The apical meristem is a region of actively dividing cells located at the tips of roots and shoots in plants. This tissue is responsible for the primary growth, allowing the plant to increase in length. The cells in the apical meristem are undifferentiated, meaning they can develop into various types of plant tissues. As the apical meristem produces new cells, they differentiate into specialized tissues such as xylem and phloem, which are essential for water and nutrient transport. This growth process is crucial for the overall development and health of the plant, enabling it to adapt to its environment.