View the animation below, then complete the quiz to test your knowledge of the concept.
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1 | The proper sequence of reagents in the Gram stain procedure is |
| A) | iodine, ethanol, safranin, crystal violet. |
| B) | safranin, crystal violet, ethanol, iodine. |
| C) | crystal violet, ethanol, iodine, safranin. |
| D) | crystal violet, iodine, ethanol, safranin. |
| E) | ethanol, iodine, crystal violet, safranin. |
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2 | After performing a Gram stain of a mixed culture of gram positive and gram negative cells, you shout: “Oops, I forgot the iodine step!” What would you expect to see if you observed the slide under the microscope? |
| A) | Purple gram positive and pink gram negative cells |
| B) | Pink gram positive and purple gram negative cells |
| C) | Colorless gram positive and pink gram negative cells |
| D) | Pink gram positive and pink gram negative cells |
| E) | Colorless gram positive and colorless gram negative cells |
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3 | The Gram stain of a bacterial cell is based on the chemical properties of its |
| A) | cell membrane. |
| B) | cell wall. |
| C) | capsule. |
| D) | ribosomes. |
| E) | nucleus. |
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4 | Acetone can be used as the decolorizer in the Gram stain procedure. |
| A) | True |
| B) | False |
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5 | The Gram stain can only be performed on cultures grown in liquid media. |
| A) | True |
| B) | False |