Answer:
At the beginning of the follicular phase, the lining of the uterus (endometrium) is thick with fluids and nutrients designed to nourish an embryo. If no egg has been fertilized, estrogen and progesterone levels are low. As a result, the top layers of the endometrium are shed, and menstrual bleeding occurs.
More advanced than tools used on earth
Answer:
<em>The gene that causes hemophilia is passed from parent to child. A mother that carries the gene is called a carrier, and she has a 50% chance of having a son with hemophilia and a 50% chance of having a daughter who is also a carrier.</em>
Explanation:
The answer is: Chloroplasts.