The histone proteins are among the most slowly evolving proteins. For example, a histone protein called histone H4 in cows and peas differs by only 2 amino acids among a total of about 100. A reason why histone proteins evolve so slowly is their function: These proteins bind with the negatively charged phosphate groups in double-stranded DNA, so the proteins must be rich in the basic amino acids lysine and arginine. Therefore, these amino acids cannot be replaced without disrupting the histone's structure and function. a) True
b) False

preservation because he preserves part of the land and preserves means save

explanation:

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

characteristics of hydrocarbons

to figure the total magnification of an image that you are viewing through the microscope is really quite simple. to get the total magnification take the power of the objective (4x, 10x, 40x) and multiply by the power of the eyepiece, (usually 10x)