Selective breeding and genetic engineering GapFill

 InbreedingGenetic selectionSelective breedingGenetic engineering has been in place for centuries so that humans can develop the most useful organisms for their needs. During this process, humans identify an organism with a valuable trait, such as a plant with large flowers or domestic dogs with a gentle nature, and choose the best individuals to breed together to form the next generation. 

A more complex way that humans can make the most of their valuable species is by  fertilisationdifferentiationgenetic engineeringcloning, where genes are inserted into the DNA of developing organisms to modify their  enzymesproteinsallelesgenomes. A  divisionrestrictiondigestionmultiplication enzyme is used both to remove a desired gene and to open up a bacterial plasmid, and the same  scissor marksjigsaw punchessticky endszigzag pieces that are created by these cuts can be rejoined with  hydrolaseligasehelicaseoxidase.

Plant crops have been engineered to be resistant to some diseases, or to produce bigger fruits in order to feed a growing population. Crops that have undergone this technique are called  homozygotesGMGEclones, but there are many concerns about the effects of these organisms on humans and ecosystems. There are also concerns with the use of  fertilisersantibioticsinsecticidesnitrates to control pests, as some of them kill a range of species, not just the target species. One alternative for controlling insects (and also weeds) is to use  meiotic divisiongenetic cloningbiological controlselective breeding, i.e. other predatory species or herbivores. 

Another way to maximise crop yields is to make use of  fungicidesirrigatorsfertilisersinsecticides, which usually contain high levels of nitrogen, potassium and phosphorus. However, overuse of these chemicals can cause them to leach into nearby  fieldscavesgreenhouseswater sources, polluting them and causing potential health concerns.