Mer Scott
Test por , creado hace más de 1 año

Objectives: describe the basic structural characteristics of viruses, compare the lytic and lysogenic replication cycles of bacteriophages, outline the replication cycles of mammalian cell viruses(naked and enveloped), describe the term viral latency in relation to the replication of bacterial and mammalian viruses.

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Mer Scott
Creado por Mer Scott hace alrededor de 7 años
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L5 Structure and Function of viruses

Pregunta 1 de 13

1

Which statement about viruses is NOT correct?

Selecciona una de las siguientes respuestas posibles:

  • Viruses can multiply only by using a dividing host cell's machinery.

  • Viruses are ubiquitous.

  • Virus particles are called virions.

  • There is estimated to be around 2000 viruses which affect humans.

Explicación

Pregunta 2 de 13

1

Which statements BEST describes viruses?

Selecciona una o más de las siguientes respuestas posibles:

  • Viruses are a diverse group of acellular or 'sub-cellular' particles with no metabolic activity of their own, which rely on the biomachinery of their hosts to reproduce.

  • Viruses are very small non-living cells which hijack living cells in order to reproduce copies of themselves.

  • Viruses are ubiquitous 'sub-cellular' particles which rely on their hosts to reproduce.

Explicación

Pregunta 3 de 13

1

The independent particles of viruses are called , whose genetic material can be or double stranded DNA or . This is protected by a protein coat known as a .
Viruses with only a capsid are 'naked'. Viruses with an around this protein coat are 'enveloped'. This envelope of lipids can sometimes have .

Arrastra y suelta para completar el texto.

    virions
    single
    RNA
    capsid
    envelope of lipids
    glycoprotein spikes

Explicación

Pregunta 4 de 13

1

Select the statements about viral capsids which are CORRECT.

Selecciona una o más de las siguientes respuestas posibles:

  • Viral capsids are always symmetrical and made of repetitive structures.

  • Capsomers and protomers are the sub-units of capsids.

  • Protomers are made up of capsomers.

  • Capsids can be helical, icosahedral, or complex in shape.

Explicación

Pregunta 5 de 13

1

Which order of the steps of the viral life cycle is CORRECT?

Selecciona una de las siguientes respuestas posibles:

  • entry, attachment, synthesis, assembly, release

  • attachment, entry, assembly, synthesis, release

  • attachment, entry, synthesis, assembly, release

Explicación

Pregunta 6 de 13

1

Lytic=virulent and lysogenic=latent.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 7 de 13

1

Bacteriophages are the virions which have a capsid specialised to infect bacterial cells.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 8 de 13

1

Which statement about bacteriophage replication types is INCORRECT?

Selecciona una de las siguientes respuestas posibles:

  • Lysogenic cycles are temperate e.g. can kill the cell or live within it.

  • The lytic cycle ends in cell lysing.

  • The lytic cycle releases 10-20 virions.

  • Lytic and lysogenic cells both inject their DNA into the host cell in order to reproduce.

Explicación

Pregunta 9 de 13

1

Which statement BEST describes a prophage?

Selecciona una o más de las siguientes respuestas posibles:

  • A prophage is the phage genome of the bacteriophage, either integrated with the DNA of the Lysogen (bacterium) or floating free in its cytoplasm, able to produce a lytic phage.

  • A prophage is the inserted DNA from the bacteriophage which lives inside the host cell, known as the Lysogen.

  • The prophage lives in the Lysogen and can become a lytic phage.

Explicación

Pregunta 10 de 13

1

Which statement is true?

Selecciona una de las siguientes respuestas posibles:

  • Lytic insertion is followed by immediate degradation of host DNA while the lysogenic genome only becomes virulent when induction (environmental stress, UV irradiation) occurs.

  • Lytic insertion does not harm the host DNA until the final stage of the lytic cycle.

Explicación

Pregunta 11 de 13

1

Retroviruses must use the host cell's machinery, and their own enzyme Reverse Transcriptase, to make DNA from their RNA. An example is HIV.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 12 de 13

1

Naked viruses enter the cell via receptors (endocytosis). Enveloped viruses fuse their viral envelope with the host's membrane.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

Pregunta 13 de 13

1

The provirus (DNA of enveloped virus in host genome) is virulent.

Selecciona uno de los siguientes:

  • VERDADERO
  • FALSO

Explicación

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