CH.20

Which of the following could be used to grow lysogenic viruses in the laboratory? bacteria All of the choices could be used. chicken eggs cell culture

All of the choices could be used.

Which of the following is not part of the reproduction cycle of HIV? Biosynthesis of the viral mRNA Reverse transcription of the viral DNA Reverse transcription of the viral RNA Maturation of the viruses

Reverse transcription of the viral DNA

What are the two Domains that the prokaryotes are classified under? Archaea & Eukarya Eukarya & Bacteria Protista & Archaea Archaea & Bacteria

Archaea & Bacteria

Which of these is the best description of a virus? a cell at the boundary between living and nonliving things chemical complexes of RNA or DNA protected by protein shell a member of the kingdom Virusae one of the smallest bacteria known a noncellular living organism

chemical complexes of RNA or DNA protected by protein shell

The innermost portion of a virus' structure is made up of; a protein capsid. either DNA or RNA. both DNA and RNA. spikes. a membranous envelope.

either DNA or RNA.

When conditions are unfavorable, some bacteria form; thylakoids. galls. pili. endospores. capsules.

endospores.

An enveloped virus enters a host cell by; Any of the choices are correct. fusion of its envelope with the host cell's plasma envelope. endocytosis. Attaching to the host cell's membrane and then injecting its DNA or RNA into the host cell. injecting its DNA or RNA into the host cell.

fusion of its envelope with the host cell's plasma envelope.

Pasteur chose the Latin root word for "virus" meaning; extremely small. particle. poison. non-living. contagious.

poison.

Viruses are categorized according to all of the following EXCEPT; their method of reproduction, whether asexual or sexual. the presence of absence of an envelope. their type of nucleic acid. size and shape.

their method of reproduction, whether asexual or sexual.

Bacterial cells pick up free pieces of DNA that were secreted by live bacteria or released from dead bacteria in their environment. This process is called; transduction. replication. infection. conjugation. transformation.

transformation.

Some, but not all, virus capsids are surrounded by ________. a protein spore coat either DNA or RNA a protein capsid a membranous envelope

a membranous envelope

The cycle of viral infection in which the viral DNA is integrated into the host's DNA is called the ________ cycle. lysogenic lysosome lysol lytic lysozyme

lysogenic

Influenza strains that sweep around the world often carry names such as Shanghai H1N1 or Mexico City H2N2. The viruses vary in H and N surface proteins because; when infected people develop immunity to the present virus, strains that mutate sufficiently to be outside the range of immunity are soon spread in highly populated areas. the viruses reproduce and attack people in cities more often. these viruses emerged as stray DNA from the genomes of people in these cities. this is where the antibodies of immune people began to break down and the old virus was again virulent.

when infected people develop immunity to the present virus, strains that mutate sufficiently to be outside the range of immunity are soon spread in highly populated areas.

Prokaryotes generally range in size from; 20-300 mm. 50-100nm. 10-100 µm. 10-400 nm. 1-10 µm.

1-10 µm.

Which description best describes the cell wall of a Gram-positive bacteria? It is composed of a single plasma membrane and a thin outer layer of cellulose. It is composed of a single plasma membrane and a thin outer layer of peptidoglycan. It is composed of a double layer in the plasma membrane and a thick outer layer of peptidoglycan. It is composed of a double layer in the plasma membrane and a thin outer layer of peptidoglycan. It is composed of a single plasma membrane and a thick outer layer of peptidoglycan.

It is composed of a single plasma membrane and a thick outer layer of peptidoglycan.

Which group of Archaea are chemoautotrophic anaerobes that will use hydrogen as an electron donor? Methanogens Cyanobacteria Thermoacidophiles Halophiles

Thermoacidophiles

Which statement is true about prokaryotes? They do not divide by mitosis. They lack ribosomes. They contain a nucleus. They contain a long linear strand of DNA as the genetic material. They usually lack a cell wall.

They contain a long linear strand of DNA as the genetic material.

All of the following are means of genetic recombination in prokaryotes EXCEPT crossing over. transformation. transduction. conjugation.

crossing over.

In order to infect a cell, a virus must; have a special protein on its surface that can interact with a protein on the surface of the host cell. inject its protein into the cell while the nucleic acid remains attached to the host cell surface. actively burrow through the cell wall or cell membrane of the host cell to reach the cell's nucleus. produce a special extension of its cytoplasm when it comes into contact with the appropriate host cell.

have a special protein on its surface that can interact with a protein on the surface of the host cell.

If a virus is latent, it; is easy to develop immunity against it. has not entered a lysogenic cycle. If a virus is latent, it is not actively replicating. is gaining a new envelope via "budding." cannot be a retrovirus. is not actively replicating.

is not actively replicating.