LearnSmart 13.5

which of the following viral release methods may not initially destroy the cell? a. lysis b. apoptosis c. budding

c

reassortment of gene segments that encode viral surface proteins that are recognized by the immune system can result in a loss of the immune system's ability to recognize and respond to the virus. This phenomenon is called antigenic

shift

True or false: viral particles can be shed from a host in feces, urine, genital secretion, blood or mucus, and saliva released from the respiratory tract during coughing or sneezing, allowing transmission to new host

true

reverse transcriptase is a(n) ____ polymerase a. RNA-dependent RNA b. DNA-dependent RNA c. DNA-dependent DNA d. RNA-dependent DNA

d

most animal DNA viruses will replicate with the host cell's what?

nucelus

HIV is described as a ___ because it uses reverse transcriptase to make a DNA copy from its RNA genome

retrovirus

after a virus enters the cell, the nucleic acid spears from the protein coat, a process called ____

uncoating

true or false: enveloped viruses enter the host cell by endocytosis only, while non-enveloped viruses can enter the host cell by fusion or endocytosis

false

the virally encoded polymerase needed for the replication of RNA viruses is called a a. topoisomerase b. ribonuclease c. replicase d. primase

c

match the genome of each type of RNA with its description of function a. (+) strand genome b. (-) strand genome c. double-stranded genome 1. consists of both a (+) and (-) strand 2. is the complement to mRNA 3. serves as mRNA

c1, b3, a2

Enveloped viruses derive their envelopes from: a. the environment b. the host matrix protein c. certain host organelles d. the host cytoplasmic membrane

c,d

in single-stranded (-) RNA viruses, the enzyme replicas is important because it uses (-) RNA: a. to make more (-) RNA to be packaged into newly assembled viral particles b. as a template to make (+) DNA which integrates in the host genome c. as. a template to make (+) RNA, which can be used for protein synthesis

c

in the case of retroviruses, reverse transcriptase uses a viral RNA template to synthesize RNA, which can then be: a. transported to the cytoplasmic membrane for export to neighboring cells b. translated directly to form multiple new viruses c. integrated into a host cell chromosome where it remains latent d. transcribed and translated to form new virons

c, d

in double-stranded RNA viruses, the viral replicase uses the ___ strand of RNA to make ____ strands of RNA that can then be translated.

(-), (+)

In single strand (+) RNA viruses a. the virals genome functions as mRNA and is translated b. the viral RNA functions as a ribozyme for protein synthesis c. (-) RNA replicase is synthesized from the (+) RNA template

a

Replicases are ___ polymerases a. RNA-dependent RNA b. RNA-dependent DNA c. DNA-dependent RNA d. DNA-dependent DNA

a

enveloped viruses exit host cells by ___; non-developed viruses are released upon ___ of the host cell

budding, apoptosis

a non-enveloped virus can gain entry into animal cells via a. injection of viral nucleic acid across the cell membrane b. fusion of the viral envelope and the cell membrane c. endocytosis of the virus by the host cell

c

list the steps of an animal virus infection cycle in the correct order: 1. penetration and uncoating 2. assembly 3. release 4. synthesis of viral proteins and replication of the genome 5. attachment

5, 1, 4, 2, 3

When two different strains of a segmented virus enter the same cell, reassortment of the gene segments can occur, resulting in what? a. antigenic shift b. slip c. evasion d. antigenic drift

a

enveloped viruses can derive their envelopes from a. certain host organelles b. the host matrix protein c. the host cytoplasmic membrane d. the environment

a, c

the replication strategy of viruses can be divided into three general categories: those used by: a. DNA viruses b. enveloped viruses c. reverse transcribing viruses d. RNA viruses

a, c, d

In RNA viruses that have a single (+) RNA genome, the viral genome a. is used as a template to make complementary (-) RNA strands that act as templates to produce more (+) RNA strands b. is reverse transcribed into RNA c. serves as a template for the synthesis of more (+) strand RNA d. can be translated to make proteins

a, d

in order to infect an animal cell, viruses must a. inject their RNA through the host cell membrane b. attach to receptors on the host cell cytoplasmic membrane c. modify host cell receptors into glycoproteins d. inject their DNA through the host cell membrane

b

Replication of single-stranded DNA viruses is quite similar to that of double-stranded DNA viruses, except that ___. a. the single-stranded DNA molecule must be reverse transcribed into cDNA b. a complement to the single-stranded DNA molecule must be synthesized c. a copy of RNA must be synthesized of double-stranded DNA d. the single-staged DNA forms hairpin loops, making a complementary strand unnecessary

b

the enzyme of RNA viruses that lacks proofreading ability and thus makes many mistakes compared to the polymerases of DNA viruses is: a. DNA-depended RNA polymerase b. replicase c. transductase d. DNA polymerase

b

the protein receptor molecules on a host cell to which viruses attach by their spikes are typically ____. a. phosphates b. glycoproteins c. phospholipids d. glycogens

b

Identify all the methods by which an enveloped virus can gain entry into animal cells a. injection of viral nucleic acids across the cell membrane b. fusion of the viral envelopes and the cell membrane c. endocytosis of the virus by the host cell

b, c

all of the following are required for synthesis of new virus particles in a host cell EXCEPT ___. a. RNA synthesis b. protein synthesis c. genome replication d. homologous recombination

d

which of the following describes the various viral parts coming together to produce irons? a. release b. penetration c. absorption d. assembly

d