NationMaster - Encyclopedia: Biological trait

In biology, a trait or character is a feature of an organism. The term phenotype is sometimes used as a synonym for trait in common use, but strictly speaking, does not indicate the trait, but the state of that trait (e.g., the trait eye colour has the phenotypes blue, brown and hazel). Biology (from Greek Î²Î¯Î¿Ï‚ Î»ÏŒÎ³Î¿Ï‚, see below) is the branch of science dealing with the study of living organisms. ... A crab is an example of an organism. ... Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ... Look up Synonym in Wiktionary, the free dictionary. ... This article is about the geographical distribution and social connotations of eye color in humans. ...

Definition

A trait may be any single feature or quantifiable measurement of an organism. However, the most useful traits for genetic analysis are present in different forms in different individuals. Genetic testing allows the genetic diagnosis of vulnerabilities to inherited diseases, and can also be used to determine a persons ancestry. ...

A visible trait is the final product of many molecular and biochemical processes. In most cases, information starts with DNA traveling to RNA and finally to protein (ultimately affecting organism structure and function). This is the Central Dogma of molecular biology as stated by Francis Crick. Molecular biology is the study of biology at a molecular level. ... Biochemistry is the study of the chemical processes and transformations in living organisms. ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... Ribonucleic acid (RNA) is a nucleic acid polymer consisting of nucleotide monomers. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... The central dogma of molecular biology (sometimes Cricks central dogma after Francis Crick who coined the term and discovered some of the principles) states that the flow of genetic information is DNA to RNA to protein. With a few notable exceptions, all biological cells conform to this rule. ... Molecular biology is the study of biology at a molecular level. ... Francis Harry Compton Crick OM (8 June 1916 â€“ 28 July 2004) was an English physicist, molecular biologist and neuroscientist, most noted for being one of the co-discoverers of the structure of the DNA molecule in 1953. ...

This information flow may also be followed through the cell as it travels from the DNA in the nucleus, to the Cytoplasm, to the Ribosomes and the Endoplasmic Reticulum, and finally to the Golgi Apparatus, which may package the final products for export outside the cell. Drawing of the structure of cork as it appeared under the microscope to Robert Hook from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... The eukaryotic cell nucleus. ... Organelles. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... The endoplasmic reticulum (endoplasmic meaning within the cytoplasm, reticulum meaning little net in Latin) or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport (e. ... Diagram of the endomembrane system in a typical eukaryote cell Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ...

Cell products are released into the tissue, and organs of an organism, to finally affect the physiology in a way that produces a trait. Biological tissue is a collection of interconnected cells that perform a similar function within an organism. ... In biology, an organ (Latin: organum, instrument, tool) is a group of tissues that perform a specific function or group of functions. ... A crab is an example of an organism. ... Physiology (in Greek physis = nature and logos = word) is the study of the mechanical, physical, and biochemical functions of living organisms. ...

Environmental origin

The environment plays a large role in the determination of traits. This is natural as all organisms must have input (and output) of energy and matter in order to maintain their overall elevated energy state. An energy level is a quantified stable energy, which a physical system can have; the term is most commonly used in reference to the electron configuration of electrons, in atoms or molecules. ...

Genetic origin of traits in diploid organisms

The heritable unit that may produce a trait is called a gene. A gene is a strand of DNA that is part of a very long and compacted string of DNA called a chromosome. An important reference point along this string is the centromere; the distance from a gene to the centromere is referred to as the gene's locus or map location. A chromosomal region known to control a trait while the responsible gene within not being identified is referred to as a quantitative trait locus. This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... In biology, histones are the chief proteins of chromatin. ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... Figure 1: Chromosome. ... The centromere is a region of chromosomes with a special sequence and structure. ... In biology and evolutionary computation, a locus is a fixed position on a chromosome, such as the position of a gene. ... Quantitative trait locus (QTL) is a region of DNA that is associated with a particular trait (e. ...

The nucleus of a diploid cell contains two of each chromosome, with homologous (mostly identical) pairs of chromosomes having the same genes at the same loci. In biology, two or more structures are said to be homologous if they are alike because of shared ancestry. ... The word locus (plural loci) is Latin for place: In biology and evolutionary computation, a locus is the position of a gene (or other significant sequence) on a chromosome. ...

Mendelian expression of genes in diploid organisms

A gene is only a DNA code sequence; the slightly different variations of that sequence are called alleles. Alleles can be significantly different and produce different product RNAs. RNA codons. ... In genetics, an allele (pronounced al-eel) is any one of a number of viable DNA codings occupying a given locus (position) on a chromosome. ... Ribonucleic acid (RNA) is a nucleic acid polymer consisting of nucleotide monomers. ...

Combinations of different alleles thus go on to generate different traits through the information flow charted above. For example, if the alleles on homologous chromosomes exhibit a "simple dominance" relationship, the trait of the "dominant" allele shows in the phenotype. An allele is any one of a number of alternative forms of the same gene occupying a given locus (position) on a chromosome. ... The central dogma of molecular biology (sometimes Cricks central dogma after Francis Crick who coined the term and discovered some of the principles) states that the flow of genetic information is DNA to RNA to protein. With a few notable exceptions, all biological cells conform to this rule. ... Figure 1: Chromosome. ... Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ...

Gregor Mendel pioneered modern genetics. His most famous analyses were based on clear-cut traits with simple dominance. He determined that the heritable units, he called "genes", occurred in pairs and could exhibit linkage. His tool was statistics: long before the molecular model of DNA was introduced by James D. Watson and Francis Crick. Gregor Johann Mendel (July 20[1], 1822 â€“ January 6, 1884) was an Augustinian abbot who is often called the father of modern genetics for his study of the inheritance of traits in pea plants. ... Inheritance is the practice of passing on property, titles, debts, and obligations upon the death of an individual. ... This stylistic schematic diagram shows a gene in relation to the double helix structure of DNA and to a chromosome (right). ... Genetic linkage occurs when particular alleles are inherited jointly. ... A graph of a bell curve in a normal distribution showing statistics used in educational assessment, comparing various grading methods. ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ... James Dewey Watson KBE(Hon) ForMemRS (born April 6, 1928) is an American scientist, best known as one of the four discoverers of the structure of the DNA molecule. ... Francis Harry Compton Crick OM (8 June 1916 â€“ 28 July 2004) was an English physicist, molecular biologist and neuroscientist, most noted for being one of the co-discoverers of the structure of the DNA molecule in 1953. ...

Biochemistry of dominance and extensions to expression of traits

The biochemistry of the intermediate proteins determines how they interact in the cell. Therefore, biochemistry predicts how combinations of different alleles will produce varying traits. Biochemistry is the study of the chemical processes and transformations in living organisms. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Philosophy of science is the branch of philosophy that studies the philosophical assumptions, foundations, and implications of science, including the formal sciences, natural sciences, and social sciences. ...

Extended expression patterns seen in diploid organisms include facets of incomplete dominance, codominance, and multiple alleles. It has been suggested that this article or section be merged with dominance relationship. ... It has been suggested that this article or section be merged with incomplete dominance. ... An allele is any one of a number of viable DNA codings of the same gene (sometimes the term refers to a non-gene sequence) occupying a given locus (position) on a chromosome. ...

See also

Category: Classical genetics Genetics (from the Greek genno Î³ÎµÎ½Î½ÏŽ= give birth) is the science of genes, heredity, and the variation of organisms. ... A skill is an ability, usually learned, to perform actions. ... Genetic linkage occurs when particular alleles are inherited jointly. ... Morphogenesis is also the name of a band. ... Individuals in the mollusk species Donax variabilis show diverse coloration and patterning in their phenotypes. ... The genotype-phenotype distinction refers to the fact that while genotype and phenotype of an organism are related, they do not necessarily coincide. ... In ecology and biology, a norm of reaction describes the pattern of phenotypic expression of a single genotype across a range of environments. ... In biology and psychology Gene-environment interaction is a term used to describe any phenotypic effects that are due to interactions between the environment and genes. ... Heritability, as used professionally in genetics, has a very precise definition. ... Quantitative genetics is the study of continuous traits (such as height or weight) and its underlying mechanisms. ... Genetic architecture refers to the underlying genetic basis of a phenotypic trait. ... It has been suggested that dominant gene be merged into this article or section. ... Epistasis takes place when the action of one gene is modified by one or more others that assort somewhat independently. ... Polygenic inheritance is the inheritance pattern of a trait controlled by two or more genes. ... Pleiotropy is the multiple effects of a single gene. ... We dont have an article called Phenotypic plasticity Start this article Search for Phenotypic plasticity in. ... Norms of reaction for two genotypes. ... In evolutionary biology, fitness landscapes or adaptive landscapes are used to visualize the relationship between genotypes (or phenotypes) and replicatory success. ... It has been suggested that this article or section be merged with Epigenetics. ... Epigenetics is the study of reversible heritable changes in gene function that occur without a change in the sequence of nuclear DNA. It is also the study of the processes involved in the unfolding development of an organism. ... A maternal effect, in genetics, is the phenomena where the genotype of a mother is expressed in the phenotype of its offspring. ... Dual inheritance theory, (or DIT), in sharp contrast to the notion that culture overrides biology, posits that humans are products of the interaction between biological evolution and cultural evolution. ... Segmentation in biology refers to the division of some metazoan bodies and plant body plans into a series of semi-repetitive segments, and the question of the benefits and costs of doing so. ... Many organisms consist of modules, both anatomically and in their metabolism. ... Evolvability is a concept in that relates ability of a particular phenotype to be robust to mutations. ... Mutational robustness describes the extent to which an organisms phenotype remains constant in spite of mutation. ... The evolution of sex is a major puzzle in modern evolutionary biology. ... Conrad Hal Waddington (1905 â€” 1975), known to his friends as Wad, was a developmental biologist, paleontologist, geneticist, embryologist and philosopher. ... Richard Lewontin Richard Charles Dick Lewontin (born March 29, 1929) is an American evolutionary biologist, geneticist and social commentator. ... Nature versus nurture is a shorthand expression for debates about the relative importance of an individuals innate qualities (nature) versus personal experiences (nurture) in determining or causing individual differences in physical and behavioral traits. ... This is a list of topics in evolutionary biology and evolution. ...

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