The cells of the innate system recognize and respond to pathogens in a generic way, but, unlike the adaptive immune system (which is found only in vertebrates), it does not confer long-lasting or protective immunity to the host.ll white blood cells (WBC) are known as leukocytes. Leukocytes are different from other cells of the body in that they are not tightly associated with a particular organ or tissue; thus, they function similar to independent, single-cell organisms.
Ideally, the age to bring home a puppy is when heâs between seven and twelve weeks old. This is considered the critical socialization period in a puppyâs life, the time when he learns the most about his environment and begins to adjust to his surroundings.
Approximately twenty five states have laws or administrative regulations that state how old a puppy must be before it is offered for sale or adopted out to an owner. Of those states with laws, all but three require that a puppy be at least eight weeks old before being offered for sale. Maine, Virginia, and Wisconsin mandate that a puppy be at least seven weeks old.