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principle in Biological Definition

Hardy-Weinberg principle

... The Hardy–Weinberg principle ( HWP ) (also Hardy–Weinberg equilibrium ... homozygote to be q 2 . The Hardy–Weinberg principle is an expression of the notion of a population in "genetic equilibrium" and is a basic principle of population genetics . Contents ...

Natural selection

... Scope of natural selection 4 History of the principle 5 Impact of the idea 6 See also 7 ... and are being, evolved." History of the principle Charles Darwin's discovery of the principle of natural selection, as his explanation for the ...

Biology

... biochemistry, cells and the genetic code 1.2 Evolution: the central principle of biology 1.3 Diversity: the variety of living organisms 1.4 ... stages and include similar genes . Evolution: the central principle of biology Main article: Evolution One of the central, organizing ...

Competitive exclusion principle

... The competitive exclusion principle , sometimes referred to as Gause's Law of competitive exclusion or just ... of the second competitor in the long run. The competitive exclusion principle is a theoretical concept that follows from abstract mathematical modeling ...

Charles Darwin

... 19 April 1882 ) was an English naturalist whose revolutionary theory laid the foundation for both the modern theory of evolution and the principle of common descent by proposing natural selection as a mechanism. He published this proposal in 1859 in the book The Origin of Species , ...

Cladistics

... even when the appearance of organisms makes it otherwise difficult. When equivalent possibilities turn up, one is usually chosen based on the principle of parsimony : the most compact arrangement is likely the best (a variation of Occam's razor ). Another approach, particularly useful in molecular ...

Diabetes mellitus

... meter suits all patients and it is a specific matter of choice for the patient to find a meter that they personally find comfortable to use. The principle of the devices is the virtually the same, a small blood sample is collected by the patient by self-production using a lancing device (a sterile ...

Dialysis

... infection. The effluent is drained into a toilet, and the various dialysis supplies are discarded with normal garbage. Hemodialysis The principle of hemodialysis (UK: haemodialysis) is somewhat different. It works by having the blood flow along one side of a semipermeable membrane , with the ...

Genetics

... 1944 Oswald Theodore Avery , Colin McLeod and Maclyn McCarty isolate DNA as the genetic material (at that time called transforming principle ) 1950 Erwin Chargaff shows that the four nucleotides are not present in nucleic acids in stable proportions, but that some general rules ...

Homeostasis

... or stopping. Multicellular organisms require a homeostatic internal environment , in order to live ; many environmentalists believe this principle also applies to the external environment. Many ecological , biological , and social systems are homeostatic. They oppose change to maintain ...

Insulin

... from carbohydrate eaten at the same time. As well, exercise reduces the need for insulin even when all other factors remain the same. It is in principle impossible to know for certain how much insulin (and which type) is needed to 'cover' a particular meal in order to achieve a reasonable blood ...

Konrad Lorenz

... Heinroth . He studied instinctive behaviour in animals , especially in greylag geese and jackdaws . Working with geese, he rediscovered the principle of imprinting (originally reported by Douglas Spalding in the 19th century) in the behaviour of nidifugous birds, and his writings led to its ...

Mendelian inheritance

... laws of Mendelian inheritance. Mendel's law of independent assortment Also known as Mendel's Second Law The most important principle of Mendel's law of independent assortment is that the emergence of one trait will not affect the emergence of another. While his experiments mixing ...

Microscope

... the microscope to the attention of biologists, even though simple magnifying lenses were already being produced in the 1500's, and the magnifying principle of water-filled glass bowls had been described by the Romans (Seneca). Van Leeuwenhoek's home-made microscopes were actually very small simple ...

Molecular biology

... Gel electrophoresis Main article: Gel electrophoresis Gel electrophoresis is one of the principal tools of molecular biology. The basic principle is that DNA, RNA, and proteins can all be separated using an electric field. In agarose gel electrophoresis , DNA and RNA can be separated based on ...

Nutrition

... of food energy consumed: this was first systematically investigated in the seminal study by Weidruch et al (1986). A simplistic pursuit of this principle of caloric restriction followed, involving research into longevity of those who simply reduced their food energy intake. Perhaps not suprisingly, ...

Origin of life

... we know it on Earth, and may give clues as to how life originates. Complex systems See also Category:Origin of life Anthropic principle Biogenesis Drake equation Fine-tuned universe Important publications in origin of life Panspermia Universal common ...

Photon

... is the formal reason why light is slower in media (such as glass) than in vacuum. (The reason for diffraction can be deduced from this by Huygens' principle .) Another way of phrasing it is to say that the photon, by being blended with the matter excitation to form a polariton, acquires an effective mass ...

Population genetics

... genetics. See also Ecological genetics Fitness landscape Founder effect Genotype-phenotype distinction Hardy-Weinberg principle Microevolution Molecular evolution Muller's ratchet Mutational meltdown Population bottleneck Selection Small ...

Protein

... albumin , which I have derived from [the Greek word] πρωτειοξ, because it appears to be the primitive or principle substance of animal nutrition." Investigation of proteins and their properties had been going on since about 1800 when scientists were ...

Signal transduction

... the gene. Upon activation by the hormone, they activate the transcription of the gene they were repressing. Signal amplification A principle of signal transduction is the signal amplification . The binding of one or a few neurotransmitter molecules can enable the entry of millions of ....

Thomas Malthus

... largely developed in reaction to the optimistic views of his father and his associates, notably Rousseau and William Godwin . In An Essay on the principle of Population , published in 1798 , Malthus predicted population would outrun food supply, leading to a decrease in food per person. This prediction ...

Vestibular system

... of eye movements from movements of the head is called vestibulo-ocular reflex , or short VOR . This reflex, combined with the push-pull principle described above, forms the physiological basis of the Rapid head impulse test or Halmagyi-Curthoys-test : when the function of your right balance ...

Virus

... less than 20 nanometers up to 400 nm and are composed of viral proteins arranged with icosahedral symmetry. Icosahedral architecture is the same principle employed by R. Buckminster-Fuller in his geodesic dome , and it is the most efficient way of creating an enclosed robust structure from multiple ...
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(Date:10/19/2014)... Improving household electricity access in India over the ... nation,s total carbon emissions growth during that time, ... journal Nature Climate Change ., "Energy access ... all aspects of life, including education, communication, and ... the study. , While increased energy access is ...
(Date:10/17/2014)... Rockville, MD – Accurate knowledge regarding Ebola is critical ... current risk of hazardous global outbreak and epidemic. The ... has launched a special issue, Ebola Virus and Public ... with necessary knowledge in this critical societal moment. ... Primer on Ebola for Clinicians . The primer was ...
(Date:10/16/2014)... Cancer constantly wages war on the human body. ... a stalemate. In pancreatic cancer, this stalemate—known as ... becoming aggressively malignant, a phenomena that is poorly ... in the laboratory of Salvatore Torquato, a Professor ... the conditions surrounding tumor dormancy and the switch ...
Breaking Biology News(10 mins):Improved electricity access has little impact on climate change 2Modeling tumor dormancy 2
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(Date:10/25/2014)... Oct. 24, 2014 (HealthDay News) -- Researchers who ... their findings are cause for concern. The ... are raised for human consumption contribute to the ... according to background information from the study. ... sicken about 2 million people and kill about ...
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Breaking Medicine News(10 mins):Health News:Studies Link Cold Sore Virus to Alzheimer's Risk 2Health News:Studies Link Cold Sore Virus to Alzheimer's Risk 3Health News:Researchers Say Antibiotics in Fish a Health Concern 2Health News:Osteoporosis Screening Guidelines May Miss Younger Women at Risk 2Health News:Dark Days Here for Folks With Seasonal Depression 2Health News:Brownsville Community Health Center Presents Fourth Annual ¡Vive Tu Vida! Get Up! Get Moving!® Event 2Health News:Brownsville Community Health Center Presents Fourth Annual ¡Vive Tu Vida! Get Up! Get Moving!® Event 3Health News:Brownsville Community Health Center Presents Fourth Annual ¡Vive Tu Vida! Get Up! Get Moving!® Event 4
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