(d)+Pathogen+overview

(7) What is a pathogen? A pathogen is an organism or virus that causes a disease in any other organism. Common pathogens include bacteria, fungi and viruses.

(8) Draw up a table to show one example of a pathogen from each of the following group (virus, bacteria, fungi, protozoa, flat worms & round-worms).
 * = __**Group**__ = || = __**An Example of a Pathogen from the Group**__ = ||
 * == Virus == || Human Immunodeficiency Virus (HIV) - Causes AIDS. ||
 * == Bacteria == || Clostridium tetani (C. tetani) - Causes Tetanus which is an infection of the nervous system. ||
 * == Fungi == || Aspergillus fumigatus - Causes diseases in individuals with an immunodeficiency. ||
 * == Protozoa == || Giardia Lamblia - Causes giardiasis in the small intestine. ||
 * == Flat Worms == || Tapeworm - Lives in intestinal tracts of many species. ||
 * == Round-Worms == || Ascarsis - Infects the digestive tracts of humans and other mammals. ||

( (9) List the 6 key methods by which pathogens

1. Pathogens gain entry through: The anus is the last part of the digestive system and this can also let pathogens enter the body. This happens when contaminated objects are placed into the anus, or through sexual activity. Sexual activity can expose the vagina to sexually transmitted disease.
 * a. The skin **: healthy skin can act as a barrier to stop pathogens from entering the body. Cuts, scrapes and rashes leaves opening that can allow entrance of pathogens. Dirty needles or instruments that pierce through the skin can allow pathogens to enter the bloodstream.
 * b. Respiratory system **: some pathogens are airborne. The act of breathing can expose you to many different types of pathogens. This is why a healthy respiratory system will produce mucus in order to trap dust particles and pathogens that later excretes them.
 * c. the digestive system (mouth and anus): ** you must always be careful of what you put into your mouth. Food that has been lying on the ground or eating with dirty hands can be a way to let pathogens enter your body since the mouth is the first part of the digestive track.
 * d. The mucus membrane ( **nose and vagina): pathogens can enter the mucus membranes such as nose or vagina. Placing dirty fingers or objects inside the nose can bring in pathogens inside the body.
 * e. Eyes and ears **: they are both openings to the body which pathogens can enter.

2. Are transmitted: air, sexual intercourse, touching different surface

(10) Antibiotics (a) Where do antibiotics originate? (b) How do they work? (c) Why are the “human patient” cells not affected? (d) Explain why virus cells are not affected, and bacteria cells are.