A(n) mutation occurs when a base or sequence is doubled and
inserted in the sequence.

substitution
deletion
duplication
inversion
ASAP

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.

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.