Answer:
it is the change in one or more genes
Lamprey and hagfish are jawless fish, with skeletons composed of cartilage. They do not have scales and are considered primitive fish. They are in the superclass cyclosystoma.
Answer: The means for transmission of disease-causing microorganism is provided by the direct or indirect contact.
Microorganisms can cause disease only once they are transferred to the body. The disease causing microorganisms are termed as pathogens which are transmitted by several ways such as from skin to skin, by nuclei droplets, through blood and body fluids or via air. In vector transmissions the disease is carried by the parasitic insects via animals, air borne transmission occurs when microorganisms move through air or the dust particles, droplet transmission occurs by coughing, sneezing or talking by the person who is infected while indirect transmission occurs by physical contact or by touching contaminated objects.