Facts about Gene
The location (or locus) of a gene and the chromosome on which it is situated is, in a sense, arbitrary.
The word pangenesis is made from the Greek words pan (a prefix meaning "whole," "encompassing") and genesis ("birth") or genos ("origin").
Genetic material can also be passed between unrelated individuals on viruses or through the process of transfection used in genetic engineering.
The sequence of codons in a gene specifies the amino acid sequence of the protein it encodes.
The term "gene" is shared by many disciplines, including classical genetics, molecular genetics, evolutionary biology, and population genetics.
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.
Most living organisms carry their genes as, and transmit them to offspring as, DNA, but some viruses carry only RNA.
Many phenotypes are determined by multiple genes and influenced by environmental factors.
The genetic code determines how the coding DNA sequence is converted into a protein sequence (via transcription and translation).
A DNA molecule or strand comprises four kinds of sequentially linked nucleotides, which together constitute the genetic alphabet.
Genes that appear together on the chromosomes of one species, such as humans, may appear on separate chromosomes in another species, such as mice.
A human that behaved in such a way would be described as "selfish," although ironically a selfish gene may promote altruistic behaviors.
In 1910, Thomas Hunt Morgan showed that genes reside on specific chromosomes.
In 1941, George Wells Beadle and Edward Lawrie Tatum showed that mutations in genes caused errors in certain steps in metabolic pathways.
The changes in populations that are considered evolutionary are those that are inheritable via the genetic material from one generation to another.
The ways that gene copies interact are explained by chemical dominance relationships.
A gene's most common allele is called the wild type allele, and rare alleles are called mutants.
Essentially, this view notes that the genes in existence today are those that have reproduced successfully in the past.
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.
The definition reflects the full complexity that has come to be associated with the term gene.
Errors during DNA replication may lead to the duplication of a gene, which may diverge over time.
The genotype of an individual organism is its specific genetic makeup (the specific genome).
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 encode the information necessary for constructing the multitude of proteins and RNA units needed to maintain an organism's existence, growth, action, and multiplication.
Genes are of central importance to the physical aspect of a living organism: A person's eye color, the breed of a dog, the gender of a horse.
Mayr (2001) states that "the reductionist thesis that the gene is the object of selection" is "invalid."
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.
Just as there are many factors influencing the expression of a particular DNA strand, there are many ways to have genetic mutations.
The symbols for human genes can also be applied to congruent genes in other species, such as the mouse.
Oswald Avery, Collin Macleod, and Maclyn McCarty showed in 1944 that DNA holds the gene's information.
The genes' protein products fulfill roles ranging from mechanical support of the cell structure to the transportation and manufacture of other molecules and the regulation of other proteins' activities.
Through the proteins they encode, genes govern the cells in which they reside.
Mendel's concept was finally named when Wilhelm Johannsen coined the word "gene" in 1909.
Not as dogmatic as Blyth, Henderson insisted only that haiku must be poems, and that the development of haiku in English would be determined by the poets.
The latter meaning of gene is the result of a more "material entity" than the first one.
According to this theory, adaptations are the phenotypic effects through which genes achieve their propagation.
The word gene was derived from Hugo De Vries' term pangen, itself a derivative of the word pangenesis, which Darwin (1868) had coined.
By convention, symbols for the different genes within a gene family all share a certain parallelism of construction.
Genes, the units of heredity in living organisms, are encoded in an organism's genetic material (DNA).
Often, many individual organisms share a gene; thus, the death of an individual need not mean the extinction of the gene.
Variants of a single gene are known as alleles, and differences in alleles may give rise to differences in traits, for example, eye color.
Once propagated to the next generation, this mutation may lead to variations within the population of a species.
The genetic code is essentially the same for all known life, from bacteria to humans.
The DNA sequences from which such RNAs are transcribed are known as genes for non-coding RNA or RNA.