What are organisms that are so small that they can only be seen through a microscope?

What is a combination of body defenses made up of cells, tissues, and organs that fight pathogens in the body?

What is the secondary circulatory system that helps the body fight pathogens and maintain its fluid balance?

What is a preparation of dead or weakened pathogens that is introduced into the body to cause an immune response?

What are the substances that send the immune system into action?

What is any condition that interferes with the normal or proper functioning of the body or mind?

What is a disease that can be spread to a person from another person, an animal, or an object?

What are simple one-celled organisms?

What are specific proteins that attach to antigens, keeping them from harming the body?

What is the body’s response to injury or disease, resulting in a condition of swelling, pain, heat, and redness?

What is the ability to resist the pathogens that cause a particular disease?

What are germs that cause diseases?

What is a condition that happens when pathogens enter the body, multiply, and cause harm?

What are the special white blood cells in the blood and lymphatic system?