Final answer:
Roots and shoots are referred to as an independent system because they have the ability to develop and grow on their own. They can produce new modules, such as branch roots and branch shoots, which replicate the original axis. Apical meristems facilitate this independent growth.
Step-by-step explanation:
The roots and shoots of a plant are referred to as an independent system because they have the ability to develop and grow on their own. They are modular structures that can produce new modules, such as branch roots and branch shoots, which are replicas of the original root and shoot axis. This independent growth is facilitated by apical meristems, which are responsible for primary growth in plants.
For example, the shoot apical meristem can generate branches, and these branches can generate more branches, creating a recursive structure. Similarly, the root apical meristem can produce branch roots, resulting in the growth and expansion of the root system. These independent systems allow plants to adapt and respond to their environment.