Answer:
They are typically smaller than eukaryotic cells.
The DNA of a prokaryotic cell is contained in the nucleoid.
Explanation:
There are several ways in which prokaryotic cells are different from eukaryotic cells. Firstly, they are generally smaller in size, their organelles are not membrane bound, and they have no nucleus. They, however, share commonalities with eukaryotic cells including the presence of a bilipid plasma membrane, presence of ribosomes and DNA.
One fourth means (one half) of (one half) .
So the 18 months must be two half-lifes.
The half-life of this particular isotope is 9 months.
Answer: During the Cambrian Explosion of Animal Life
