Tastes are detected on the tongue through cells called gustatory cells. Gustatory cells have a variety of taste receptors. When bitterness is detected, the brain receives a message from these cells.
The taste of PTC is associated with a gene formed by the alleles responsible for tasting and non-tasting. These alleles are extremely important for us to be able to feel the different types of flavors.
The allele that codes for taste, is present in the taste buds of the tongue and can react with PTC molecules, allowing us to feel a characteristic bitter taste for that molecule. On the other hand, the non-gustatory allele is unable to react with PTC molecules. When these two alleles are combined within a genotype, the individual has a phenotype that allows sensitivity to the presence of the PTC flavor.
The coral reef is experiencing succession, so over time the coral will continue to die off gradually as the zooxanthellae algae leaves the coral polyps.
I believe the correct answer would be metabolism. This comprises all of the reactions inside organisms that allows them to sustain life. There are two categories of such namely, anabolism and catabolism. Hope this answers the question.
