meristeemi

Meristeemi refers to actively dividing plant tissues. These tissues are responsible for plant growth and development. Meristematic cells are typically small, undifferentiated, and have thin cell walls. They contain dense cytoplasm and large nuclei, with small or absent vacuoles. Meristems are found in specific regions of the plant, such as the tips of roots and shoots, and in the vascular cambium and cork cambium.

There are two main types of meristems: apical meristems and lateral meristems. Apical meristems are located at the apex (tip) of roots and shoots and are responsible for primary growth, which increases the length of the plant. This primary growth leads to the formation of new leaves, flowers, and stems. Lateral meristems, such as the vascular cambium and cork cambium, are found in woody plants and are responsible for secondary growth, which increases the girth or diameter of the plant. Secondary growth produces secondary xylem and secondary phloem, contributing to the strength and support of the plant.

Meristematic activity is regulated by a complex interplay of hormones, environmental factors, and genetic signals. Hormones like auxins and cytokinins play crucial roles in promoting or inhibiting cell division and differentiation within meristems. Understanding meristems is fundamental to plant biology, as it explains how plants grow, adapt to their environment, and develop their characteristic structures.