Scientists have found that the hedgehog signaling pathway is active in embryos during the early development of the neural tube, motor neuron specification, left-right symmetry, body plan, limbs, and retinas. In the 1950s, sheep feeding on the corn lily (Veratrum species) in mountain pastures gave birth to a number of lambs with only one eye. These one-eyed lambs were explained when the compound, now known as cyclopamine, was discovered in the corn lily. Explain how a failure to have cell division occur at a critical time during development could lead to lambs with one eye