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Magnitude (astronomy)

The apparent magnitude of a celestial object is a number that measures its brightness as seen by an observer on Earth. The brighter an object appears, the lower its magnitude value. The Sun, at apparent magnitude of −27, is the brightest object i ...

                                               

Radio astronomy

Radio astronomy is astronomy which studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was made in the 1930s. Karl Jansky found radiation coming from the Milky Way. Later, other sources o ...

                                               

Sagittarius Window Eclipsing Extrasolar Planet Search

The Sagittarius Window Eclipsing Extrasolar Planet Search, or SWEEPS, was an astronomical survey. It was carried out in 2006. SWEEPS used the Hubble Space Telescope to look at 180.000 stars for seven days to find extrasolar planets.

                                               

Extraterrestrial sky

In astronomy, an extraterrestrial sky is a view of outer space from the surface of a planet other than Earth. The only extraterrestrial sky that has been directly observed and photographed by astronauts is that of the Moon. The skies of Venus, Ma ...

                                               

Spectrograph

A spectrograph is an instrument that breaks up a wave into a frequency spectrum. These could be sound, light or radio waves. For example the frequency spectrum of light is the brightness and the amount of each colour. There are several kinds of m ...

                                               

Star chart

A star chart is a graphic device or diagram which shows the night sky as seen from Earth. They are one of the oldest types of written or carved communication. There is a claim for a prehistoric carving as the first known star chart, but the evide ...

                                               

Three-body problem

The three-body problem is a problem in the field of physics that experts find interesting. The goal is to find how three things move when they attract each other with gravity. It would be for instance the problem of the movement of the Sun, the E ...

                                               

Zenith

In astronomy, the zenith is a point "above" a particular location, in the sky. "Above" means in the opposite direction of gravity at that location. The zenith is the opposite of the nadir. The nadir is in the direction the direction that gravity ...

                                               

Ageing

Ageing is the changes that happen in an individual over time. In humans, ageing is several physical and psychological changes. Senescence is the biological process which leads to ageing. There have been many attempts to answer the question: why d ...

                                               

Antinatalism

Antinatalism, or anti-natalism, is a philosophical stance and social movement that gives a negative value to starting life. Antinatalists argue that humans should stop making kids because it is morally bad. People who believe that making kids is ...

                                               

Behavioural Responses to Stress in Animals

Real or perceived threat in the environment, elicits stress response in animals, which disrupts the internal constant environment of the animal. There are different kinds of stressors that animals can be exposed to, and there are different kinds ...

                                               

Biological pigment

A biological pigment is a pigment which gives an individual life form its colour. Plants and animals have different reasons for being different colours, and their colours serve certain purposes. Chlorophyll in plants is a green pigment used to co ...

                                               

Biophysical chemistry

Biophysical chemistry is the study of biological systems. It looks for explanations of the various phenomena in biological systems in terms of either the molecules that make up the system or the supra-molecular structure of these systems. Biophys ...

                                               

Chemical biology

Chemical biology is a science that combines the fields of chemistry and biology. It involves the application of chemical techniques and tools, often compounds produced through synthetic chemistry, to the study and manipulation of biological syste ...

                                               

Decomposition

Decomposition, or rotting, is what happens to living things when they die. It also happens to organic material of any kind, such as foodstuffs. The reason it happens is that organic molecules are stores of building blocks and energy. Whatever bre ...

                                               

Detritus

In biology, detritus is non-living particules of organic origin. Typically, it includes the bodies or fragments of dead organisms as well as faecal material. Detritus is typically colonized by communities of fungi and microorganisms which act to ...

                                               

Field research

Field research is research done in natural surroundings. It is used in biology to contrast with research done in the laboratory. Field research is defined as a qualitative method of data collection that aims to observe, interact and understand pe ...

                                               

Flora and fauna of Mexico

Plant and animal life differs sharply with Mexicos varied climate and topography. The coastal plains are covered with a tropical rain forest, which merges into subtropical and temperate growth as the plateau is ascended. In the northern states th ...

                                               

Freshwater biology

Freshwater biology is the study of plants and animals that live in fresh water. This includes rivers, lakes, ponds, marshes and other bodies of water. It is part of the branch of science called Limnology. Much freshwater biology takes place in ma ...

                                               

Function (biology)

Function in biology is what a part of the body or cell does in relation to the whole. It is the reason some part or process occurred in a system which evolved by natural selection. A similar definition is "the function of a component in an organi ...

                                               

Habit (biology)

The way plants grow makes their shape of habit. This is the way we can tell trees apart even at a distance. The shape of a willow tree or a poplar is very distinct. It is made during growth. Bacteria and fungi also have very distinct types of gro ...

                                               

Hermaphrodite

Hermaphrodite is a term which comes from Hermaphroditus, the son of Hermes and Aphrodite. It is used as a scientific term in biology. In zoology, an animal which can produce both sperm and ova is a hermaphrodite. As an example, most earthworms ar ...

                                               

Heterotroph

A heterotroph is an organism that requires organic substrates to get its carbon for growth and development.

                                               

Homology

A homologous trait is any characteristic which is derived by evolution from a common ancestor. This is contrasted to analogous traits: similarities between organisms that were evolved separately. The term existed before 1859, but got its modern m ...

                                               

Human biology

Human biology is an area of study that is part of biology, biological anthropology, and medicine which looks at humans; it is closely related to primate biology, and a number of other areas. Human biology research includes: Genetic differences ac ...

                                               

Land bridge

A land bridge is a term in biogeography. It is a narrow land connection between otherwise separate areas, sometimes called an isthmus. Its significance is that animals and plants may cross over it when the sea level is lower. They cannot easily c ...

                                               

Life cycle

Life cycle means the stages a living thing goes through during its life. In some cases the process is slow, and the changes are gradual. Humans have various stages of growth during their lives, such as zygote, embryo, child and adult. The change ...

                                               

List of sequenced animal genomes

Renilla muelleri, an octocoral 2017, 2019 Pocillopora damicornis, cauliflower coral 2018 Clytia hemisphaerica, Hydrozoa jellyfish 2019 Cassiopea xamachana Scyphozoa 2019 Aurelia aurita, moon jellyfish 2019 Acropora digitifera, a coral 2011 Rhopil ...

                                               

List of sequenced Deuterostomia genomes

Subclass Prototheria, Order Monotremata, Family Ornithorhynchidae Ornithorhynchus anatinus, platypus 2007 Order Didelphimorphia, Family Didelphidae opossums Infraclass Metatheria marsupials Monodelphis domestica, gray short-tailed opossum 2007 Su ...

                                               

Marine biology

Marine biology is the study of any living plant or animal in the sea. Marine biologists are the people who study it. Like other scientists, marine biologists must know a lot about the creatures they are studying. They also must understand how the ...

                                               

Mechanistic paradigm

The mechanistic paradigm, also known as the Newtonian paradigm, assumes that things in the environment around humans are more like machines than like life. It was more common in the 19th century. This is a set of loosely related beliefs that affe ...

                                               

Morphallaxis

Morphallaxis is the when some living things regenerate or regrow tissue after the original tissue dies. The word comes from the Greek allazein, which means to exchange. For example, if a Cnidarian hydra, a microscopic animal, is cut in half, two ...

                                               

Natural history

Natural history is the study of plants and animals in the wild, and the environments they live in. This includes the geology of the places in which they live. The work of naturalists is observation, interpretation, collecting and classification, ...

                                               

Nucleus (brain)

A nucleus in anatomy is a brain structure. It is a compact cluster of neurons. It is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. The same kind o ...

                                               

Oestrogen

Oestrogen is a group of female hormones. It includes oestrone, oestradiol, and oestriol. Oestradiol is the most important oestrogen. Oestrogen is mainly secreted by the ovary, a small amount by the liver, adrenal cortex, and breast. In pregnancy, ...

                                               

Paleobiology

Paleobiology is a branch of science which studies animals, plants and microbes buried in rock. These stoney items are called fossils. Paleobiology combines biology with the study of these fossils. There are several branches of paleobiology: Evolu ...

                                               

Parencyma

Parenchyma forms the bulk of plant ground tissue, where they may be specialised to function in photosynthesis, storage, or transport. Parenchyma is integral to vascular tissue, where it provides a route of exchange for materials within and betwee ...

                                               

Pathogen

A pathogen is an infectious thing, such as a virus, bacteria, fungi or parasite, which causes a disease. This ability is called pathogenicity. The body has many ways to defend against some of the common pathogens such as Pneumocystis in the form ...

                                               

Recognition signal

A recognition signal is a signal where a person, a ship, an airplane or something else is recognized. They can be used during war or can be used to help the police recognize each other during undercover operations. It can also be used in biology ...

                                               

Saprophyte

A saprophyte or saprotroph is an organism which gets its energy from dead and decaying organic matter. This may be decaying pieces of plants or animals. This means that saprophytes are heterotrophs. They are consumers in the food chain. This is t ...

                                               

Taxidermy

Taxidermy is act of taking the skin of an animals and preserving it, by putting it on a fake body. If you perform taxidermy, you taxiderm. Taxidermed animals can be mounted and put on display, sometimes in a museum or a home. People who taxidermy ...

                                               

Wildlife of Afghanistan

Afghanistan is a country that has lots of amazing animals. Many of the large mammals in Afghanistan are threatened. These include the snow leopard, Marco Polo sheep, Siberian musk deer, markhor, urial, and the Asiatic black bear. Most of the Marc ...

                                               

Chemical element

A chemical element is a substance that contains only one type of atom, which is the smallest particle of an element. Atoms are made up of protons, neutrons, and electrons. The number of protons in an atom is called the atomic number. For example, ...

                                               

Chemistry

Before 1600, people studied substances to figure out how to do things such as turn lead into gold, but no one managed to do that. This was called alchemy. After 1600, using the scientific method alchemists became chemists. Chemists separated the ...

                                               

Absorption

Absorption is a condition in which something takes in another substance. It is a physical or chemical phenomenon or process, in which atoms, molecules, or ions enter in the inner part of a gas, liquid, or solid material. This is a different proce ...

                                               

Alkali

In chemistry, an alkali is an aqueous solution with a pH value of more than 7. The word Alkali comes from the Arabic qali meaning from the ashes since ashes mixed with water used as cleaning products are made of alkali materials An alkali is wher ...

                                               

Allotropy

Allotropy is when a chemical element can exist in two or more different forms in the same physical state or phase. These different forms are called allotropes. Therefore, an allotrope is a different structure in which an element appears. This hap ...

                                               

Amount of substance

Amount of substance is a quantity defined by standards to measures the size a group of individual elementary entities, such as atoms, molecules and electrons, along with other particles. The International System of Units defines the amount of sub ...

                                               

Anaerobic digestion

Anaerobic digestion is the way microorganisms break down organic matter without oxygen. This process can happen naturally, but it is called anaerobic digestion only if it is supported and contained. An anaerobic digester is an industrial system t ...

                                               

Antiknock agent

An antiknock agent is added to gasoline. It reduces engine knocking and increase the fuels octane rating. Gasoline is a fuel mixture. High compression internal combustion engines place gasoline under great pressure. The pressure can cause the gas ...