4. Endometriosis and polycystic ovary syndrome. Endometriosis is when the tissue that normally lines the uterus grows outside the uterus. Polycystic ovary syndrome is a hormonal disorder causing enlarged ovaries with small cysts on the outer edges.
5. Fraternal and identical twins. Identical is when two different eggs are fertilized. Fraternal is when one egg is fertilized and splits into two babies.
6. Two influences on teen sexual behavior are peer pressure and social media. Social media influences it naturally by using self consciousness and peer pressure makes people feel forced to do something.