The reproductive system in both males and females are controlled and regulated by the interaction of hormones from the hypothalamus and pituitary glands with hormones from the reproductive organs. How do these hormones affect the development of male and female reproductive systems
Think of it this way:
DNA inside cells store all the genetic information on a person's looks, eye colour, hair colour etc. It makes them unique. The analogy of being like books in a library basically suggests that in a library there is so much information and every book is different with different knowledge... That's basically what DNA is; millions of different information things.
Answer:
Mice and rats make up approximately 95% of all laboratory animals, with mice the most commonly used animal in biomedical research.