$500 Bill. The Treasury minted several versions of the $500 bill, featuring a portrait of President William McKinley on the front. The last $500 bill rolled off the presses in 1945, and was formally discontinued 24 years later in 1969. Like all the bills featured here, the $500 bill remains legal tender.
Confidence votes 21. Selective breeding has been a way of enhancing preferable genetic qualities in mainly dogs, cats and horses. Often the results can cause mild to severe problems.For example ;breeding for the flat face of the pekingese can cause breathing problems and jaw and teeth deformities.ften the results can cause mild to severe problems.For example ;breeding for the flat face of the pekingese can cause breathing problems and jaw and teeth deformities.
New varieties. Natural selection and selective breeding can both cause changes in animals and plants. The difference between the two is that natural selection happens naturally, but selective breeding only occurs when humans intervene. For this reason selective breeding is sometimes called artificial selection. Different varieties of plants and animals with desired characteristics can be developed by selective breeding. For example: 1  cows that produce lots of milk. 2  chickens that produce large eggs.