The moment it is exposed into the environment
It is the nucleus that contains DNA and controls the functions of the cells
Answer:
Electron microscope would be used for if,
C) details of cell structures needed to be distinguished.
Explanation:
- The general principal of electron microscopy is analogous to light microscopy except that it uses electrons to analyse the specimen instead of light.
- Electron microscopy focuses a beam of electron on the target sample and records the difference in absorption by different surfaces.
- Electron microscopy is used to get the detailed structure of cells and surface features of various viruses and bacteria.
- However, it is not possible to view living biological samples through electron microscope because high velocity electron have immense energy to kill living cells.
- These samples are thus, fixed and then viewed.
Ductus Arteriosus is a blood vessel normally present in fetuses during development. The blood vessel is designed to bypass the pulmonary artery and brings blood to the Descending Aorta, as the fetus cannot breath through the lung (being as they are fluid filled). This is normally not a problem because oxygenated blood comes from the mother's blood supply.
Patent Ductus Arteriosus, is what happens when that vessel does not close. While not as dangerous as other congenital defects. However, because there is still a bypass, blood that normally need to be oxygenated by going through the pulmonary arteries to the lungs, can be diverted and placed into the blood stream without vital oxygen. This condition may eventually lead to CHF (congestive Heart Failure) and Pulmonary Hypertension if not treated.
