Genetics

The basic structural and logical unit of genetic inheritance is the gene. DNA is the material that makes up genes. Some genes serve as blueprints for the production of proteins. Many genes, however, do not code for proteins. Genes in humans range in size from a few hundred to over 2 million DNA bases. Humans have between 20,000 and 25,000 genes, according to the Human Genome Project, an international research attempt that collaborated to determine the sequence of the human genome and identify the genes that it includes.

Each person is born with two copies of each gene, one from each parent. The majority of genes are identical in all people, but a small number of genes differ slightly. Alleles are variants of the same gene with minor differences in DNA base pair. These minor differences make a contribution to the individuality of each individual's health characteristics.

Genes are given unusual identifiers by scientists to keep track of them. Genes are given signifiers, which are short configurations of letters that embody an altered version of the gene name, because gene names can be long. The cystic fibrosis transmembrane conductance regulator, for example, is a gene on chromosome 7 that has been linked to cystic fibrosis. Its name is CFTR.

The DNA can be effectively implanted into the host organism or into a cell that is merged or hybridized with the host. This method utilizes recombinant nucleotide techniques to create new combinations of heritable genetic makeup, which is then incorporated either implicitly via a vector system or directly via micro-injection.

Traditional mating, in vitro fertilization, implantation of mutations, mutagenesis, and cell fusion techniques that do not use recombinant nucleotides or a genetically modified organism are not usually considered genetic engineering. Selective breeding is included in some broad definitions of genetic engineering. Although not considered genetic engineering, cloning and stem cell research are closely related, and genetic engineering can be used in both. Synthetic biology is a new field that goes beyond genetic engineering by introducing artificially synthesized material into living organisms.

Genetically modified organisms are plants, animals, or microorganisms that have been altered through genetic engineering.  Transgenic organisms are created when genetic material from another species is added to the host. The resulting organism is called cisgenic when genetic material from the very same lifeforms or a species that can naturally breed with the host is used. A knockout organism is created when genetic engineering is used to remove genetic material from the target organism.