Apical meristems are regions of actively dividing cells located at the tips of roots and shoots in plants. These cells are responsible for the growth in length, allowing the plant to extend its roots deeper into the soil and its shoots higher into the air. The apical meristem produces new cells that differentiate into various types of tissues, such as leaf and stem tissues. This process is essential for the overall development and health of the plant, enabling it to adapt to its environment and optimize resource acquisition.