The basic structure of a leaf that can be observed under a microscope includes the following components:

1. Epidermis: The outermost layer of the leaf, consisting of a single layer of cells. It helps in protecting the inner tissues of the leaf.

2. Cuticle: A waxy layer present on the outer surface of the epidermis that helps in reducing water loss from the leaf.

3. Stomata: Small openings present in the epidermis that allow for the exchange of gases (such as oxygen and carbon dioxide) between the leaf and the environment.

4. Palisade Mesophyll: A layer of elongated, tightly packed cells located just below the upper epidermis. These cells contain numerous chloroplasts and are responsible for photosynthesis.

5. Spongy Mesophyll: A layer of loosely arranged cells present below the palisade mesophyll. These cells also contain chloroplasts and allow for the exchange of gases and storage of water and nutrients.

6. Vascular Bundles: These are composed of xylem and phloem tissues and are responsible for transporting water, minerals, and sugars throughout the leaf.

7. Guard Cells: Specialized cells surrounding the stomata that regulate their opening and closing, thus controlling the exchange of gases and water vapor.

8. Veins: These consist of vascular bundles surrounded by supportive tissues and are responsible for providing structural support to the leaf as well as transporting water and nutrients.

These structures work together to perform various functions such as photosynthesis, gas exchange, and transportation of water and nutrients in the leaf.