Name and describe the role of each of the chambers in the rats heart. name the major artery and major vein connected to the heart. what is the function of each?

Easy:

The four chambers of the heart are the right and left atria, and the right and left ventricles. The main veins connected the heart are the superior and inferior vena cava, the main artery is the Aorta.

The first chamber, (the right atruim) recieves deoxygenated blood and forces it into the right ventricles which forces the blood into the lungs for oxygenation. Then the blood reenters the heart in the left atrium, which forces the blood into the left ventricle and then out the Aorta to the rest of the body.

sorry, but this question needed kind of a long answer to be answered correctly.

Step number 4 is least likely to occur meiosis 1