A frame or framework is a structural system or a skeleton that supports other components of the object. It is used in this basic sense in art, construction, and mechanical engineering, and the expression 'frame' for eyeglasses.
The word also has many extended, metaphorical meanings in various fields:
The Frames is also the name of an Irish rock band, fronted by Glen Hansard.
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A frame or framework is a structural system or a skeleton that supports other components of the object. The definition is: "that which segregates and recombines with appreciable frequency." According to this definition, even an asexual genome could be considered a gene, insofar it have an appreciable permanency through many generations. one complete game of snooker; a match usually comprises at least three frames. Also, he proposed an evolutionary concept of gene to be used when we are talking about natural selection favoring some gene. in psychology, Framing (psychology). Williams first explicitly advocated the gene-centric view of evolution in his book Adaptation and Natural Selection. in law, to frame someone is to make it look as if they committed a crime when they in fact did not commit said crime, as in the title of the movie Who Framed Roger Rabbit; see frameup. George C.
See frame (dance). This dogma has since been shown to have exceptions, such as reverse transcription in retroviruses. the connection between lead and follow in partner dancing. Together, these discoveries established the central dogma of molecular biology, which states that proteins are translated from RNA which is transcribed from DNA. each player's turn in bowling games. Watson and Francis Crick demonstrated the molecular structure of DNA. also in mathematics, a frame can refer to a complete Heyting algebra. In 1953, James D.
Also projective frame. Oswald Avery, Collin Macleod, and Maclyn McCarty showed in 1944 that DNA holds the gene's information. See vierbein for an orthonormal frame. This showed that specific genes code for specific proteins, leading to the "one gene, one enzyme" hypothesis. in mathematics, a frame is an abstract concept on a manifold, generalising frame of reference to a basis for the tangent bundle varying from point to point. In 1941, George Wells Beadle and Edward Lawrie Tatum showed that mutations in genes caused errors in certain steps in metabolic pathways. a frame of reference in physics. In what is now known as Griffith's experiment, injections into a mouse of a deadly strain of bacteria that had been heat-killed transferred genetic information to a safe strain of the same bacteria, killing the mouse.
a narrative frame in literature, film, or storytelling. In 1928, Frederick Griffith showed that genes could be transferred. a frame tale in literature. With this knowledge, Morgan and his students began the first chromosomal map of the fruit fly Drosophila. Semantic frames in cognitive science, linguistics, or communication theory. He later showed that genes occupy specific locations on the chromosome. the frame problem in artificial intelligence, a data structure for representing a stereotyped situation. In 1910, Thomas Hunt Morgan showed that genes reside on specific chromosomes.
in video compression different frames –- called I-frames, P-frames, B-frames, and D-frames –- are used for motion compensation. The existence of genes was first suggested by Gregor Mendel, who, in the 1860s, studied inheritance in pea plants and hypothesized a factor that conveys traits from parent to offspring. a complete image, or the set of all picture elements representing it, in video display. Yet, though the alleles of a gene differ in sequence, nevertheless they are regarded as a single gene (occupying a single locus). one of the film frames or video frames composing a film or video
an A-frame, often used as a caning -, whipping - or flogging frame, used for securing the victim of physical punishment (either standing with his hands tied where the side bars meet above him, or to bend over the shorter cross-bar). Though the two sequences may remain the same, or be only slightly altered, they are typically regarded as separate genes (i.e. frames are often called after a shape they resemble, e.g. Errors during DNA replication may lead to the duplication of a gene, which may diverge over time. in mechanical engineering, a bicycle frame, for instance. Typically, he or she will simply attribute it to variations within a gene. a beehive frame. Indeed, a breeder 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.
a space frame in construction. Thus, though regulatory elements are often distinguished from genes in molecular biology, in effect they satisfy the shared and historical sense of the word. in art, a picture frame is a solid border around a picture or painting. The influence of such variations on the trajectory of evolution through natural selection may be as large as or larger than variation in sequences that encode proteins. For example, natural variations within regulatory sequences appear to underlie many of the heritable characteristics seen in organisms. Just as there are many factors influencing the expression of a particular DNA strand, there are many ways to have genetic mutations.
The latter meaning of gene is the result of more "material entity" than the first one. This complex process helps explain the different meanings of "gene":. The same DNA strand in two different individuals may result in different traits because of the effect of other DNA strands or the environment. For various reasons, the relationship between DNA strand and a phenotype trait is not direct.
The ways that gene copies interact are explained by chemical dominance relationships (more at genetics, allele). With respect to each gene, the copies that an individual possesses are liable to be distinct alleles, which may act synergistically or antagonistically to generate a trait or phenotype. In such organisms, the copies are practically never identical. These organisms are called diploid if they have two copies or polyploid if they have more than two copies.
Many species carry more than one copy of their genome within each of their somatic cells. As an example of the former, many of the genes involved in spermatogenesis reside together on the Y chromosome. Two genes positioned near one another on a chromosome may encode proteins that figure in the same cellular process or in completely unrelated processes. Genes that appear together on the chromosomes of one species, such as humans, may appear on separate chromosomes in another species, such as mice.
The location (or locus) of a gene and the chromosome on which it is situated is in a sense arbitrary. All the genes and intervening DNA together make up the genome of an organism, which in many species is divided among several chromosomes and typically present in two or more copies. In the primary molecular sense, they represent parts of a gene, however. Introns are removed on the heels of transcription by splicing.
Moreover, the genes are often fragmented internally by non-coding sequences called introns, which can be many times longer than the coding sequence. In most eukaryotic species, very little of the DNA in the genome encodes proteins, and the genes may be separated by vast sequences of so-called junk DNA. The sequence of codons in a gene specifies the amino-acid sequence of the protein it encodes. A sequence of three consecutive nucleotides, called a codon, is the protein-coding vocabulary.
These four nucleotides constitute the genetic alphabet. Four kinds of sequentially linked nucleotides compose a DNA molecule or strand (more at DNA). (In early genetics, genes could be identified only if there were mutations, or alleles.) Nonetheless, estimates are made based on current knowledge. Estimates of the number of genes in an organism are somewhat controversial because they depend on the discovery of genes, and no techniques currently exist to prove that a DNA sequence contains no gene.
The shown table gives typical numbers of genes and genome size for some organisms. In preference each symbol maintains parallel construction in different members of a gene family and can be used in other species, especially the mouse. This also facilitates electronic data retrieval from publications. It is necessary to provide a unique symbol for each gene so that people can talk about them.
Each symbol is unique and each gene is only given one approved gene symbol. All approved symbols are stored in the HGNC Database. For each known human gene the HUGO Gene Nomenclature Committee (HGNC) approve a gene name and symbol (short-form abbreviation). On the other hand, RNA retroviruses, such as AIDS, require the reverse transcription of their genome from RNA into DNA before their proteins can be synthesized.
Because they use RNA, their cellular hosts may synthesize their proteins as soon as they are infected and without the delay in waiting for transcription. Most living organisms carry their genes and transmit them to offspring as DNA, but some viruses carry only RNA. The DNA sequences from which such RNAs are transcribed are known as non-coding RNA, or RNA genes. For example, RNAs known as ribozymes are capable of enzymatic function, and small interfering RNAs have a regulatory role.
However, for some gene sequences, the RNA molecules are the actual functional products. In most cases, RNA is an intermediate product in the process of manufacturing proteins from genes. A gene's most common allele is called the wild type allele, and rare alleles are called mutants. Variants of a single gene are known as alleles, and differences in alleles may give rise to differences in traits, for example eye colour.
Once propagated to the next generation, this mutation may lead to variations within a species' population. in DNA replication) mutations in the sequence of a gene may arise. Due to rare, spontaneous errors (e.g. According to Dawkins, the possibly disappointing answer to the question "what is the meaning of life?" may be "the survival and perpetuation of ribonucleic acids and their associated proteins".
A human that behaved in such a way would be described as "selfish," although ironically a selfish gene may promote altruistic behaviours. He points out in his book, The Selfish Gene, that to be successful genes need have no other "purpose" than to propagate themselves, even at the expense of their host organism's welfare. This is the basis of the selfish gene view, popularized by Richard Dawkins. Indeed, if the sacrifice of one individual enhances the survivability of other individuals with the same gene, the death of an individual may enhance the overall survival of the gene.
Often, many individual organisms share a gene; thus, the death of an individual need not mean the extinction of the gene. The genes that exist today are those that have reproduced successfully in the past. The instrumental roles of their protein products range from mechanical support of the cell structure to the transportation and manufacture of other molecules and to the regulation of other proteins' activities. In multicellular organisms they control the development of the individual from the fertilized egg and the day-to-day functions of the cells that make up tissues and organs.
Through the proteins they encode, genes govern the cells in which they reside. The genetic code is essentially the same for all known life, from bacteria to humans. The genetic code determines how the coding DNA sequence is converted in to a protein sequence (transcription and translation). In molecular biology, a gene is considered to be the region of DNA (or RNA, in the case of some viruses) that determines the structure of a protein (the coding sequence), together with the region of DNA that controls when and where the protein will be produced (the regulatory sequence).
. The term phenotype refers to the characteristics that result from this interplay (see genotype-phenotype distinction). These aspects of inheritance—the interplay between genes and environment, the influence of many genes—appear to be the norm with regard to many and perhaps most ("complex" or "multi-factoral") traits. Moreover, it is very unlikely that variations within a single gene—or single genetic locus—fully determine one's genetic predisposition for obesity.
This is because biologists know that many factors other than genes decide whether a person is obese or not: eating habits, exercise, prenatal environment, upbringing, culture and the availability of food, for example. In common speech, "gene" is often used to refer to the hereditary cause of a trait, disease or condition—as in "the gene for obesity." Speaking more precisely, a biologist might refer to an allele or a mutation that has been implicated in or is associated with obesity. The Sequence Ontology project defines a gene as: "A locatable region of genomic sequence, corresponding to a unit of inheritance, which is associated with regulatory regions, transcribed regions and/or other functional sequence regions". Following the discovery that DNA is the genetic material, and with the growth of biotechnology and the project to sequence the human genome, the common usage of the word "gene" has increasingly reflected its meaning in molecular biology, namely the segments of DNA which cells transcribe into RNA and translate, at least in part, into proteins.
It may refer to either material or conceptual entities. Because each discipline models the biology of life differently, the usage of the word gene varies between disciplines. The word "gene" (coined 1909 by Danish botanist Wilhelm Johannsen) comes from the Greek genos ("origin") and is shared by many disciplines, including classical genetics, molecular genetics, evolutionary biology and population genetics. Genes encode the information necessary to construct the chemicals (proteins etc.) needed for the organism to function.
via transfection, or on viruses). Genetic material can also be passed between un-related individuals (e.g. During reproduction, the genetic material is passed on from the parent(s) to the offspring. They are encoded in the organism's genetic material (usually DNA or RNA), and control the development and behavior of the organism.
Genes are the units of heredity in living organisms. without the introns. or the transcribed RNA after splicing, i.e. or the transcribed RNA, prior to splicing;.
a nucleotide sequence in a DNA strand;. This interaction finally produces the trait. Once produced, the protein interacts with the many other proteins in the cell, according to the cell metabolism. The translation of RNA into a protein also starts with a specific start and stop sequence.
Prokaryotes produce a similar effect by shifting reading frames during translation. Because of the complexity of the splicing process, one transcribed RNA may be spliced in alternate ways to produce not one but a variety of proteins (alternative splicing) from one pre-mRNA. Therefore, the DNA strand needs to be in an exon to be expressed. Eukaryotic cells splice the transcripts of a gene, by keeping the exons and removing the introns.
The RNA is often edited before its translation into a protein. This is a permanent form of regulation of the transcription. The DNA strand may also be silenced through DNA methylation or by chemical changes to the protein components of chromosomes (see histone). Therefore, to be expressed, our DNA strand needs to be properly regulated by other DNA strands.
Over the short term, this regulation occurs through the binding or unbinding of proteins, known as transcription factors, to specific non-coding DNA sequences called regulatory elements. Cells regulate the activity of genes in part by increasing or decreasing their rate of transcription. If not, it is considered as junk DNA, and is not expressed. Because the transcription starts from a specific base-pair sequence (a promoter) and stops at another (a terminator), our DNA strand needs to be correctly placed between the two.
The DNA strand is expressed into a trait only if it is transcribed to RNA.