Определение гена (Важно сравнить 2009 и 2015)

Ген (др.-греч. γένος — род) — структурная и функциональная единица наследственности живых организмов. Ген представляет собой участок ДНК, задающий последовательность определённого полипептида либо функциональной РНК. Гены (точнее, аллели генов) определяют наследственные признаки организмов, передающиеся от родителей потомству при размножении. Среди некоторых организмов, в основном одноклеточных, встречается горизонтальный перенос генов, не связанный с размножением.

Ген-структурная и функциональная единица наследственности, контролирующая развитие определенного признака или свойств.
Ген — материальный носитель наследственной информации, совокупность которых родители передают потомкам во время размножения. В настоящее время, в молекулярной биологии установлено, что гены — это участки ДНК, несущие какую-либо целостную информацию — о строении одной молекулы белка или одной молекулы РНК. Эти и другие функциональные молекулы определяют рост и функционирование организма.

2015 Wiki

Gene is a locus (or region) of DNA that encodes a functional RNA orprotein product, and is the molecular unit of heredity. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. Most biological traits are under the influence of polygenes (many different genes) as well as the gene–environment interactions. Some genetic traits are instantly visible, such as eye colour or number of limbs, and some are not, such as blood type, risk for specific diseases, or the thousands of basic biochemicalprocesses that comprise life.

Genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a protein, which cause different phenotypetraits. Colloquial usage of the term "having a gene" (e.g., "good genes," "hair colour gene") typically refers to having a different allele of the gene. Genes evolve due to natural selection or survival of the fittest of the alleles.

The concept of a gene continues to be refined as new phenomena are discovered. For example, regulatory regions of a gene can be far removed from its coding regions, and coding regions can be split into several exons. Some viruses store their Jeanome in RNA instead of DNA and some gene products are functional non-coding RNAs. Therefore, a broad, modern working definition of a gene is any discrete locus of heritable, genomic sequence which affect an organism's traits by being expressed as a functional product or by regulation of gene expression.

2009 Wiki

gene is the basic unit of heredity in a living organism. All living things depend on genes. Genes hold the information to build and maintain their cells and pass genetic traits to offspring. A modern working definition of a gene is "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 ". Incorrect colloquial usage of the term gene may actually refer to an allele: a gene is the basic instruction, a sequence of DNA, while anallele is one variant of that instruction.

The notion of a gene has evolved with the science of genetics, which began whenGregor Mendel noticed that biological variations are inherited from parent organisms as specific, discrete traits. The biological entity responsible for defining traits was termed a gene, but the biological basis for inheritance remained unknown until DNA was identified as the genetic material in the 1940s. All organisms have many genes corresponding to many different biological traits, some of which are immediately visible, such as eye color or number of limbs, and some of which are not, such as blood type or increased risk for specific diseases, or the thousands of basic biochemical processes that comprise life.

In cells, a gene is a portion of DNA that contains both "coding" sequences that determine what the gene does, and "non-coding" sequences that determine when the gene is active (expressed). When a gene is active, the coding and non-coding sequences are copied in a process called transcription, producing an RNA copy of the gene's information. This piece of RNA can then direct the synthesis of proteins via the genetic code. In other cases, the RNA is used directly, for example as part of the ribosome. The molecules resulting from gene expression, whether RNA or protein, are known as gene products, and are responsible for the development and functioning of all living things.

In more technical terms, a gene is a locatable region of genomic sequence, corresponding to a unit of inheritance, and is associated with regulatory regions, transcribed regions and/or other functional sequence regions. The physical development and phenotype of organisms can be thought of as a product of genes interacting with each other and with the environment. A concise definition of a gene, taking into account complex patterns of regulation and transcription, genic conservation and non-coding RNA genes, has been proposed by Gerstein et al.: "A gene is a union of genomic sequences encoding a coherent set of potentially overlapping functional products".