Bacteria are often helpful because they​

Yes it is helpful

Explanation:

Not only do we live in harmony with these beneficial bacteria, but they are actually essential to our survival. Good bacteria help our bodies digest food and absorb nutrients, and they produce several vitamins in the intestinal tract — including folic acid, niacin, and vitamins B6 and B12.

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.