B2

B2

MICROORGANISMS = bacteria, viruses and some fungiThey damage body cells

Some damage the cells DIRECTLYE.g. Malaria parasites invade the red blood cells and multiply, eventually causing the cells to burst open.Many produce poisons (toxins) that damage cells:. Some bacteria produce proteins that damage material holding cells togehter. This helps bacteria invade the body more deeply.E.g. staphylococcus bacteria cause food poisoning. Other microorganisms produce toxins that poison cells, causing fever of inflammation.

Microorganisms reproduce quickly inside the human bodyBacteria reproduce by making copies of themselves. To do this they need nutrients for energy and warm, moist conditions so the chemical reactions inside them can take place. There are many places like this inside the human body.E.g. IntestinesViruses need other cells to reproduce as they use parts of other cells to make copies of themselves.

Immune systemThe role of the immune system is to deal with infectious microorganisms entering the body. Immune responses always involve white blood cells. There are different types with different jobs.

Anything entering the body should be picked up straight away by a certain type of w/b/c

These w/b/c are able to detect things that are 'foreign' to the body  E.g. microorganismsThey engluf the microbes and digest them. They are non specific meaning they attack anything that's not meant to be there.

A different group of white blood cells attack SPECIFIFC microorganisms. These

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