Urinal system aka renal system
1) determine the probability of individuals inheriting a disease
2) In the future, new genetic mutations will arise, and knowing to understand genetics would be important in helping analyze the problem/mutation in genetic recombination.
3) Genetics allows us to link diseases to one another (pedigrees) by analyzing if they are recessive, dominant, and/or autosomal, this allows us, as scientists to be able to identify and classify future diseases, and to determine their inheritance pattern, in the future.
Well our bodies get the energy they need from food through metabolism. So the answer is food