Supernumerary body part considered to have lost much or all of their original function through evolution. These body parts can be classed as additional to the required functioning of the body. In human anatomy the vermiform appendix is sometimes classed as a vestigial remnant. Prosthesis is an artificial extension that replaces a body part, and cybernetics is the study of computer technology in relation to organisms which can include replacement or additional body parts. Body integrity identity disorder (BIID) is a psychiatric disorder in which a person thinks that they have one or more additional limbs than they should, despite having two arms
Human artificial chromosome Genetic material was then introduced as mentioned above, using the Cre-Lox recombination system. This particular study focused on changes in expression levels by leaving portions of the existing genomic DNA. By leaving existing telomeric and sub-telomeric sequences, they were able to amplify expression levels of genes coding for erythropoietin production over 1000-fold. This work also has large gene therapy implications, as erythropoietin controls red blood cell formation. HACs have been used to create transgenic animals for use as animal models of human disease and for production of therapeutic products. Human artificial chromosome A human artificial chromosome (HAC) is a microchromosome