What effect does the gradual decrease in ph from 13 to 1 have on the action of amylase

: A decrease in pH is too acidic compared to optimum pH for amylase activity.

i'd say that the moon rock is about 2.2 billion years old.

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.