The reason why taq polymerase is used is because it is thermostable, meaning that it can remain intact and reactive after being exposed to the cycles of high temperatures that are used in PCR (an upwards of 94 degrees Celsius). If human DNA polymerase were used instead, it would immediately unfold and become inactive after the first round of high temperatures, effectively ceasing the PCR.
No, they don't have organs and organ system.
Cells form tissues, Tissues form organs, Organs forms organ system; Unicellular have their own one cell only. So, it can't possible that they have organs or organ system.
C.) Feedback inhibition slows down cellular respiration (to conserve resources)
Hope I helped
A haploid cell has half the total number of chromosomes, so the animal, which has mostly diploid cells, would have 16 chromosomes.