I’m not entirely sure about what you’re asking but chargaff’s rule is the thing that states that the amount of each “letter” in DNA is equal to its pair. Guanine (g) pairs with cytosine (C) and the same with adenine(A) and thymine (T). I’m sorry my answer is so vague, but I hope it helps a little!
The major function of the immune system is to protect the host from environmental agents such as microbes or chemicals, thereby preserving the integrity of the body. This is done by the recognition of self and response to non-self.
I believe that its meiosis but I could be wrong.
Skin is the Largest barrier agaisnt Pathogens which include Bacteria which cause infections.
Homo sapiens means wise human being, it one of several species grouped into the genus Homo, but it is the only one that is not extinct. It is the specie where all human beings belong. They replaced Neanderthals during 30,000 BC. Scientists believe that Homo sapiens appeared in Africa between 150,000 and 200,000 years ago.