Relate locard's principle of exchange to trace fiber evidence.

Person to person contact, person to item contact, direct transfer and secondary transfer

Explanation:

a. by using fur or clothes to trap heat energy near the body

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.