Answer:
It attempts something else to reach the same end product.
Plants cell unable to do photosynthesis use the reaction from our cells creating ATP. There are some other examples I'm sure but I can't remember them of the top of my head.
All galaxies have a dense core of stars. Spiral galaxies, however, have arms that are often visible. There are two kinds of spiral galaxies: barred, where there appears to be a line running from arm to arm through the core, and <span>ordinary, where there is no bar. @Badbunnyhunny</span>
Since homologous means same structure different functions, it shows that animals evolve to have the same structure as their ancestors but, have different uses to the part