Answer:
Exercise and eat well balanced diets
The endocrine system is one the system in the human body that regulates all the hormones which aids in the normal functioning of the other systems. Therefore, the major functions of the endocrine system include metabolism, and puberty body. Hope this answers your question.
Crossing over or recombination, creates new combinations of genes in the gametes that aren’t found in either of the parents
I think it should be required. You need to make sure that the baby developing inside of you is healthy and growing correctly. You also need these tests to ensure the moms safety during the pregnancy. And no i don’t think you should have to cover the cost.