Final answer:
Mitosis in the apical meristem of a growing plant root tip drives primary growth, allowing for the continuous elongation of roots and absorption of water and minerals from the soil, guided by growth factors such as auxin and brassinosteroids.
Step-by-step explanation:
The role of mitosis in a growing plant root tip is crucial for the plant's continuous growth and development. Mitosis occurs in the apical meristem, a mitotically active zone of undifferentiated cells located at the root tip. This process allows for primary growth, which is imperative for the plant to access essential resources such as water and minerals from the soil. Within the root tip, cells divide rapidly and with increasing distance from the meristem, the rate of cell division and mitosis decreases. This contributes to the elongation of the plant roots. Growth factors, including auxin and brassinosteroids, regulate the cell division in root tips, with auxin concentrations being higher near the root tip and influencing the direction of root growth.
The rapidly dividing cells in the meristem give rise to all specialized tissues in the plant. Subsequent cell elongation and differentiation are key to root system development. This continuous cycle of cell division and elongation in the plant root tips facilitates the plant's adaptation and survival in its environment by enabling efficient uptake of water and nutrients.