Which layer of plant tissue is characterized by densely packed elongated cells?

The palisade layer is a key component of plant anatomy, particularly in leaves, and is characterized by its structure of tightly packed elongated cells. These cells are arranged perpendicular to the leaf surface, allowing for maximum exposure to sunlight, which is essential for photosynthesis. This arrangement enables the cells to contain a high density of chloroplasts, which are responsible for capturing light energy. The palisade layer is typically found just beneath the upper epidermis of the leaf, and its design is optimized for efficient light absorption.

In contrast, the spongy layer is composed of loosely arranged cells with air spaces that facilitate gas exchange, which distinguishes it from the densely packed arrangement seen in the palisade layer. Xylem and phloem, on the other hand, are vascular tissues responsible for the transport of water and nutrients within the plant, and they do not typically have the elongated structure found in the palisade layer. The focus on maximizing light absorption in the palisade layer highlights its crucial role in the plant's ability to perform photosynthesis efficiently.