In humans, the yolk sac is the
site of origin for blood cells and primordial germ cells. The human yolk sac is
a membrane located outside the embryo and it is connected by a tube through the
umbilical opening to the embryo's midgut. The yolk sac serves as an early site
for the formation of blood and in time, is incorporated into the primitive gut
of the embryo.
Observation is broken up into three parts. The first is the date. Then you have the activity and last you have a brief description of what is being observed.
When Mufasa took over, because the hyenas were introduced
Natural gas made due to pressure and under buried layers of rock over millions of years ago
