1. http://www.flickr.com/photos/sparktography/388889060

2. http://www.flickr.com/photos/joanna8555/4011403215/

3. http://www.flickr.com/photos/themaxsons/2849159830/

4. ckr.com/photos/imortal/3707897327

5. http://www.flickr.com/photos/andresrueda/2983149263

7. http://www.flickr.com/photos/euthman/206766509
Cells

8. Virus
http://www.flickr.com/photos/36128932@N03/3338845735

9. http://www.flickr.com/photos/badlyricpolice/2209477536
Sore throat

10. http://www.flickr.com/photos/chrstphre/1862878322
Infection