Ascientist wants to know wheter a particular cell is round or rectangular. how should the scientist observe the overall shape of the cell?

The shape of a cell can easily be seen through a light microscope.

Explanation:

A microscope can be defined as a device which is used to visualize things which are otherwise not visible to the naked eye. The shape of a cell can be seen even through a light microscope. For example, an animal cell can be seen to have a round shape under the light microscope, a plant cell will be seen rectangular under the light microscope.

Other microscopes such as the electron microscope can even show the organelles present inside the cell.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.