The ear cannot hear, but it resembles an ear cosmetically. Functional urinary bladders have been made for Beagle dogs. The next step will be human bladders. New heart valves for sheep have been grown from the animals arteries. The alves worked and the research animals lived for several months.
Scientists hope to be able to grow complicated organs such as hearts, livers and kidneys.
The challenge lies in getting the heart to beat, having enough oxygen and nutrients transferred to all parts of the tissue in major organs, and having the grown organ perform the correct chemical reactions as in a kidney, for example. A true copy of yourself can be used as an organ donor in case you need it. In 1997, the cloned sheep, Dolly, was born, and since then, calves and mice have been cloned. So the method works.