pattern

X-ray crystallography

... is a technique in crystallography in which the pattern produced by the diffraction of x-rays through ...seful information in diffraction experiments. The pattern of diffraction peaks can be used to quickly identify materials (thanks to the JCPDS pattern databa...

Secondary structure

...ng pattern. If the helix or sheet hydrogen bonding pattern is too short they are designated as T or B, respectively. Other protein secondary structure assignment categories exist (sharp turns, Omega loops etc.), but they are less frequently used. RNA RNA secondary structure is generally divided into heli...

Prion

...ed a genetic trait (termed [PSI+]) with an unusual pattern of inheritance . Despite many years of effort, Cox could not identify a conventional mutation that was responsible for the [PSI+] trait. In 1994 , yeast geneticist Reed Wickner correctly hypothesized that [PSI+] as well as another mysterious herit...

Polymerase chain reaction

...s would be run out on an agarose gel, and the band pattern will tell you if the individual is homozygous T, homozygous C, or heterzygous T/C. This methodology has several applications, such as amplifying certain haplotypes (when certain alleles at 2 or more SNPs occur together on the same chromosome [Linkag...

Parallel evolution

...f sharks and ichthyosaurs ). A similar banding pattern that is found in almost all species of moths is another example of parallel evolution. Related articles Convergent evolution Evolutionary relay Mimicry...

Morphogenesis

...of asymmetries within the oocyte and proceeds to pattern formation along the embryonic axes. The developmen...s at the edge of each parasegment. This expression pattern is initiated by the pair-rule genes (like even-skipped ) that code for transcription factors that r...

Molecular phylogeny

...les of organisms distantly related usually show a pattern of dissimilarity. Molecular phylogeny uses such data to build a "relationship tree" that shows the probable evolution of various organisms. Not until recent decades, however, has it been possible to isolate and identify these molecular structures. ...

Mendelian inheritance

...and that they somehow blended together to form the pattern for the offspring. This theory accounted for the fact that offspring tended to resemble their parents without all members of a population eventually averaging themselves out. Mendel proposed instead a theory of particulate inheritance, in which char...

Mathematical biology

...emical theory of morphogenesis [9] Biological pattern formation [10] Modelling the movement of interacting cell populations [11] Mathematical modelling of scar tissue formation [12] These examples are characterised by complex , nonlinear mechanisms and it is being increasingly recognised th...

Leaf

...yer of the mesophyll. They are typical examples of pattern formation through ramification. The veins are made up of: xylem , which brings water from the stem into the leaf. phloem , which usually moves sap out, the latter containing the glucose produced by photosynthesis in the leaf. The xylem typi...

Isozyme

...ng, but instead modify either its function, or its pattern of gene expression , then the two variants may both be favoured by natural selection and become specialised to different functions. For example, they may be expressed at different stages of development or in different tissues. Allozymes may resul...

Intron

... of an intron, and therefore that a similar intron pattern may arise in two different species by a form of convergent evolution . See also selfish DNA noncoding DNA intein Reference Walter Gilbert (1978 Feb 9) "Why Genes In Pieces?" Nature 271 (5645):501....

Hormone

...cells; the action of hormones is determined by the pattern of secretion and the signal transduction of the receiving tissue. Hormone actions vary widely, but can include stimulation or inhibition of growth, induction or suppression of apoptosis (programmed cell death), activation or inhibition of the i...

Growth curve

...an 8 hour cell growth experiment . The observed pattern of bacterial growth is bi-phasic because two different sugars were present, glucose and lactose. The bacteria prefer to consume glucose (Phase I) and only use the lactose (Phase II) after the glucose has been depleted. Analysis of the molecular basis...

Genomics

...ical discoveries. If a particular DNA sequence or pattern is present among many members of a clade , that sequence is said to have been conserved among the species. Evolutionary conservation of a DNA sequence may imply that it confers a relative selective advantage to the organisms that possess it. Cons...

Genetic fingerprinting

...t has also been used to generate hypotheses on the pattern of the human diaspora in prehistoric times. T...rn. This film is then developed to make a visible pattern of bands called DNA fingerprinting. Recently, an additional technique for genetic fingerprinting ha...

Gene

...reeder or geneticist, in following the inheritance pattern of a trait, has no immediate way to know whether this pattern arises from coding sequences or regulatory sequences. Typically, he or she will simply attribute it ...

Francis Galton

...that was to last until 1917 ), identifying common pattern in fingerprints and devising a classification system that survives to this day. He also estimated the probability of two persons having the same fingerprint and studied the heritability and racial differences in fingerprints. Galton invented the Qu...

Endosymbiont

...stribution of symbionts is related to the observed pattern of coral bleaching and recovery. Thus the distribution of Symbiodinium on coral reefs and its role in coral bleaching presents one of the most complex and interesting current problems in reef ecology. Bacterial obligate endosymbionts in inse...

Endosymbiont

...stribution of symbionts is related to the observed pattern of coral bleaching and recovery. Thus the distribution of Symbiodinium on coral reefs and its role in coral bleaching presents one of the most complex and interesting current problems in reef ecology. Bacterial obligate endosymbionts in inse...

Morphogenesis

...of asymmetries within the oocyte and proceeds to pattern formation along the embryonic axes. The developmen...s at the edge of each parasegment. This expression pattern is initiated by the pair-rule genes (like even-skipped ) that code for transcription factors that r...

DNA

...sure its exact value of 2 nanometres from an X-ray pattern obtained by Franklin. The same pattern also gave them the 3.4 nanometre-per-10 bp " pitch " of the helix. The pair quickly converged upon a...

Dialysis

...up plumbing on the machine in a moderately complex pattern that has been worked out to move blood through the filter, allow for saline drip (or not), allow for various other medications/chemicals to be administered. How the plumbing is setup may vary between models of machine and they types of filters. For...

Diabetes mellitus

...ng (MODY). There is an even stronger inheritance pattern for Type 2 diabetes; those with type 2 ancestors or relatives have very much higher chances of developing Type 2. It is also often connected to obesity, which is found in approximately 85% of (North American) patients diagnosed with that form of the ...

Collagen

...agen sub-units. The sequence generally follows the pattern Gly-X-Y, where X is proline, and Y is proline or hydroxyproline. There are very few other proteins with such regularity. The inordinate number of Gly residues allows the otherwise sterically disallowed, tight coiling of each of the alpha chain subuni...

Cancer

... , or has double ones. Also, the DNA methylation pattern of the cell changes, activating and deactivating genes more or less at random. Cells that divide at a high rate, such as epithelials , show a higher risk of becoming tumor cells than those which divide less, for example neurons . In cellular m...

Barr body

...other will. This is what results in the coloration pattern of female calico cats ; pigmentation genes on the X chromosome are activated in different patches of skin based on which chromosome is condensed in those regions. The Barr body chromosome is generally considered to be inert, but in fact a small num...

Avian influenza

...etween 1999 and 2002. They found "a clear temporal pattern of progressively increasing pathogenicity". [1] Symptoms In humans, it has been found that avian flu causes similar symptoms to other types of flu: fever cough sore throat muscle aches conjunctivitis in severe cases of avia...