5th wiki-link game

I chose the fourth link...

1).  Raltitrexed  http://en.wikipedia.org/wiki/Raltitrexed
2).  AstraZeneca  http://en.wikipedia.org/wiki/AstraZeneca
3).  Gastrointestinal  http://en.wikipedia.org/wiki/Human_gastrointestinal_tract
4).  Mouth  http://en.wikipedia.org/wiki/Mouth
5).  Mucous Membrane  http://en.wikipedia.org/wiki/Mucous_membrane
6).  Secretion  http://en.wikipedia.org/wiki/Secretion
7).  Gland  http://en.wikipedia.org/wiki/Gland
8).  Breast Milk  http://en.wikipedia.org/wiki/Breast_milk
9).  Newborns  http://en.wikipedia.org/wiki/Newborn
10).  Humans  http://en.wikipedia.org/wiki/Human
11).  Taxinomically  http://en.wikipedia.org/wiki/Taxonomy
12).  Taxis  http://en.wikipedia.org/wiki/Taxis
13).  Stimulus  http://en.wikipedia.org/wiki/Stimulus_(physiology)
14).  Organism  http://en.wikipedia.org/wiki/Organism
15).  Biology  http://en.wikipedia.org/wiki/Biology
16).  Organisms  http://en.wikipedia.org/wiki/Organism
17).  Biology  http://en.wikipedia.org/wiki/Biology

15 and 17 are the same...GAME OVER.