Final answer:
Loss of IFT-A would impair Hedgehog signaling upon the addition of the Hedgehog ligand, resulting in defective signal transduction and incomplete perception of the Hedgehog signal.
Step-by-step explanation:
The loss of IFT-A (intraflagellar transport-A) would greatly influence Hedgehog signaling upon the addition of the Hedgehog ligand. IFT-A is involved in the transport of Hedgehog proteins within cilia, and disruptions in IFT-A can result in defective Hedgehog signaling. Without IFT-A, the Hedgehog ligand would not be properly transported within the cilia, leading to impaired signal transduction and incomplete perception of the Hedgehog signal.