Viruses & Bacteria

A typical virus consists of

• a protein coat and a cytoplasm core

• a carbohydrate coat and a nucleic acid core

• a protein coat and a nucleic acid core

• a polysaccharide coat and a nucleic acid core

Which nucleic acid serves as the hereditary material for viruses?

• DNA

• RNA

• They don't have hereditary material.

• DNA or RNA depending on the virus.

Which of these is the best description of a virus?

• a noncellular living organism

• one of the smallest bacteria known

• a member of the kingdom Virusae

• chemical complexes of RNA or DNA protected by protein

Which statement is true about prokaryotes?

• They contain a single circular DNA molecule as the genetic material.

• They lack ribosomes.

• They usually lack a cell wall.

• They divide by mitosis.

Methanogens and halophiles are

• members of the bacteria domain.

• members of the achaea domain.

• immunoviruses.

• members of the eukarya domain.

All bacteria are pathogenic.

• True

• False

Antigenic drift is a mechanism of viral evolution.

• True

• False

Bacteria were the most prevalent life forms during which time period?

• 4.6 bya

• 3.5 bya

• 200,000 years ago

• 1.8 bya

Which term below describes the ability of bacteria to break down pollutants?

• nitrogen fixation

• carbon fixation

• probiotics

• bioremediation

Halophiles thrive in ___ environments.

• hot

• cold

• salty

• anaerobic