(12) phospholipids in a membrane (lipid). Public Domain.
(13) http://commons.wikimedia.org/wiki/Image:Algues_eau_douce.jpg
http://www.flickr.com/photos/squeezyboy
http://www.flickr.com/photos/aussiegall/714115502/
http://www.flickr.com/photos/ajpierro/240581/Composite image made from
five different images.. (a) Copyright holder allows use for any purpose (b) CC-BY-SA
1.0 (c) CC-BY 2.0 (d) CC-BY 2.0 (e) CC-BY 2.0.
(14) CK-12 Foundation.
http://commons.wikimedia.org/wiki/Image:ProteinStructures.gif. CC-BY-SA
3.0.
(15) Angela Sevin.http://www.flickr.com/photos/angela7/294746254/. CC-BY.
(16) Hernan Vargas.http://www.flickr.com/photos/hvargas/2114683166/.
CC-BY-SA 2.0.
(17) http://commons.wikimedia.org/wiki/Image:Atom.svg. GNU-FDL.
(18) Epithelial cells. GNU-FDL.
(19) Just chaos.http://www.flickr.com/photos/7326810@N08/1478892479/. CC-BY
2.0.
(20) Adenosine.http://en.wikipedia.org/wiki/Image:Tevenphage.png. CC-BY-SA
2.5.
(21) EPA.http://commons.wikimedia.org/wiki/Image:Pediastrumboryanum.jpg.
Public Domain.
(22) evamol.http://www.flickr.com/photos/evamol/989313624/. CC-BY.
(23) http://commons.wikimedia.org/wiki/Image:Darwin%27s_finches.jpeg. Public
Domain.
(24) http://en.wikipedia.org/wiki/Image:Activation2_updated.svg. GNU-FDL.
(25) Bill Denney. Fungus on log. CC-BY-SA 2.0.
(26) http://commons.wikimedia.org/wiki/Image:Chimotrypsin-inhib.png. Public
Domain.
(27) Ernesto Andrade.http://www.flickr.com/photos/dongkwan/2294951493/. CC-BY
2.0.
(28). CC-BY-SA 3.0.