This is most likely the result of OXIDATION. When an apple is cut open, the cells of the apple are exposed to the atmosphere, the in built defense mechanism inside the apple that is supervised by certain enzymes react to this situation by reacting with oxygen and creating an oxidized brown layer which protects the apple from foreign bodies.
Answer:
This is an example of directional selection.
Explanation:
Directional selection is a type of positive selection where the evolutionary fitness of one genotype is higher compared to the other ones, thereby favoring the selection of one particular phenotype and shifting allele frequencies towards the selected genotype. In a biological context, the directional selection increases the chances for surviving and for reproducing in those organisms that have the alleles favored by this type of selection. Thus, the directional selection produces the loss of genetic variability and leads to the fixation of the dominant alleles.
Answer:
Species of the genus Leishmania
Explanation:
The details of the research can be studied at : https://www.sciencemag.org/news/2009/09/mystery-desert