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| 1 | |
A virus is described based upon |
| | A) | its type of nucleic acid. |
| | B) | its size and shape. |
| | C) | the presence or absence of an outer envelope. |
| | D) | a virus is described based on all three of these things. |
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| 2 | |
A virus is called naked if |
| | A) | its outer covering consists of a capsid and no membranous envelope. |
| | B) | its outer covering consists of a capsid and a membranous envelope. |
| | C) | it has no capsid or membranous envelope. |
| | D) | its outer covering consists of a membranous envelope but no capsid. |
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| 3 | |
Bacteriophages are viruses that |
| | A) | infect tobacco plants. |
| | B) | undergo a lytic life cycle. |
| | C) | undergo a lysogenic life cycle. |
| | D) | parasitize bacteria. |
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| 4 | |
The most common life cycle for bacteriophages is |
| | A) | the lysogenic cycle. |
| | B) | the lytic cycle. |
| | C) | a hybrid life cycle that mixes the lytic and lysogenic cycle. |
| | D) | dependent on the type of bacteria being invaded. |
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| 5 | |
When a virus reproduces during the lytic cycle it takes over the _________ of the host cell in order to replicate its DNA. |
| | A) | respiratory pathway |
| | B) | mitochondria |
| | C) | metabolic machinery |
| | D) | nucleus |
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| 6 | |
Viruses with the lysogenic life cycle __________; these viruses __________ to produce lysogenic cells. |
| | A) | immediately produce phages; integrate their DNA into the bacterial DNA |
| | B) | do not immediately produce phages; cause the bacterial cell to break open |
| | C) | immediately produce phages; cause the bacterial cell to break open |
| | D) | do not immediately produce phages; integrate their DNA into the bacterial DNA |
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| 7 | |
True or False: Plant viruses produce billions of dollars of loss in agricultural crops because they kill their hosts. |
| | A) | True |
| | B) | False |
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| 8 | |
DNA viruses that invade human and animal cells use reproductive strategies |
| | A) | during which viral proteins are synthesized without the help of the host ribosomes. |
| | B) | entirely unlike those of any other viruses. |
| | C) | similar to those of the plant-invading TMV, entering through wounds. |
| | D) | similar to those of bacteriophages, taking over the cell’s machinery to replicate. |
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| 9 | |
A retrovirus, like HIV, is unique because it |
| | A) | causes the cell to break open after it reproduces. |
| | B) | inserts a copy of its genome into the host genome by making a DNA copy of its RNA. |
| | C) | uses the host cell’s machinery to replicate its own genetic material. |
| | D) | is a naked strand of RNA. |
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| 10 | |
The iron-sulfur world hypothesis accounts for which detail about earth’s early atmosphere, which is not well-accounted for in the prebiotic soup hypothesis? |
| | A) | the presence of oxygen |
| | B) | the abundance of nitrogen gas |
| | C) | the abundance of ammonia |
| | D) | the need for a heat source |
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| 11 | |
It was essential that the first macromolecule be able to |
| | A) | store genetic information. |
| | B) | replicate. |
| | C) | combine to form proteins. |
| | D) | store genetic information and self-replicate. |
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| 12 | |
A protobiont may have evolved into the first cell by first acquiring _________ for protection, then __________ for growth and nutrition, and finally a DNA information system that could be transcribed to RNA and translated to protein, as seen in cellular life today. |
| | A) | a plasma membrane, a metabolism |
| | B) | a cell wall, chloroplasts |
| | C) | a plasma membrane, chloroplasts |
| | D) | a cell wall, a metabolism |
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| 13 | |
If not a chemosynthetic cell, the protocell was likely a __________, an organism that takes in preformed food. |
| | A) | omnivore |
| | B) | photoautotroph |
| | C) | autotroph |
| | D) | heterotroph |
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| 14 | |
Prokaryotic cells have DNA contained within a |
| | A) | nucleus. |
| | B) | nucleoid with no nuclear envelope. |
| | C) | ribosome. |
| | D) | capsid. |
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| 15 | |
Bacteria have a cell wall that contains |
| | A) | a capsule of pure protein. |
| | B) | a double layer of phospholipids. |
| | C) | peptidoglycan. |
| | D) | an inner and outer membrane. |
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| 16 | |
Bacteria occur in which basic shape(s)? |
| | A) | rod |
| | B) | sphere |
| | C) | spiral |
| | D) | Bacteria occur in all three of these shapes. |
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| 17 | |
Bacteria reproduce via |
| | A) | asexual means called binary fission. |
| | B) | conjugation. |
| | C) | the formation of endospores. |
| | D) | cytokinesis. |
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| 18 | |
Bacteria undergo genetic recombination by |
| | A) | conjugation, which involves the temporary joining of two bacteria. |
| | B) | transformation, which occurs when a bacterium picks up free DNA from its surrounding. |
| | C) | transduction, which involves the injection of bacteriophage DNA into a donor cell. |
| | D) | Bacteria undergo genetic recombination by all three of these methods. |
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| 19 | |
Most bacteria require a constant supply of oxygen and are thus |
| | A) | facultative anaerobes. |
| | B) | aerobic. |
| | C) | obligate anaerobes. |
| | D) | saprotrophs. |
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| 20 | |
Archaea include |
| | A) | mutualistic, parasitic, and commensalistic bacteria. |
| | B) | Gram-positive, Gram-negative, and wall-less bacteria. |
| | C) | methanogens, halophiles, and thermoacidophiles. |
| | D) | obligate and facultative anaerobes. |
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