What microscope is used to study dna molecules?
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stm

DNA molecules can be viewed through Scanning Tunneling Microscopy (STM). Within this type of microscope option, DNA molecules can be ultimately seen at atomic levels and at greater depth to identify the differences between various DNA molecules.

since there are no options posted i'll give you a few examples.

a dolphin's flipper, bird's wing, cat's leg.

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.