Fever can support the immune system's attempt to gain advantage over infectious agents, such as viruses and bacteria, and it makes the body less favorable as a host for replicating viruses and bacteria, which are temperature sensitive. Infectious agents are not the only causes of fever, however.
Your sister's grandson is your great nephew. You are his great aunt (if you are a woman) or his great uncle (if you are a man).
The nephew then got an X from his mom that was a mix of her two Xâs. As you can see, there is some green, some blue and some orange. To make things easier to see, I have circled the part of the X that the uncle and nephew share: As you can see, they each shared the bottom right bit of their X chromosomes.