The Test. Tests for Epstein-Barr virus (EBV) antibodies are used to help diagnose infectious mononucleosis (mono) if a person is symptomatic but has a negative mono test.he Test. Tests for Epstein-Barr virus (EBV) antibodies are used to help diagnose infectious mononucleosis (mono) if a person is symptomatic but has a negative mono test.
leaf scar. (botany). A mark on a stem, formed by secretion of suberin and a gumlike substance, showing where a leaf has abscised. 1  Facebook. 2  Twitter.
A leaf is an organ of a vascular plant and is the principal lateral appendage of the stem. The leaves and stem together form the shoot. Foliage is a mass noun that refers to leaves collectively.Typically a leaf is a thin, dorsiventrally flattened organ, borne above ground and specialized for photosynthesis.he epidermis is the outer layer of cells covering the leaf. It is covered with a waxy cuticle which is impermeable to liquid water and water vapor and forms the boundary separating the plant's inner cells from the external world.