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.
Eight weeks of age has long been accepted as the optimal time to acquire a new pup. By eight weeks, sufficient dog-dog socialization has taken place with mother and litter mates to tide the puppy over until he is old enough to safely meet and play with other dogs in puppy class and dog parks.