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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 ...
Other Contents
(Date:4/18/2014)... while feeding a world population predicted to reach ... approach to conservation that considers human-altered landscapes such ... and the natural habitat that supports it might ... where at least three-quarters of the land surface ... is vulnerable to human-caused impacts such as climate ...
(Date:4/18/2014)... [Brown University] Asteroid and comet impacts can cause ... regional or even global scales. But new research from ... signatures of ancient life at the time of an ... Pete Schultz has found fragments of leaves and preserved ... ancient impacts in Argentina. The material could provide a ...
(Date:4/17/2014)... RSV infection , Respiratory syncytial virus (RSV) ... infections, generating life-threating illness in very young and ... limited. RSV enters host cells through the fusion ... bundle. Small interfering peptides that prevent bundle formation ... are highly susceptible to degradation. In this issue ...
Breaking Biology News(10 mins):Stanford researchers rethink 'natural' habitat for wildlife 2Stanford researchers rethink 'natural' habitat for wildlife 3Stanford researchers rethink 'natural' habitat for wildlife 4Impact glass stores biodata for millions of years 2Impact glass stores biodata for millions of years 3JCI online ahead of print table of contents for April 17, 2014 2JCI online ahead of print table of contents for April 17, 2014 3JCI online ahead of print table of contents for April 17, 2014 4JCI online ahead of print table of contents for April 17, 2014 5JCI online ahead of print table of contents for April 17, 2014 6
(Date:4/18/2014)... 2014) -- A group of scientists from the ... Sanders-Brown Center on Aging has found interesting new ... function in Parkinson,s disease (PD). , Published ... study, which assessed cognitive function in depressed and ... replacement therapy commonly used to treat motor symptoms ...
(Date:4/18/2014)... memories? How did it make you feel? According to ... experience, such as how sad you were or how ... when you can,t stop thinking about it. , ... context of the memories, rather than how you felt, ... the negative effects of these memories, a new study ...
(Date:4/18/2014)... scientists could lead to potential new treatments for breaking ... , Fibrosis, or scarring, is a hallmark of ... lungs can lead to serious organ damage and, in ... options centers on findings made by Swati Bhattacharyya, PhD, ... that a specific protein plays in promoting fibrosis. ...
(Date:4/17/2014)... CHAMPAIGN, Ill. One of the most popular vaccine ... choice. And doctors may be overlooking some cost factors ... actually a more expensive option, according to a new ... of vaccines to administer can be driven by numerous ... study and a professor of computer science and of ...
(Date:4/17/2014)... MANHASSET, NY In a review published in the ... MD, president of The Feinstein Institute for Medical Research, ... the medical community,s approach to treating sepsis, ... 200,000 Americans. , Sepsis occurs when molecules released into ... inflammation throughout the body. Inflammation is necessary for maintaining ...
Breaking Medicine News(10 mins):Health News:Treating depression in PD patients: New research 2Health News:New study suggests a better way to deal with bad memories 2Health News:New study suggests a better way to deal with bad memories 3Health News:New clues on tissue scarring in scleroderma 2Health News:Study recalculates costs of combination vaccines 2Health News:Feinstein Institute researcher publishes new perspective on sepsis 2
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