Adaptive radiation
... radiation describes the rapid speciation of a
single or a few species to fill many ecological ... on the Galapagos islands developed from a
single species of finches that reached the islands. ... relatively short time, many species derive from a
single or a few ancestor species. From this large number ...
Biodiversity
... definitions
Biological diversity has no
single standard definition. One definition holds that ...
This is in fact the closest we come to a
single legally accepted definition of biodiversity, ...
From the viewpoint previously defined, no
single objective measure of biodiversity is possible, ...
Bacterium
... heterotrophy) can be combined differently in any
single microorganism, and even shifting between ... in many different ways. Bacteria can have a
single polar flagellum at one end of a cell, or they can ... stains
Firmicutes - bacteria with a
single membrane and thick peptidoglycan wall, giving ...
Cancer
... as thrombosis or hormonal changes.
Every
single item in the above list has a substantial ...
Types of cancer
Cancers originate within a
single cell. Hence, cancers can be classified by the ... of only the tumor, or the entire organ. Since a
single cancer cell can grow into a sizeable tumor, ...
Cloning
... clone in the biological sense, therefore, is a
single cell (like bacteria , lymphocytes etc.) or ... in horticulture to mean all descendants of a
single plant, produced by vegetative reproduction . ... of plants are clones, having been derived from a
single individual, multiplied by some process other than ...
Common descent
... all warm-blooded animals were descended from a
single "living filament":
... it be too bold ... therein vary between suggesting that there was a
single "first creature" to allowing that there may have ... with recent ideas about there having been a
single ancestral "genetic pool".
More recently, ...
Diabetes mellitus
... governments. In North America, it is the largest
single non-traumatic cause in adults of amputation, ... Scotland suggested diabetics were deficient in a
single chemical that was normally produced by the ... (most commonly of the kidneys ), and the
single word diabetes is applied to many of them. The ...
Electrophysiology
... possible to measure the current flowing through a
single ion channel and study its behavior. There are ...
Cell attached mode.
Advantages:
single channels can be recorded and channel properties ... Disadvantages: Impossible to record from
single channels.
4. Axon recording.
Advantages: ...
Bacterium
... heterotrophy) can be combined differently in any
single microorganism, and even shifting between ... in many different ways. Bacteria can have a
single polar flagellum at one end of a cell, or they can ... stains
Firmicutes - bacteria with a
single membrane and thick peptidoglycan wall, giving ...
Flagellum
... of flagella. Monotrichous bacteria have a
single flagellum. Lophotrichous bacteria have multiple ... which act in concert to drive the bacteria in a
single direction. Amphitrichous bacteria have a
single flagellum each on two opposite ends (only one ...
Gene
... it is very unlikely that variations within a
single gene—or
single genetic locus—fully determine one's genetic ... within a species' population. Variants of a
single gene are known as alleles , and differences in ...
Human
...
Monotheism generally believes that a
single deity , who is either the only one in existence, ... Whence are you? I know not. Do you feel yourself
single or multiple? I know not. Do you feel yourself ... the most generalized species on Earth , and few
single species occupy as many diverse environments as ...
Lipid
... are unbranched hydrocarbon chains, connected by
single bonds alone ( saturated fatty acids) or by both
single and double bonds ( unsaturated fatty ... critical micelle concentration the lipids form a
single layer on the liquid surface and are dispersed in ...
Microscope
... compound microscope would have a
single glass lens of short focal length for the objective, and another
single glass lens for the eyepiece or ocular. Modern ... actually very small simple instruments with a
single very strong lens. They were awkard in use but ...
Operator
... function might be called an operator.
A
single operator might conceivably qualify under all ... for example addition , say, is thought of as a
single operator able to act on numbers, vectors, ...
x 1 Q x 2 .
For operators on a
single argument, prefix notation such as −7 is ...
Polymerase chain reaction
... DNA when cells divide. It works by binding to a
single DNA strand and creating the complementary strand. ... The double-stranded DNA was separated into two
single strands by heating it to 96C. At this ... well-defined part of a DNA strand. This can be a
single gene, or just a part of a gene. As opposed to ...
Plasmid
... of copies of the same plasmid present in a
single cell .
Contents ... different types of plasmids to coexist in a
single cell, e.g., seven different plasmids have been ... , depending on their ability to coexist in a
single cell. These incompatibility groupings are due to ...
Protein
... be many different secondary motifs present in one
single protein molecule.
Tertiary structure : the overall shape of a
single protein molecule; the spatial relationship of the ... up to 3,000,000 (the muscle protein titin has a
single amino acid chain 27,000 subunits long). Such long ...
Species
... the concept of morphological species remains the
single most widely used species concept in everyday ... as separate species are now considered to be a
single taxon , and many formerly grouped populations ... over the years has failed to establish even a
single instance of two diagnostically different ...
Virus
... word virion or viron is used to refer to a
single infective viral particle.
The English plural ... acid genome , that may be either DNA or RNA ,
single or double stranded and positive or negative ... robust structure from multiple copies of a
single protein. The number of proteins required to form ...
Animal
... phyla, two are radially symmetric and have digestive chambers with a
single opening, which serves as both the mouth and the anus. These are the ... , and Mammalia . Since then the last four have all been subsumed into a
single phylum, the Chordata , whereas the various other forms have been ...
Antibody
... regions of the heavy and light chains can be fused together to form a
single chain variable fragment (scFv), which retains the original specificity of ... binding domain receptors it can express on its surface.
The antibodies a
single B lymphocyte produces can differ in their heavy chain and the B cell often ...
Artificial life
... try instead to mimic life processes to understand the appearance of
single phenomena. The usual way is through an agent based model , which usually ... to execute cellular automata, eventually reducing it to the size of a
single circuit board. This "cellular automata machine" allowed an explosion of ...
Biophysics
... things like solving a protein structure or measuring the kinetics of
single molecule interactions, biophysics is also understood to encompass ... in some biology department somewhere. To include some: gene regulation ,
single protein dynamics, bioenergetics, patch clamping , biomechanics .
...
Chromatin
... proteins.
Figure 2: Different levels of DNA condensation. (1)
single DNA strand. (2) Chromatin strand ( DNA with histones ). (3) ... proteins.
Figure 2: Different levels of DNA condensation. (1)
single DNA strand. (2) Chromatin strand (DNA with histones). (3) Condensed ...
Genetic code
... is composed of tri-nucleotide units called codons , each coding for a
single amino acid. Each nucleotide sub-unit consists of a phosphate , ... inosine and the U-G basepair.
Only two amino acids are specified by a
single codon; one of these is the amino-acid methionine , specified by the codon ...
Computed axial tomography
... from a large series of two-dimensional X-ray images taken around a
single axis of rotation. The word " tomography " is derived from the Greek ... systems can complete a scan of the chest in less time than it takes for a
single breath (useful if the patient cannot hold his/her breath) and display the ...
DNA
... trivial chemical reactions, and recreating the "other half" of each new
single strand by drowning each half in a "soup" made of the four bases. Since ... of heredity", pieces of DNA as people typically think of them are not
single molecules. Rather, they are pairs of molecules, which entwine like vines ...
Enzyme
...
Enzymes are essential to living organisms, and a malfunction of even a
single enzyme out of approximately 2,000 types present in our bodies can lead to ... EC 5 Isomerases : catalyze isomerization changes within a
single molecule
EC 6 Ligases : join two molecules with covalent bonds
...
Eugenics
... heights. By the 1930s, however, these had been reconciled into a
single model by the work of Ronald Fisher , who developed more powerful ... of children, and even encouraged a service in which "racially pure"
single women would become impregnated by SS officers ( Lebensborn ). Many of ...
Genetic code
... is composed of tri-nucleotide units called codons , each coding for a
single amino acid. Each nucleotide sub-unit consists of a phosphate , ... inosine and the U-G basepair.
Only two amino acids are specified by a
single codon; one of these is the amino-acid methionine , specified by the codon ...
Hardy-Weinberg principle
... after one generation of random mating , the genotype frequencies at a
single gene locus will become fixed at a particular equilibrium value. It also ... of the allele frequencies at that locus.
In the simplest case of a
single locus with two alleles A and a with allele frequencies of p and q , ...
Homeobox
... homeodomain binds DNA in a specific manner. However, the specificity of a
single homeodomain protein is usually not enough to recognize only its desired ... proteins. Such complexes have a much higher target specificity than a
single homeodomain protein.
A particular subgroup of homeobox genes are the ...
Major histocompatibility complex
... cell of the body. Class I molecules are heterodimers , consisting of a
single transmembrane polypeptide chain (the α-chain) and a β 2 ... a broad term which identifies any kind of natural selection in which no
single allele is absolutely most fit. Frequency dependent selection and ...
Animal
... phyla, two are radially symmetric and have digestive chambers with a
single opening, which serves as both the mouth and the anus. These are the ... , and Mammalia . Since then the last four have all been subsumed into a
single phylum, the Chordata , whereas the various other forms have been ...
Monoclonal antibody
... because they were produced by one type of immune cell , all clones of a
single parent cell. Given any substance, it is possible to create monoclonal ... bind to many epitopes of a given antigen, while monoclonals bind to a
single epitope. In the processing of antibodies, certain binding capabilities ...
Peptide
... bond . An amide bond is somewhat shorter than a typical carbon-nitrogen
single bond, and has a partial double-bond character, because the participating ... different properties.
Notes on terminology
A polypeptide is a
single linear chain of amino acids.
A protein is one or more polypeptides ...
Peptide
... bond . An amide bond is somewhat shorter than a typical carbon-nitrogen
single bond, and has a partial double-bond character, because the participating ... different properties.
Notes on terminology
A polypeptide is a
single linear chain of amino acids.
A protein is one or more polypeptides ...
Ribosome
... in eukaryotic cells. Several free ribosomes can associate on a
single mRNA molecule to form a polyribosome or polysome . Free ribosomes ... 3' end of the mRNA. Usually, several ribosomes are working parallel on a
single mRNA.
See also: protein assembly
...
Secondary structure
... is frequently used to describe the protein secondary structures with a
single letter code. DSSP is an acronym for "Dictionary of Protein Secondary ... of polypeptide chains with favored orientations of the polypeptide around
single bonds: Two pleated sheets. Proc. Natl. Acad. Sci. USA, 37:729-740 (1951). ...