A. umbilical cord is the answer
Answer:
it cannot be easily degraded in our environment.Like humans, animals and plants are exposed to PBTs in the environment through air, water and food. ... Persistent bioaccumulative toxic substances (PBTs) are chemicals that do not degrade easily in the environment.
It would be considered an opioid.
The answer for the question is the Apical meristem.
Growth in plants occurs as the stems and roots lengthen. Some plants, especially those that are woody, also increase in thickness during their life span. The increase in length of the shoot and the root is referred to as primary growth. It is the result of cell division in the shoot apical meristem.