Mitochondria are membrane-bound cell organelles (mitochondrion, singular) that generate most of the chemical energy needed to power the cell's biochemical reactions. Chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP).
Human forelimbs is used for a variety of functions, such as for eating.
Similarities: They are all made from the same basic anatomical structure classified as homologous structures.
They all have this structure inherited from a common ancestor.
An example could be oil (olive, almond)