Selected biography - show another

Wallace in 1895

Alfred Russel Wallace OM FRS (8 January 1823 – 7 November 1913) was an English naturalist, explorer, geographer, anthropologist, biologist and illustrator. He independently conceived the theory of evolution through natural selection; his 1858 paper on the subject was published that year alongside extracts from Charles Darwin's earlier writings on the topic. It spurred Darwin to set aside the "big species book" he was drafting and quickly write an abstract of it, which was published in 1859 as On the Origin of Species.

Wallace did extensive fieldwork, starting in the Amazon River basin. He then did fieldwork in the Malay Archipelago, where he identified the faunal divide now termed the Wallace Line, which separates the Indonesian archipelago into two distinct parts: a western portion in which the animals are largely of Asian origin, and an eastern portion where the fauna reflect Australasia. He was considered the 19th century's leading expert on the geographical distribution of animal species, and is sometimes called the "father of biogeography", or more specifically of zoogeography. (Full article...)

General images - load new batch

The following are images from various biology-related articles on Wikipedia.
  • ... that one of the smallest fish, the Philippine goby, can only grow between 1 and 1.5 cm?
  • ...that the largest flower, Rafflesia has a very foul odor?
  • ... that mesoporous silica nanoparticles are prepared by the Stöber process and are used in preparing biosensors and delivering medications to within cellular structures?

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