What indicates the biological sex of each individual on the pedigree?

the shape of the symbol

Explanation:

See the picture attached. In family pedigrees, the shape of the symbols represent biological sex. The circles represent females and squares represent males.

The individuals with the trait or disease usually have their symbol shaded. So an affected female would have a shaded circle, and an unaffected male would have a white square.

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.