Specialized cells are made to perform a specific task that no other cell does. Like skin cells. They are made for protecting the inside of our body from harmful items outside. Or blood cells, made for transporting oxygen and air to other parts of our body, and carrying carbon dioxide out.
Genetic drift is changes in allele frequencies of a gene pool due to chance or random events. This can occur in large or small populations. Genetic drift causes gene pools of two isolated populations to become dissimilar as some alleles are lost and other are fixed.
For the answer to the question above, <span>The only taxon in which the biological characteristics are clearly identifiable is the <em><u>"species".</u></em></span>