Introduction to the immune system

Define the term antigen.

Answer explanation

An antigen is a substance that triggers an immune response, often recognized as foreign by the body. It can be a protein, polysaccharide, or other molecules that provoke the production of antibodies.

State the different physical barriers in the body of animals.

Choose any options that are part of the chemical barriers.

• sebum

• tears

• sneezing

• HCl

• skin

List at least 2 signs of inflammation.

Answer explanation

Two common signs of inflammation are redness and swelling. Redness occurs due to increased blood flow, while swelling results from fluid accumulation in tissues.

What is the difference between the primary and secondary response?

Answer explanation

The primary response is the initial immune reaction to a pathogen, while the secondary response is a faster and stronger reaction upon subsequent exposures, due to memory cells formed during the primary response.

The lines of defenses in the body are 2

• True

• False

State the three lines of defence in the animal body.

What makes the skin impenetrable to pathogens/forgein bodies?

• Collagen

• Sebum

• Keratin

• Chitin