Genetics is the study of genes, heredity, and genetic variation in living organisms. It is generally considered a field of biology, but it intersects frequently with many of the life sciences and is strongly linked with the study of information systems. The father of genetics is Gregor Mendel, a late 19th-century scientist and Augustinian friar. Mendel studied 'trait inheritance', patterns in the way traits were handed down from parents to offspring. He observed that organisms (pea plants) inherit traits by way of discrete units of inheritance.
Razors come in two varieties, dual bevel or single bevel. They are identified by whether both sides are angled, which creates a side-view like an isosceles triangle, or just single-angled. The single-angled is straight one one side and angled on the other. When talking about sharpening blades to a particular angle, the sharpening needs to occur equally to both sides of the dual-angle blade. For instance, the ideal shave is achieved with a 15 to 20 degree bevel angle.
Paired instruments are also designated as right or left. In lateral cutting instruments the one used to cut from right to left is termed right; in direct cutting instruments with right and left bevels, the one having the bevel on the right side of the blade as it is held with the cutting edge down and pointing away from the observer is termed right.