Answer:
Perfectly in theory, except there is chance involved
Explanation:
The Punnet square is a diagram that allows scientists to predict the possible outcomes of the offspring when the genotypes of the parents are known. This is in line with Mendel's principles, and from a theoretical point of view would match up perfectly. However, it all works based on <em>probability</em>.
However, inheritance is always down to chance. Of your parents 2 alleles, you always have 50:50 chance of inheriting one of the allele. Overall, this is what is predicted in punnet squares.
However, think about flipping a coin. There is always 50:50 chance of getting heads, but that doesn't mean it is impossible to flip a coin and get tails 10 x in a row. It is just less likely. So in reality, observations might deviate from the theory.
To produce energy for the body
