Causes and Spread of Infection

1.1 Identify the differences between bacteria, viruses, fungi and parasites.

Bacteria are single-celled living organisms that can neither be classified as animals nor plants. Although each one just about the size of a single cell, due to their rapid reproduction, it is not uncommon to find massive amounts of them in a small sample. Bacteria are identified as prokaryotes which are unicellular organisms that lack a nucleus.

Viruses, in contrast to bacteria, are non-living entities made from RNA or DNA which are basically complex molecules that mostly carry genetic information. These genes are shielded from damage by a protein sheath, and some even have a shield of fat that serves as a form of protection while they are residing outside of a living cell. Viruses are not usually able to carry out their activities outside of a living cell.

Fungi, when compared to bacteria and viruses, are a bit more complex. They are living organisms classified as eukaryotes which are multicellular organisms like animals and plants. However, unlike other eukaryotic organisms, the cell wall of fungi is made up of chitin, a material found in exoskeletons of organisms such as insects.

Parasites are organism that parasitizes its host by feeding off of it or residing within. Parasites come in different forms and may exist as bacteria, fungi, animals, plants, and so on. The term “parasite” refers to any organism that lives on or inside a “host” and derives its sustenance from the host. Unlike bacteria which may be beneficial, illness in human beings is the only one way that parasites may directly affect us as humans.

Other answers in the full document:

• 1.2 Identify common illnesses and infections caused by bacteria, viruses, fungi and parasites.
• 1.3 Describe what is meant by infection and colonisation.
• 1.4 Explain what is meant by systemic infection and localised infection.
• 1.5 Identify poor practices that may lead to the spread of infection
• 1.6 Identify how an understanding of poor practices can be applied to own professional practice.
• 2.1 Explain the conditions needed for the growth of microorganisms.
• 2.2 Explain the ways an infective agent might enter the body.
• 2.3 Identify common sources of infection.
• 2.4 Explain how infective agents can be transmitted to a person.
• 2.5 Identify the key factors that will make it more likely that infection will occur.
• 2.6 Discuss the role of a national public health body in communicable disease outbreaks.