Best Answer: The definitions will tell you the differences. The nucleus, in a eukaryotic cell, contains the DNA for cell function and, therefore, is the control center of the cell (It is NOT a brain).It also contains the nucleolus which is the site where ribosomes are manufactured.he nucleus, in a eukaryotic cell, contains the DNA for cell function and, therefore, is the control center of the cell (It is NOT a brain). It also contains the nucleolus which is the site where ribosomes are manufactured.
The heart contains four chambers. The two upper chambers are the atria and the two lower chambers are the ventricles. On the cranial surface of each atrium is a pouch-like appendage called an auricle which is thought to increase the capacity of the atrium slightly.
The heart has four chambers. The upper two chambers are the atria, and the lower two are the ventricles (Figure A). The chambers are separated by a wall of tissue called the septum. Blood is pumped through the chambers, aided by four heart valves. The valves open and close to let the blood flow in only one direction. Congenital defects may involve a valve, a chamber, the septum, an artery or blood flow issues.