It is mostly likely the cell membrane.
The cell membrane is a structure of a cell composed of double layer of lipids and proteins. It surrounds a cell and separates the cytoplasm from its surrounding environment. The cell membrane is selectively permeable (semi-permeable), which means that it only lets certain molecules enter and exit. It can also control the amount of some substances that go into or out of the cell.
Answer:
TACGTACGTTAC (so the second one)
full coverage of the moon
Answer: The most serious of these mutations will be the insertion of 2 bases. Becasue the genetic code is read in triplets, a 2 base insetion will alter the reading frame of the code causing a frameshift mutation meaning every amino acid after the site of the mutation will be incorrect.
They have to have a higher density than water to have the ability to stay on the sea floor. Otherwise they would just float to the surface of the water