Final answer:
Hysteresis is observed when a tissue is cyclically loaded and unloaded, resulting in a lag or delay in its response.
Step-by-step explanation:
Hysteresis is observed when a tissue is cyclically loaded and unloaded. This means that when a tissue is subjected to repeated cycles of loading and unloading, it does not return to its original state or properties. Instead, there is a lag or delay in the response of the tissue, causing it to exhibit a memory of the previous loading cycles.