required information\ngram positive cell\n1. why must fresh cells be used when performing a gram stain?\nall…

required information\ngram positive cell\n1. why must fresh cells be used when performing a gram stain?\nall of these are reasons why fresh cells must be used for gram staining.\nold cells may not gram - stain properly.\nas cells ages, they wont stick to the slide.\nfresh cells do not smell as badly as older cells.\n2. after grams iodine is added, what color do the cells appear under a light microscope?\nall cells appear colorless\nall cells appear pink/red\nsome cells may be purple and some may be pink/red\nall cells appear purple\n3. when ethanol is applied correctly, gram - positive cells appear ________ and gram - negative cells appear ________.\ncolorless; purple\npink/red; purple\npurple; colorless\npurple; pink/red

required information\ngram positive cell\n1. why must fresh cells be used when performing a gram stain?\nall of these are reasons why fresh cells must be used for gram staining.\nold cells may not gram - stain properly.\nas cells ages, they wont stick to the slide.\nfresh cells do not smell as badly as older cells.\n2. after grams iodine is added, what color do the cells appear under a light microscope?\nall cells appear colorless\nall cells appear pink/red\nsome cells may be purple and some may be pink/red\nall cells appear purple\n3. when ethanol is applied correctly, gram - positive cells appear ________ and gram - negative cells appear ________.\ncolorless; purple\npink/red; purple\npurple; colorless\npurple; pink/red

Answer

Brief Explanations:

  1. Old cells can have changes in cell - wall properties that affect Gram - staining results, making fresh cells necessary.
  2. Gram's iodine forms a complex with crystal violet, and all cells appear purple at this stage.
  3. Gram - positive cells retain the crystal violet - iodine complex and remain purple, while gram - negative cells lose the complex and take up the counter - stain (safranin) to appear pink/red.

Answer:

  1. Old cells may not Gram - stain properly.
  2. All cells appear purple
  3. purple; pink/red