BIOL 1406 EXAM 4 Quiz 9

Which of these binds to receptor molecules on the host cell membrane? A B C D E

A

Which of these is reverse transcriptase? A B C D E

C

Which of these is the viral genome? A B C D E

E

What statements about viruses are true? -HIV contains two identical strands of DNA. -All viral genomes contain both DNA and RNA. -Enveloped viruses bud from the host cell. -HIV contains reverse transcriptase. -All RNA-containing viruses are retroviruses. -The capsid enters the host cell if the virus is enveloped. -A retrovirus contains RNA.

Enveloped viruses bud from the host cell. HIV contains reverse transcriptase. The capsid enters the host cell if the virus is enveloped. A retrovirus contains RNA.

What is the function of reverse transcriptase? -It catalyzes the formation of a polypeptide from an RNA template. -It catalyzes the formation of DNA from a polypeptide template. -It catalyzes the formation of RNA from a polypeptide template. -It catalyzes the formation of RNA from a DNA template. -It catalyzes the formation of DNA from an RNA template.

It catalyzes the formation of DNA from an RNA template.

Classify each phrase as applying to the lytic cycle, the lysogenic cycle, or both types of reproductive cycles of phages. -The cell reproduces normally -The cell is lysed (broken apart) -The host is destroyed -Viral genes are replicated -The viral DNA integrates into the chromosome of the host cell -New phages are assembled from viral DNA and proteins

LYTIC CYCLE The cell is lysed (broken open) New phages are assembled from viral DNA and proteins The host is destroyed LYSOGENIC CYCLE The cell reproduces normally The viral DNA integrates into the chromosome of the host cell BOTH CYCLES Viral genes are replicated

Sort the items according to whether they may be found only in free virus particles, only in uninfected host cells, or in both viruses and host cells: -DNA -Capsid -RNA -Ribosome -Envelope with glycoproteins -Protein -Capsomere (core protein)

VIRUSES ONLY: Capsid Capsomere (core protein) Envelope with glycoproteins HOST CELL ONLY: Ribosome BOTH: DNA RNA Protein

The pointer is indicating the virus's _____. envelope genome mitochondria capsid microfilaments

genome

What is the source of a viral envelope? host cell DNA prophages provirus host cell membrane viral glycoproteins

host cell membrane

Cycle A is the _____ cycle and cycle B is the _____ cycle. lytic ... lysogenic lytic ... phage lysogenic ... phage lysogenic ... lytic phage ... lysogenic

lytic ... lysogenic

Double-stranded viral DNA is incorporated into a host cell as a _____. promoter provirus transposon lac homeoboxes

provirus

What enzyme is responsible for the process seen here? RNA polymerase DNA polymerase reverse transcriptase endonuclease DNA ligase

reverse transcriptase

The lytic cycle of bacteriophase infection ends with the ____. -replication of viral DNA entry of the phage protein coat into the host cell -assembly of viral particles into phages -the injection of phage DNA into a bacterium -rupture of the bacterium

rupture of the bacterium

The genetic material of HIV consists of _____. single-stranded DNA single-stranded RNA double-stranded DNA double-stranded RNA none of the above

single-stranded RNA

As a result of the lytic cycle, _____. the host cell is not destroyed the host cell's DNA is destroyed viral ribosomes are produced viral DNA is incorporated into host cell DNA a prophage is created

the host cell's DNA is destroyed

Viral DNA makes mRNA by the process of _____. replication infection translation lysis transcription

transcription

In the lysogenic cycle _____. -host DNA is destroyed and viral DNA is replicated -a bacterium replicates without passing viral DNA to its daughter cells -viral DNA is destroyed and host DNA is replicated -a bacterium divides once before the lytic cycle is initiated -viral DNA is replicated along with host DNA

viral DNA is replicated along with host DNA

The pointer is indicating the ____. viral envelope viral nucleic acid genome bacterium's nucleic acid genome viral protein coat bacterium's plasma membrane

viral protein coat