In humans, the placenta is essential to the embryo for RESPIRATION, NUTRITION AND EXCRETION.
The placenta refers to an organ in the uterus of pregnant mammals that is responsible for nourishing and maintaining the unborn baby through the umbilical cord. Th placenta has many functions but primarily it plays critical roles in the nutrition, respiration and excretion of the fetus. Its other functions include: production of hormones, production of immunity for the fetus for prevention from infections, etc. <span />
Aristotle classification
He classified plant and animals into two separate kingdoms
Modern Classification
In this system also, there were two separate kingdoms for plant and animals
<span>The period of growth in between cell divisions is called . The cell cycle is the series of phases a cell goes through as it grows and divides. The division of the cell nucleus during the M phase of the cell cycle is called . During the G1 phase cells mostly grow.</span>
