test study thingy micro

Pick your favorite of the helminths we discussed and describe what phylum it is in, how it is acquired, and what symptoms it causes. (3 points)

tape worm (phylum)
undercooked meat
weight lost

What is an enveloped virus?

A virus that has a lipid (fat) envelope surrounding its capsid, which helps it enter host cells

There are viruses with one strand of DNA and one strand of RNA in the same virus. (TRUE/FALSE)

False

What is meant by “host range” and what determines the host range of a virus?

the types of cells a virus can infect
specific receptors on host cells and the virus’s ability to attach

Why are viruses not considered living? Give two reasons.

Cannot reproduce independently
Cannot carry out metabolism or produce ATP

Please give two major roles of fungi.

Decomposers
Symbiotic relationships (help plants, etc.

How do you define a eukaryotic species? Why does that definition pose challenges when considering prokaryotic species?

Eukaryotic species: organisms that can reproduce sexually and produce fertile offspring

Problem: prokaryotes do not reproduce sexually, so this definition does not apply

The virus that causes shingles is best described as persistent. (TRUE/FALSE)

true

In terms of structure, how are viroids different from viruses?

• Viroids are smaller and made only of RNA

• They do not code for proteins

What is the major structural difference between the normal form of the protein and the prion form?

• They have the same amino acids but different folding (shape)

• Prions are misfolded proteins that cause disease

What are the 5 major steps of viral infection in any kind of cell? Where do infections with animal viruses differ from phage infection?

• Attachment

• Entry

• Uncoating

• Replication and synthesis

• Assembly and release
  difference
  Animal viruses enter the whole cell (endocytosis or fusion)
  Phages inject only their DNA into bacteria

Describe (or draw) the lysogenic cycle of a temperate phage.

• Viral DNA integrates into host DNA (prophage)

• Remains inactive (latent)

• Replicates with host cell

• Can later switch to lytic cycle and destroy the cell

Give an example of an oncogenic virus. How can a virus cause cancer?

HPV (Human papillomavirus)
insert its DNA into the host genome, disrupting normal cell cycle control