Unit 22

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

Bacteria
Bacteria is a single celled organism, bacteria have evolved to thrive in almost any environment and can be found in almost any substance/surface and also in the human body, and only 1% of bacteria is actually harmful.
It's bad or infectious bacteria that cause illness as they rapidly reproduce and produce a toxin that kills or mutates cells, bacteria is also self-sufficient.

Viruses
A virus is a small capsule that contains DNA or RNA, viruses, unlike bacteria are not self-sufficient and need a host in order to reproduce I.E a human body.
When a virus enters the   body, it enters some certain cells and takes over making the now host cell make the parts the virus needs to reproduce, the cells are eventually destroyed through this process.
The most common viruses is the common cold, which has no cure.

Fungi
Mould, yeast and mushrooms are all types of Fungi.
Fungi live in the air, water, soil and on plants and   they can live in the body, usually without causing illness.
Some fungi have beneficial uses. For example, penicillin.
Fungi are also essential in making certain foods, such as bread and cheese.
Certain types of Fungi can cause illness such as Candida which is a yeast that can cause infections such as thrush.

Parasites
A parasite is a tiny organism that lives in or on a host (A body) which they use in order to feed. Parasites can cause severe illnesses, there are 3 main types of parasites: protozoa, helminths, and ectoparasites.

Protozoa- They are single celled organisms that can be free-living or parasitic in nature. They are able to multiply in humans, which contributes to their survival and also gives way to serious infections to develop.
Helminths- are large, multicellular organisms that are generally visible to the naked eye in their adult stages.
Like protozoa they can be either free-living or parasitic...