BIOL 3444 EXAM 1 QUESTIONS AND
VERIFIED ANSWERS WELL GRADED
(NEW 2025/2026 UPDATE)
QUESTIONS WITH VERIFIED
ANSWERS 100% CORRECT /A+ GRADE
An annular stop is used for which type of microscopy? - CORRECT
ANSWER-D. phase contrast
Which of the following is the specific name for a stain that
colors the background but not the specimen? - CORRECT ANSWER-D.
negative stain
Which type of microscopy would work best for viewing internal
cell structures? - CORRECT ANSWER-D. transmission electron
microscopy
The Gram-staining procedure is best described as which of the
following? - CORRECT ANSWER-B. differential staining
When there is a substantial difference in refractive index
between two materials, which of the following describes what
will happen to light passing from one material to the other? -
CORRECT ANSWER-B. It will undergo a large amount of refraction.
,In microscopy, the focal length refers to which of the following?
- CORRECT ANSWER-D. the distance to the image point (at which all
light entering a lens is parallel)
Which of the following are pigments used in microscopy to
absorb and reflect light? - CORRECT ANSWER-B. chromophores
Negative staining is the standard approach used to visualize
which structure(s)? - CORRECT ANSWER-A. capsules
Which is a standard mordant used in flagella staining? - CORRECT
ANSWER-D. tannic acid
Which of the following pairs are common acid-fast staining
techniques? - CORRECT ANSWER-C. Ziehl-Neelsen and Kinyoun
Which is the primary stain used in the Ziehl-Neelsen
technique? - CORRECT ANSWER-B. carbolfuchsin
Which is the correct order of steps in Gram staining? - CORRECT
ANSWER-B. crystal violet stain, Gram's iodine mordant, ethanol
decolorization, safranin counterstain
It is important to fix bacterial smears on a slide for which of the
following reasons? - CORRECT ANSWER-A. to attach them to the slide
Which of the following is not commonly used for chemical
fixation? - CORRECT ANSWER-D. iodine
, Which of the following is not involved in preparing a bacterial
slide for Gram staining? - CORRECT ANSWER-D. preparing a wet
mount
Which of the following most specifically refers to stains with
positively charged chromophores? - CORRECT ANSWER-C. basic dyes
Which of the following most specifically refers to a stain that
dyes a specimen rather than the background? - CORRECT ANSWER-
D. positive stain
Which of the following describes the difference between the
Ziehl-Neelsen and Kinyoun acid-fast staining techniques? -
CORRECT ANSWER-C. The Ziehl-Neelsen technique uses heat and
the Kinyoun technique does not
Which of the following described the difference between gram-
positive and gram-negative cells that causes them to stain
differently after Gram staining? - CORRECT ANSWER-D. Gram-
positive cells have thicker peptidoglycan layers in their cell
walls than do gram-negative cells.
Which of the following would not potentially cause a gram-
positive cell to appear gram-negative after Gram staining? -
CORRECT ANSWER-A. counterstaining with crystal violet instead of
safranin
VERIFIED ANSWERS WELL GRADED
(NEW 2025/2026 UPDATE)
QUESTIONS WITH VERIFIED
ANSWERS 100% CORRECT /A+ GRADE
An annular stop is used for which type of microscopy? - CORRECT
ANSWER-D. phase contrast
Which of the following is the specific name for a stain that
colors the background but not the specimen? - CORRECT ANSWER-D.
negative stain
Which type of microscopy would work best for viewing internal
cell structures? - CORRECT ANSWER-D. transmission electron
microscopy
The Gram-staining procedure is best described as which of the
following? - CORRECT ANSWER-B. differential staining
When there is a substantial difference in refractive index
between two materials, which of the following describes what
will happen to light passing from one material to the other? -
CORRECT ANSWER-B. It will undergo a large amount of refraction.
,In microscopy, the focal length refers to which of the following?
- CORRECT ANSWER-D. the distance to the image point (at which all
light entering a lens is parallel)
Which of the following are pigments used in microscopy to
absorb and reflect light? - CORRECT ANSWER-B. chromophores
Negative staining is the standard approach used to visualize
which structure(s)? - CORRECT ANSWER-A. capsules
Which is a standard mordant used in flagella staining? - CORRECT
ANSWER-D. tannic acid
Which of the following pairs are common acid-fast staining
techniques? - CORRECT ANSWER-C. Ziehl-Neelsen and Kinyoun
Which is the primary stain used in the Ziehl-Neelsen
technique? - CORRECT ANSWER-B. carbolfuchsin
Which is the correct order of steps in Gram staining? - CORRECT
ANSWER-B. crystal violet stain, Gram's iodine mordant, ethanol
decolorization, safranin counterstain
It is important to fix bacterial smears on a slide for which of the
following reasons? - CORRECT ANSWER-A. to attach them to the slide
Which of the following is not commonly used for chemical
fixation? - CORRECT ANSWER-D. iodine
, Which of the following is not involved in preparing a bacterial
slide for Gram staining? - CORRECT ANSWER-D. preparing a wet
mount
Which of the following most specifically refers to stains with
positively charged chromophores? - CORRECT ANSWER-C. basic dyes
Which of the following most specifically refers to a stain that
dyes a specimen rather than the background? - CORRECT ANSWER-
D. positive stain
Which of the following describes the difference between the
Ziehl-Neelsen and Kinyoun acid-fast staining techniques? -
CORRECT ANSWER-C. The Ziehl-Neelsen technique uses heat and
the Kinyoun technique does not
Which of the following described the difference between gram-
positive and gram-negative cells that causes them to stain
differently after Gram staining? - CORRECT ANSWER-D. Gram-
positive cells have thicker peptidoglycan layers in their cell
walls than do gram-negative cells.
Which of the following would not potentially cause a gram-
positive cell to appear gram-negative after Gram staining? -
CORRECT ANSWER-A. counterstaining with crystal violet instead of
safranin
