Week 4 - Quiz 3
which statement describes a virulent phage?
A virulent phage destroys bacteria.
True or False: A characteristic that is independently acquired by reversal or convergent evolution exhibits homology.
False
What is a prophage?
It is phage DNA that is integrated into bacterial DNA.
How do retroviruses differ from other RNA viruses?
Retroviruses have reverse transcriptase instead of RNA-dependent RNA polymerase
At what stage of a lytic infection are phage components put together to make new viruses?
assembly
what is the protein coat of a virus called?
capsid
The bacterium that causes botulism disease is harmless until it:
contains a certain prophage DNA
A taxon that includes all the descendants of an ancestor is called:
monophyletic
The organism labeled B in the accompanying figure (phylogenetic tree) is a common ancestor to:
organisms 2,3,4,5 and 6
A taxon that diverges earlier than the other taxa being considered in cladistic analysis is a(n):
outgroup
In the accompanying figure (phylogenetic tree), the taxon labeled II is:
paraphyletic
When faced with multiple possible cladograms, the criteria of ____ can be employed to pick the "best" hypothesis.
parsimony
What are the viruses that attack bacteria?
phages
The specificity of viruses to different types of cells is due to ____ sites on the host cell.
receptor
In the accompanying figure (phylogenetic tree) , the pair of organisms that have the most recent ancestor is:
2 and 3
True or False: Membership in a clade cannot be established by shared ancestral traits alone.
True
Which characteristic defines a virus?
Viruses cannot metabolize.
Which statement describes a temperate virus?
a temperate virus does not always destroy its host
At what stage of the lysogenic cycle would a prophage appear?
integration
What type of conversion occurs when a bacterium carrying viral genes takes on new, atypical characteristics?
lysogenic