When chordin binds to BMP-4, what effect does this have on the BMP-4 concentration gradient?
A - It sharpens the concentration gradient by degrading BMP-4 that diffuses to the dorsal half of the embryo.
B - It destroys the concentration gradient by degrading almost all BMP-4.
C - It sharpens the concentration gradient by inhibiting BMP-4 that diffuses to the dorsal half of the embryo.
D - It spreads out the concentration gradient by inhibiting BMP-4 activity where BMP-4 concentrations are highest.
E - It spreads out the concentration gradient by degrading BMP-4 where its concentrations are highest.
Answer: C - It sharpens the concentration gradient by inhibiting BMP-4 that diffuses to the dorsal half of the embryo.
Chordin inhibits BMP-4 activity in the dorsal part of the embryo.