Metamorphic grade is a general term for describing the relative temperature and pressure conditions under which metamorphic rocks form. As the temperature and/or pressure increases on a body of rock we say that the rock undergoes prograde metamorphism or that the grade of metamorphism increases.he original rock that has undergone metamorphism is called the protolith. Protolith can be any type of rock and sometimes the changes in texture and mineralogy are so dramatic that is difficult to distinguish what the protolith was. 1  Note that diagenesis and weathering are also a changes in form that occur in rocks.
Within the nephron (the functional unit of the kidneys), filtration occurs in the glomerolus. The filtered fluid is called filtrate. Reabsorption of filtrate occurs in a few places within the nephron, however, the majority of reabsorption takes place in the proximal convoluted tube.
Im really confused as to where in the nephron of the kidney each of the three steps of urine formation occur the steps include: 1. glomerular filtration 2. tubular reabsorption 3.tubular secretion does glomerular filtration occur in the renal corpuscle, then the tubular reabsorption occur in the proximal...ubular secretions: It is the mechanism by which substances are removed from the blood and are directly added to the tubular fluids. Hydrogen ion, ammonium and drugs such as penicillin are some of the substances that move from the blood into the distal tubule of nephron. Secretions keep the blood from becoming acidic.