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.
At 12 weeks of age, your puppy's focus is still to eat, drink, sleep, eliminate and play. Your puppy should be underway to learning right from wrong and in the process of being housebroken. He should be playful and curious. You need to make sure your home is puppy proof and safe.