Pia mater
<span>Pia mater is a highly vascular tissue that cleaves
firmly to the surface of the brain and spinal cord. Pia mater protects the
central nervous system by nourishing the brain and allowing blood vessels to
pass through it. The inflammation of the pia mater can lead to meningitis</span>
A biological system is a complex network of biologically relevant entities. ... Examples of biological systems at the macro scale are populations of organisms. On the organ and tissue scale in mammals and other animals, examples include the circulatory system, the respiratory system, and the nervous system. source: google
DNA is being used as a template to make a molecule of mRNA.
Answer:
DNA:
Dexoyribonucleic acid is the genetic material of almost all the organisms except some virus. DNA contains deoxyribose sugar that lacks 2'OH group on second carbon. The nitrogenous base pair of DNA are adenine, guanine, thymine and cytosine. DNA cannot acts as an enzyme.
RNA:
Ribonucleic acid is present as genetic material in few viruses only. RNA contains oxyribose sugar that has 2'OH group at second position. The nitrogenous base pair of RNA are adenine, guanine, uracil and cytosine. RNA can acts as any enzyme in biological reactions.