It is the fundamental, physical, and functional unit of heredity. Supplement. It is because a gene is a segment of DNA (on a specific site on a chromosome) that is responsible for the physical and inheritable characteristics or phenotype of an organism.
By Regina Bailey. Definition: DNA (deoxyribonucleic acid) is a type of macromolecule known as a nucleic acid. It is shaped like a twisted double helix and is composed of long strands of alternating sugars and phosphate groups, along with nitrogenous bases (adenine, thymine, guanine and cytosine). DNA contains the genetic information necessary for the production of other cell components, organelles, and for the reproduction of life. Information contained within the genetic code is passed from DNA to RNA to the resulting proteins. Genes contain the codes for the production of specific proteins. The information contained within DNA is not directly converted to proteins, but must first be transcribed in a process called DNA transcription. This process takes place within the nucleus of our cells. Genes exist in alternative forms called alleles. Alleles determine distinct traits that can be passed on from parents to offspring. gene. A segment of DNA, occupying a specific place on a chromosome, that is the basic unit of heredity. Genes act by directing the synthesis of proteins, which are the main components of cells and are the catalysts of all cellular processes. 1. gene - (genetics) a segment of DNA that is involved in producing a polypeptide chain; it can include regions preceding and following the coding DNA as well as introns between the exons; it is considered a unit of heredity; genes were formerly called factors. cistron, factor. Chromatin is the “packaged” form of DNA in the nucleus and its regulation is central to transcription – creating the RNA copy of a DNA sequence. Chromatin helps assure that the DNA/RNA copy is precise – any deviation can result in stunted gene expression or proteins that no longer function properly.  Definition: Genes are segments of DNA located on chromosomes. Genes exist in alternative forms called alleles. Alleles determine distinct traits that can be passed on from parents to offspring. The process by which genes are transmitted was discovered by Gregor Mendel and formulated in what is known as Mendel's law of segregation Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA (rRNA) genes or transfer RNA (tRNA) genes, the product is a functional RNA. Promoter – a nucleotide sequence that enables a gene to be transcribed. The promoter is recognized by RNA polymerase, which then initiates transcription. In RNA synthesis, promoters indicate which genes should be used for messenger RNA creation – and, by extension, control which proteins the cell manufactures. Gene. Definition. noun, plural: genes. (cell and molecular biology). The fundamental, physical, and functional unit of heredity. Supplement. It is because a gene is a segment of DNA (on a specific site on a chromosome) that is responsible for the physical and inheritable characteristics or phenotype of an organism. It also specifies the structure of a protein, and an RNA molecule. A gene is formerly called a factor. Transcription [edit]. Generation of RNA from DNA is known as transcription. In other word transcription is the process of creating a complementary RNA copy of a sequence of DNA. During transcription, a DNA sequence is read by RNA polymerase, which produces a complementary, antiparallel RNA strand. Promoter – a nucleotide sequence that enables a gene to be transcribed. The promoter is recognized by RNA polymerase, which then initiates transcription. In RNA synthesis, promoters indicate which genes should be used for messenger RNA creation – and, by extension, control which proteins the cell manufactures.
http://biology.about.com/od/geneticsglossary/g/DNA.htm http://biology.about.com/od/geneticsglossary/g/Genes.htm http://www.thefreedictionary.com/gene http://www.wistar.org/our-science/research-areas/genes-gene-expression-dna-biology http://biology.about.com/od/geneticsglossary/g/Genes.htm https://en.wikibooks.org/wiki/An_Introduction_to_Molecular_Biology/Gene_Expression http://www.biology-online.org/dictionary/Gene https://en.wikibooks.org/wiki/An_Introduction_to_Molecular_Biology/Gene_Expression
what is a gene in biology