EmSAT Biology Flashcards

What is the function of white blood cells?

Answer: Defending the body against pathogens and infection

White blood cells (leukocytes) are part of the immune system. They defend against infections by identifying and destroying pathogens (bacteria, viruses) and foreign substances.

What is an antigen?

Answer: A substance that triggers an immune response

An antigen is any substance (usually a protein on the surface of a pathogen) that triggers an immune response. The immune system produces specific antibodies to neutralize antigens.

What is the role of antibodies?

Answer: To identify and neutralize specific antigens

Antibodies (immunoglobulins) are proteins produced by B cells that specifically bind to antigens, neutralizing pathogens or marking them for destruction by other immune cells.

How does vaccination work?

Answer: It introduces a weakened/inactivated pathogen to stimulate immune memory without causing disease

Vaccination introduces a weakened, inactivated, or partial pathogen (or its antigens) into the body, stimulating the immune system to produce antibodies and memory cells without causing the actual disease.

What is the difference between active and passive immunity?

Answer: Active immunity involves producing your own antibodies; passive immunity involves receiving ready-made antibodies

Active immunity involves your own immune system producing antibodies (from infection or vaccination) — it is long-lasting. Passive immunity involves receiving pre-made antibodies (e.g., from mother to baby) — it is temporary.

What is a pathogen?

Answer: A microorganism that causes disease

A pathogen is any microorganism or agent that causes disease. Pathogens include bacteria, viruses, fungi, protozoa, and prions.