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Unit 12A: diseases and infection
Section A: infectious diseases
In this assignment I will discuss both infectious and non-infectious diseases, and describe a
case study of two specific diseases. This consists of assessing the physiological effects of the
diseases and the abnormality that they cause to a person’s structure or function. An
infectious disease is a transmissible disease which can be caught from person to person,
which is caused by organisms such as bacteria, viruses, fungi or parasites (PCI 2019).
Microorganisms like these are known as pathogens. However, a non-infectious disease is a
disease which cannot be transmissible from person to person examples of these are
genetics, diets and environmental factors.
Infectious diseases
An infectious disease is caused by bacteria, fungi or parasites, they are caused by
microorganisms and can spread between individuals. Microorganisms that because diseases
are called pathogens. Pathogens disrupt the body’s normal processes which causes disease.
Pathogens: (printablediagram,2019)
Bacteria:
Main features: bacteria are prokaryotic cells that
do not have organelles or a true nucleus, they
are single-celled microorganisms. Bacteria with a
capital B refer to domain bacteria one of three
domains of life, which are also single-celled
organisms. They lack organelles such as,
chloroplasts and mitochondria, they do not have
a true nucleus unlike eukaryotic cells, instead
their DNA consisting of a double strand which is
continuous and circular, located within a
nucleoid, which is an irregularly shaped region
that does not have a nuclear membrane.
Bacteria have both a cell membrane and cell wall made of peptidoglycan, a molecule of
sugar and amino acids. (biologydictionary,2019)
How to tell is an organism is a bacteria: the single celled organisms cell structure is simpler
than any other organism, as they don’t have a nucleus or membrane bound organelles.
Their control centre containing genetic information is contained in a single loop of DNA
(microbiologysociety,2019). Many types of bacteria have extra cell structures which help
them with survival, most have a flagellum which are tail-like structures that allow the
bacteria to move through liquids. They also have a slime capsule around the cell wall
protecting the bacterium and to stop it from drying out (bbcbitesize,2019)