40 points
in order for a cell in culture to get rid of wastes the concentration of waste must be
a) higher in the medium than the cell cytoplasm
b) lower in the medium than the cell cytoplasm
c) higher than the concentration of water
d) lower than the concentration of oxygen

The answer is higher than the concentration of water. :)

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.