What type of tissue is responsible for the transport of organic food materials in plants?

The transport of organic food materials in plants is primarily the responsibility of phloem tissue. Phloem consists of specialized cells that facilitate the movement of nutrients, particularly sucrose and other carbohydrates produced during photosynthesis, from the leaves (where they are synthesized) to other parts of the plant, such as roots or growing tissues. This process is known as translocation, which is essential for providing energy and building blocks for growth and development throughout the plant.

Phloem is structured to enable efficient transport, with sieve tube elements that allow for the flow of sap and companion cells that assist in loading and unloading materials. The role of phloem is crucial for plant health, as it supports the overall metabolic functions necessary for plant survival.

The other types of tissues mentioned do not perform this function. For example, xylem is responsible for the transport of water and minerals from the roots to the rest of the plant. Collenchyma provides structural support but is not involved in transport. Periderm is related to the protective layer of plants but does not play a role in nutrient transport. Thus, phloem is the correct choice for its specific function in the movement of organic food materials.