If we want to use the words of others, we need to use quotation marks and have a citation.
Martin Luther King said, "I have been to the mountaintop!" (King).
One solution, according to Prof. Anita Henderson is to freeze the tissue immediately instead of waiting ("The Fight to Cure Cancer" 3).
Photo by Matt Shiffler Photography on Foter.com / CC BY-NC-SA
If it's copyrighted, we should avoid using it. If we must, you will need to cite it in the MLA way.
If it's public domain, you don't have to cite at all, but you could link to the place you got it.
If it's Creative Commons License, you'll need to give credit in the Creative Commons way.
What if I add this?