In a red blood cell, the control center is the nucleus. A mitochondria is not a nucleus. It is another organelle that produces energy for the cell.
It is the rib cage (thoracic cage)
DNA<span> is transcribed into RNA, 1 base of </span>DNA<span> corresponds to 1 base of RNA, this 1 to 1 relation is not used in the translation to </span>protein<span>. During this translation, 1 amino acid is added to the </span>protein strand for every 3 bases in the RNA so b<span>efore double stranded </span>DNA<span> is turned into </span>protein<span> it first goes through a process called transcription. </span>
The answer to this question is : <span>They tolerate both freshwater and salt water.</span>