Mutations and variations are
1:willed into existence
2:random

2:random

Explanation:

Mutations are RANDOMLY caused by mistakes in the DNA replication process there is no telling when they will happen, nor is there a way to force mutations!

If correct PLEASE give brainliest and a thanks! But you do not have to!

Thanks,

andrewschneider05

because of

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.