Answer:
dyes used in negative staining have an. acidic chromagen (negatively charged chromophore) Examples of negative stains. NIgrosin and eosin. heat fixing smears can.
The three mechanisms which regulate the heart are endocrine, cardiovascular and Sinoatrial nodes.
The endocrine system consists of the glands and hormones of the human body. The cardiovascular system is the organ system which is responsible for the circulation of the blood around the body and the oxygenation of the body's tissues. The sinoatrial node (SA node) generates the electrical impulses and is considered the natural pacemaker of the heart.
I think it's A....hope that helps at least
Regeneration is the ability to gain something back again.
