Unit 12: Diseases and Infection
Btec Assignment
Aim A: Investigating different types of diseases and
infections that can affect humans
,P1) Explain the characteristics of the five main types of pathogens and a disease caused by each.
The following three slides contain each of the five main types of pathogens and their description, disease
caused by each, how they affect humans and their life cycle.
Name of Description Disease they cause
pathogen
Bacteria Single celled organisms without Pneumonia - when the bacteria (Streptococcus pneumoniae) invade
a nucleus (prokaryotic) your body and multiply in your lungs, they destroy and attack organs.
Parasite Living organisms that can live Tapeworm infection - once the tapeworm is inside your body, it attaches
inside the bloodstream and to the inner wall of the intestines and feeds off the food being digested,
require a host which can then cause digestive problems.
Viruses Non-living particles that can Chicken pox - a highly contagious disease caused by the
only reproduce within a living varicella-zoster virus (VZV) which affects the skin on the entire body and
cell (akaryotic) can cause itchy, blister-like rashes.
Fungus Simple organisms that grow as Athlete's foot - caused by dermatophytes and when the environment
single cells (eukaryotic) they live in gets warm and moist, they grow out of control and start to
cause symptoms.
Protozoa Single celled organisms with a Malaria - caused by the Plasmodium species which mature in
nucleus (eukaryotic) blood-feeding insect hosts before injecting parasites into vertebrate hosts
during a blood meal.
, Name of How it affects humans (causes disease)
pathogen
Bacteria e.g. Bacteria produce and secrete toxins that can cause damage to other cells and organisms. The rapid
Streptococcus production of bacterial protein occurs at the ribosomes and these toxins then move to the surface to
pneumoniae be secreted to cause cell damage in the body.
Parasite e.g. Parasites mostly reside in the intestines and this is where most of the damage occurs. Ectoparasite
tapeworm and endoparasite are two types of parasites; endoparasites live inside an organism and
ectoparasites live on the surface.
Viruses e.g. Viruses can take over host cell metabolism to reproduce themselves. The virus enters the cell and
varicella-zoster goes to the nucleus to insert its own genetic material to replicate itself. The new viruses then burst
virus out of the cells damaging them and spreading to healthy tissue.
Fungus e.g. When fungal organisms enter the body they grow, spread and invade into tissue. Some fungi can
dermatophytes invade the blood vessels and cause infection in the bloodstream and organs. Ectoparasitic fungi
grow on the body surfaces, such as in termites.
Protozoa e.g. Protozoa release toxic which can damage and infect cells. The infection results in tissue damage
Plasmodium leading to disease. In chronic infections the tissue damage is often due to an immune response to
the parasite
Btec Assignment
Aim A: Investigating different types of diseases and
infections that can affect humans
,P1) Explain the characteristics of the five main types of pathogens and a disease caused by each.
The following three slides contain each of the five main types of pathogens and their description, disease
caused by each, how they affect humans and their life cycle.
Name of Description Disease they cause
pathogen
Bacteria Single celled organisms without Pneumonia - when the bacteria (Streptococcus pneumoniae) invade
a nucleus (prokaryotic) your body and multiply in your lungs, they destroy and attack organs.
Parasite Living organisms that can live Tapeworm infection - once the tapeworm is inside your body, it attaches
inside the bloodstream and to the inner wall of the intestines and feeds off the food being digested,
require a host which can then cause digestive problems.
Viruses Non-living particles that can Chicken pox - a highly contagious disease caused by the
only reproduce within a living varicella-zoster virus (VZV) which affects the skin on the entire body and
cell (akaryotic) can cause itchy, blister-like rashes.
Fungus Simple organisms that grow as Athlete's foot - caused by dermatophytes and when the environment
single cells (eukaryotic) they live in gets warm and moist, they grow out of control and start to
cause symptoms.
Protozoa Single celled organisms with a Malaria - caused by the Plasmodium species which mature in
nucleus (eukaryotic) blood-feeding insect hosts before injecting parasites into vertebrate hosts
during a blood meal.
, Name of How it affects humans (causes disease)
pathogen
Bacteria e.g. Bacteria produce and secrete toxins that can cause damage to other cells and organisms. The rapid
Streptococcus production of bacterial protein occurs at the ribosomes and these toxins then move to the surface to
pneumoniae be secreted to cause cell damage in the body.
Parasite e.g. Parasites mostly reside in the intestines and this is where most of the damage occurs. Ectoparasite
tapeworm and endoparasite are two types of parasites; endoparasites live inside an organism and
ectoparasites live on the surface.
Viruses e.g. Viruses can take over host cell metabolism to reproduce themselves. The virus enters the cell and
varicella-zoster goes to the nucleus to insert its own genetic material to replicate itself. The new viruses then burst
virus out of the cells damaging them and spreading to healthy tissue.
Fungus e.g. When fungal organisms enter the body they grow, spread and invade into tissue. Some fungi can
dermatophytes invade the blood vessels and cause infection in the bloodstream and organs. Ectoparasitic fungi
grow on the body surfaces, such as in termites.
Protozoa e.g. Protozoa release toxic which can damage and infect cells. The infection results in tissue damage
Plasmodium leading to disease. In chronic infections the tissue damage is often due to an immune response to
the parasite
