Answer:
3: A device that uses radioactive fluid to determine the active areas of the brain
Explanation:
A positron emission tomography (PET) scan is an imaging test that helps reveal how your tissues and organs are functioning. A PET scan uses a radioactive drug (tracer) to show this activity. This scan can sometimes detect disease before it shows up on other imaging tests.
Depending on the type of exam, the radiotracer is injected, swallowed or inhaled as a gas. It eventually accumulates in the area of the body under examination. A special camera or imaging device detects radioactive emissions from the radiotracer. The camera or device produces pictures and provides molecular information.
I believe the most VALID answer to your question is "Homeostasis".
Organisms that carry out homeostasis do so in order to maintain a constant, optimum environment for the cells within their body.
<span><span>B)
proteins
</span>Proteins are biological macromolecule and mostly composed of enzymes. In biochemical reactions, it is mostly triggered by enzymes. Enzymes are important components in the process that involves metabolism and digestive functions, further, most of these enzymes are proteins. </span><span>Proteins play a role in the physical make-up of a cell or acts as a cytoskeleton –maintains cell shape and figure. These proteins plays different roles and works with nucleic acids and other macromolecules in the cells including cell cycle, cell adhesion, immune response and cell indicators. <span>
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I don’t understand the question! context?