Jump to content

Portal:Biology

From Wikipedia, the free encyclopedia
(Redirected from P:BIO)

The Biology Portal

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 and living organisms. It is a broad natural science that encompasses a wide range of fields and unifying principles that explain the structure, function, growth, origin, evolution, and distribution of life. Central to biology are five fundamental themes: the cell as the basic unit of life, genes and heredity as the basis of inheritance, evolution as the driver of biological diversity, energy transformation for sustaining life processes, and the maintenance of internal stability (homeostasis).

Biology examines life across multiple levels of organization, from molecules and cells to organisms, populations, and ecosystems. Subdisciplines include molecular biology, physiology, ecology, evolutionary biology, developmental biology, and systematics, among others. Each of these fields applies a range of methods to investigate biological phenomena, including observation, experimentation, and mathematical modeling. Modern biology is grounded in the theory of evolution by natural selection, first articulated by Charles Darwin, and in the molecular understanding of genes encoded in DNA. The discovery of the structure of DNA and advances in molecular genetics have transformed many areas of biology, leading to applications in medicine, agriculture, biotechnology, and environmental science.

Life on Earth is believed to have originated over 3.7 billion years ago. Today, it includes a vast diversity of organisms—from single-celled archaea and bacteria to complex multicellular plants, fungi, and animals. Biologists classify organisms based on shared characteristics and evolutionary relationships, using taxonomic and phylogenetic frameworks. These organisms interact with each other and with their environments in ecosystems, where they play roles in energy flow and nutrient cycling. As a constantly evolving field, biology incorporates new discoveries and technologies that enhance the understanding of life and its processes, while contributing to solutions for challenges such as disease, climate change, and biodiversity loss. (Full article...)

The structure of the DNA double helix (type B-DNA). The atoms in the structure are colour-coded by element and the detailed structures of two base pairs are shown in the bottom right.
Deoxyribonucleic acid (/dˈɒksɪˌrbnjˌklɪk, -ˌkl-/ ; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of all known organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids. Alongside proteins, lipids and complex carbohydrates (polysaccharides), nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life.

The two DNA strands are known as polynucleotides as they are composed of simpler monomeric units called nucleotides. Each nucleotide is composed of one of four nitrogen-containing nucleobases (cytosine [C], guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and a phosphate group. The nucleotides are joined to one another in a chain by covalent bonds (known as the phosphodiester linkage) between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules (A with T and C with G), with hydrogen bonds to make double-stranded DNA. The complementary nitrogenous bases are divided into two groups, the single-ringed pyrimidines and the double-ringed purines. In DNA, the pyrimidines are thymine and cytosine; the purines are adenine and guanine. (Full article...)

List of selected articles

Selected picture - show another

Two Centrosauri in an artist's impression of male combat.

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

George Ledyard Stebbins Jr. (January 6, 1906 – January 19, 2000) was an American botanist and geneticist who is widely regarded as one of the leading evolutionary biologists of the 20th century. Stebbins received his Ph.D. in botany from Harvard University in 1931. He went on to the University of California, Berkeley, where his work with E. B. Babcock on the genetic evolution of plant species, and his association with a group of evolutionary biologists known as the Bay Area Biosystematists, led him to develop a comprehensive synthesis of plant evolution incorporating genetics.

His most important publication was Variation and Evolution in Plants, which combined genetics and Darwin's theory of natural selection to describe plant speciation. It is regarded as one of the main publications which formed the core of the modern synthesis and still provides the conceptual framework for research in plant evolutionary biology; according to Ernst Mayr, "Few later works dealing with the evolutionary systematics of plants have not been very deeply affected by Stebbins' work." He also researched and wrote widely on the role of hybridization and polyploidy in speciation and plant evolution; his work in this area has had a lasting influence on research in the field. (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?

Things you can do

Biology portals

Categories

Select [►] to view subcategories

More topics

WikiProjects

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject: