During early embryonic development, a protein called sonic hedgehog is released from a cell and travels in a small gradient through the interstitial fluid only to nearby cells. This helps to establish the path and direction of development for the nervous system and limbs. Knowing this, sonic hedgehog must be a(n)________ signal.
A)endocrine
B)paracrine
C)autocrine
D)nervous

Question

Quizplus · Accepted Answer

Sonic hedgehog is a paracrine signal because it only travels to nearby cells and does not enter the bloodstream to affect distant cells like an endocrine signal would.

During Early Embryonic Development, a Protein Called Sonic Hedgehog Is