Answer:
Prokaryotic cells have a cell wall, Eukaryotic cells do not. Eukaryotic cells are much larger an are in fact more complex then Prokaryotic cells. Eukaryotic cells have a true nucleus bound by a doubled membrane. Prokaryotic cells have no nucleus.
Explanation:
All forms of RNA are intermediate molecules that are fabricated within DNA to perform cellular functions.
mRNA - messenger RNA carries selected portions of DNA used to fabricate polypeptides used to fabricate amino acids for protein.
tRNA - transfer RNA is comprised of select genetic code and transfers amino acids to ribosomes for assembly
rRNA - ribosomal RNA is comprised of select genetic code and makes the ribosomes
RNA is highly mutatable, highly reactive, non-reproductive, and highly specialized metabolically, and consequently totally unsuitable for consideration of any pre-DNA senario being posited for the origin of life.
Very, very rare. Uranium used in power plants is typically only 3% U-235 (the explosive stuff), while bomb-grade uranium is nearly pure U-235. Simply, the concentration of U-235 in reactor-grade uranium is too small to start a chain reaction and detonate like a bomb.
A Solid has a fixed mass.