In botany, plant cuticles are protective, hydrophobic, waxy coverings produced by the epidermal cells of leaves, young shoots and all other aerial plant organs.Cuticles minimize water loss and effectively reduce pathogen entry due to their waxy secretion.he cuticle both prevents plant surfaces from becoming wet and helps to prevent plants from drying out. Xerophytic plants such as cactus have very thick cuticles to help them survive in their arid climates.
radiometric dating. n. 1. (Archaeology) any method of dating material based on the decay of its constituent radioactive atoms, such as potassium-argon dating or rubidium-strontium dating. Also called: radioactive dating.
With the exception of Carbon-14, radiometric dating is used to date either igneous or metamorphic rocks that contain radioactive elements such as uranium. And even though various radioactive elements have been used to date these rocks, for the most part, the methods are basically the same. They consist of measuring the amount of radioactive (mother) element and comparing it to the amount of stable (daughter) element. A discussion of the Uranium/Lead method follows. Uranium is radioactive, which means it is in the process of changing from an unstable element into a stable one.