Describe the similar processes for how all organisms get oxygen from the environment to all of their cells.

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.

name and explain one of the event that occurs during meiosis that increases the variation in offspring even more than simple reproduction?