Unit 2-Parasitism Flashcards
What are the six common parasitic groups?
Protists
Nematodes
Arthopods
Viruses
Platyhelminthes
Bacteria
What is a relatively inefficent mechanism of transmission?
Direct Contact
Give examples of two key parasites with intermediate hosts
Schistomosoma
Plasmodium
How are endoparasites of body cavities transmitted?
Direct Contact
Consumption of Intermediate Host
How are ectoparasites transmistted?
Direct Contact
Give an example of an endoparasite of the body cavity
Tapeworm
Give an example of an endoparasite of the body tissue
Plasmodium
How are endoparasites of the body tissue transmitted?
Vectors
What is HIV caused by?
A virus
Define a virus
Infectious agents that can only replicate inside in a host cell
Describe what is in the structure of a virus
Antigens on the surface
Nucleic Acid (RNA/DNA)
Protein Capsid
Outer Envelope
What is a protein capside?
Protective protein coat surrounding the nucleic acid
What are the two types of nucleic acids found in viruses?
RNA and DNA
Why are viruses not classed as living?
Do not carry out any of the normal functions for life except for reproduction, which they can only do in the cell of living organisms
Describe the stages in virus reproduction
- Virus antigens to host cell surface
- Virus DNA inserted into host cell
- Virus DNA is replicated by host enzymes
- Virus genes are transcribed to RNA which is translated to make viral protein coats
- New virus particles are assembled and burst out of the host cell
Give examples of DNA viruses
Chickenpox
Herpes
Small pox
Give examples of RNA viruses
Influenza
Hepatitis
Ebola
What differs in RNA viruses replication?
Viral RNA genome is replicated directly using an enzyme from the virus
Give an example of RNA retroviruses
HIV
How do RNA retroviruses replicate?
Use the enzyme reverse transcriptase to form a DNA copy of the virus genome. When virus is reproducing, the DNA copy of the genome will be transcribed to RNA which is then translated to make new viral proteins.