From the deepest to most superficial: pia mater, arahnoid, dura mater
They are both known to be heavy, hydrogen is one of the two stable isotopes of deuterium
This depends... I live in Southern Michigan, which is deciduous forest because they cover most of the Northern US.
Fat (lipid) molecules are made up mostly of long chains of carbon atoms.
For a fat molecule to be considered saturated, the carbon chain must have only single bonds between them.
Schematically, they look like -C-C-C-C- ...
If the carbon chain contains one or more double bonds, such as -C=C-C-C, then the given lipid molecule is unsaturated.
If a lipid molecule (fatty acid) contains exactly one double bond in its chain, and the rest are single bonds, it is then called monosaturated. It is a more healthy food source than saturated fats.
Saturated fat are generally solid at room temperatures. Examples include lard, butter, mostly from animal sources. However, coconut oil (solid at room temperatures as well) is a saturated fat.
DNA is a negatively-charged molecule. Also cell membranes are negatively charged. The problem would be how to push this charges together? I<span>f you put some CaCl2 into the mixture, the CaCl2 will "split" giving 2Cl- and Ca2+. This last ion will be attracted by the negatively charged DNA and will "cover" it, hiding its negative charge. Hope this answers the question.</span>