Human and apes have 5 fingers that are used for grasping objects, so they have the same function, but they also have a common ancestor and are closely related, that means that this is an example of homologous structures. In evolutionary biology, the term homologous structures means that there are organs and skeletal elements of animals and organisms, that by virtue of their similarity, suggest their connection to a common ancestor.
Rabbits,elk, and so forth rabbits have grass and roots
How old is Darren? we need to know his age before we answer
To be able to compare the results to a sample without any of the independent variable added.