Xolloid is a(n)
A - Protease
B - Nucleic acid
C - Inhibitor
D - Receptor
E - Signaling molecule
Answer: A - Protease
Xolloid is a protease which degrades chordin and it sharpens the concentration of BMP-4. It is produced in the ventral portion of the embryo and is not effective in the dorsal side because chordin is so abundant.