The reproductive system is different from other body systems in that the reproductive system functions in the survival of a species while all other body systems function to ensure the survival of the individual.
It is a very interesting question - the technology is real and the research on eDNA published in a journal in 2017.
eDNA stands for enviornmental DMA sampling. It allows scientist to test water samples for the presence of the DNA of the invasive fish species. It is more effective than traditional methods of sampling because it does not require trapping or sighting of the invasive species. Water samples can be collected anywhere any time and the DNA results are as accurate and detailed as collected from the invasive species themselves. It provides a complete picture of what invasive species are there.
That easy..............<span>21 one is your technical answer according to todays rules but scientist used to think it was only 20 so 20 would be your answer</span>