Micro Bio

Prions

1. Prions are resistant to inactivation by heating to 90 degrees Celcius, which will inactivate viruses

2. Prion infection is not sensitive to radiation treatment that damages viruses genomes

3. Prions are not destroyed by enzymes that digest DNA or RNA

4. Proteins are sensitive to protein denaturing agents, such as phenol and urea.

Which of the following statements provides support for the idea that viruses are intracellular obligate parasites?

They cannot reporduce themselves outside a host

The definition of lysogeny is

Phage DNA is incorporated into the host cell DNA and remain dormant

The definition of a naked virus

A virus with no envelope

A virus envelope is acquired during which of the following steps?

Moving through various membranous organelles and through exocytosis

Which of the following is false about viruses

They all contain and envelope

If a virus infects a cell, which of the following may result

can incorporate the bacterial cell chromosome and remain latent, may take over the the genetic machinery of the cell, the host cell may burst

A bacteriophage is a

virus that infects bacteria

The mature virus particle together with its envelope is called

virion

The _____ is the protein coat of the virus

capsid

Which of the following sequence is correct during a viral invasion of a cell

Absorbption, penetration, biosynthesis, maturation, release

A basic characteristic of lysogenic bacteria is their natural immunity to all types of prophages

False

Virus can infect any of the following (plant, animal, bacteria, fungi, protista, viruses)

True

Certain viruses contain both RNA and DNA

False

Naked viruses generally are more resistant to chemical disinfectants (chlorine, hydrogen peroxide) than enveloped viruses

True

Syncytia may contain several nuclei in their cytoplasm

True

The terms bacteriophage and phage are used interchangeably

True

Combination between a bacterium and a temperate phage is termed

Lysogen

Immunity of the bacterial cell and its capability to make toxins are two types of

Lysogenic Conversion

Visible effects that viruses have on cells they infect is termed

Cytopathic Effects

The shift from Lysogenic Cycle to Lytic Cycle are known as

Induction

The protein outer coat of the virus is called _____, and the subunits that compose that surrounding protein coat are known as _____

capsid, capsomeres

The stage in viral replication cycle at which assembly of newly synthesized viral components into complete virions is called

Maturation

In certain viruses, spikes or glycoproteins cause various red blood cells to clump or clusters, a phenomenon known as

Hemagglutination

Upon infection by viruses, adjacent cells tend to fuse, forming giant multinucleate cells called

Syncytia

The viral DNA insert within the bacterial chromosome is called

Prophage or Provirus

Name 4 types of viruses that infect different human tissues, organs, and systems discussed in class along with the tissues affected

Deumotropic attacks the skin, neurotropic (nervous system/tissue), pneumotropic (lungs and respiratory), viscerotropic (internal organs of digestive system