Learn Smart 13.1 - 13.4

the ___ or maturation state of the T4 phage lytic cycle is marked by the formation of the new phage particles inside of the host cell

assembly

A viral capsid is made up of subunits called a. nuelocapsids b. capsomeres c. proteins d. amino acids e. facets

b

specialized transduction a. results from errors in phage head packing b. transfers only phage DNA c. results from errors in excision of the prophage d. produces defective phage particles e. transfers phage DNA and adjacent host genes

c, d, e

Which of the following statements about virus nucleic acid is true? a. all viruses contain protein and RNA b. all viruses contain protein and DNA c. viruses contain both DNA and RNA d. Viruses contain either DNA or RNA

d

this image shows a __ virus (cylindrical with nucleic acid inside)

helical

the term ___ is used to describe the future or bursting of a cell

lyse

___ phages have the option of entering the prophage stage, while __ phages always burst the host cell shortly after infection

lysogenic, lytic

lysogen are protected against infection by the same phage because the phage-encoded repressor protein binds to the ___ on the incoming phage, preventing expression of the phage genes

operator

to maintain the lsyogenic state, a ___ protein prevents expression of the gene required for excision

repressor

___ transition is the result of exclusion errors made as temperate phages transition from a lysogenic to lytic cycle

specialized

viral proteins that stick out form the viral envelope or capsid and attach to host cell receptors are termed ___

spikes

Phage heads that contain only bacterial DNA are called generalized ___ particles

transducing

true or false: some lysogenic phages can increase the pathogenicity of bacterial host

true

in enveloped viruses, sandwiched between the nucelocapsid and the envelope is the ___. a. matrix protein c. nucleocapsid d. endocapsid e. exocapsid f. exoskeleton

a

the binding of a bacteriophage surface protein to a host cell receptor is called: a. attachment b. assembly c. entry d. release e. synthesis f. fixation

a

this image shows the ___ stage of the T4 phage lytic cycle (phage squatting down and secreting its genome) a. genome entry b. assembly c. synthesis d. release e. attachment

a

virus infections that result in the formation of new virus particles are described as ____. a. productive b. primary c. lateral d. horizontal e. latent

a

what are the two types of transduction? a. specialized b. generalized c. primary e. specific f. adaptive g. secondary

a, b

replication of temperate phages and lytic phages have which of the following in common? a. attachment b. assembly c. integration of the viral genome d. release e. genome entry f. biosynthesis of viral components

a, b, c, d, e, f

viruses are challenging to study because: a. they are obligate intracellular parasites b. they can only be seen using a light microscope c. they can only be seen using an electron microscope d. they are composed of nucleic acid and protein

a, c

the number of phage particles released from a host cell is called the ___ size

burst

match each possible outcome of phage replication with the correct definition: a. productive infection b. latent state 1. viral genome remains silent with the cell 2. new viral particles are produced

a2, b1

___ is a change in the phenotype of lysogen as a consequence of the specific prophage it carries. a. latency conversion b. lysogenic conversion c. lysogenic cycle

b

the arboviruses are a group of unrelated viruses grouped together for which of the following reasons? a. they only infect primates b. they are spread by arthropods c. they only infect archaea d. they are spread by airborne areoles

b

which of the following about classifying viruses is FALSE? a. viruses can be classified based on different viral characteristics b. it is not as important as classifying organisms since they are not living entities c. an online database classifying viruses is kept by the ICTV (International Committee of Taxonomy of Viruses) d. it provides a useful way to identify and study viruses

b

rank the following by size, from smallest to largest, starting with the smallest at the top a. bacteria b. viruses c. human cells

b, a, c

consequences of lysogeny include a. morphological changes b. immunity to superinfection c. phage induction and conversion d. lysogenic conversion

b, d

the study of viruses is important because a. viruses can be a vehicle for horizontal gene transfer in bacteria b. viruses cause all known human diseases c. bacteriophages play a significant ecological role in reducing bacterial populations in nature d. viruses play a role in bacterial conjugation f. there are many medically important viruses that cause disease

a, c, e

viruses that infect bacteria are called a. bacteriophages b. prions c. plasmids d. phages e. viroids

a, d

which facts best support the position that viruses are not living organisms? a. viruses are inert outside of a host b. viruses are agents of disease c. viruses are not prokaryotic d. viruses cannot reproduce on their own e. verses are very small

a, d

late proteins of the T4 lytic cycle include: a. T4 tail fibers b. T4 chromosome c. viral envelope d. nuclease to digest the host DNA e. T4 capsomere components

a, e