单选题 1 The cells of a plant are organized into three tissue systems: dermal, vascular, and ground tissue. Each tissue system is continuous throughout the plant's body. The specific characteristics of each tissue, however, are different in the different organs of the plant.
2 The dermal tissue system is the "skin" of the plant. The dermal system, or epidermis, is a single layer of cells covering the entire body of the plant. The main function of the epidermis is to protect the plant. The epidermis also has specialized chamcteristics for the particular organs it covers. For example, the epidermis of leaves and stems has a waxy coating that helps the plant conserve water, and the epidermal cells near the tips of the plant's roots help the plant absorb water and nutrients from the soil.
3 The second tissue system--the vascular system--is the transportation system for water and nutrients. Vascular tissue also helps to support the plant's structure. The third system-- the ground tissue--makes up the bulk of a plant, filling all of the spaces between the dermal and vascular tissue systems. Ground tissue functions in photosynthesis, storage, and support.

单选题 How are the three tissue systems of a plant similar to each other?

单选题 Which of the following statements best describes the plant's epidermis?

单选题 Which type of tissue does a plant's body mainly consist of?.