BIO 250 Final Exam Study Guide Latest Update
2025-2026 130 Questions and 100% Verified
Correct Answers Guaranteed A+
__________ membranes allow some molecules to pass but not others.
A. Permeable
B. Inverted monolayer
C. Selectively permeable
D. Impermeable - CORRECT ANSWER: C. Selectively permeable
10. Predict how the plasma membrane fatty acid composition would change as the
temperature of the habitat of an aquatic bacterial species warms from 2oC to 15oC
during the spring and summer months.
A. The percentage of saturated fatty acids would increase.
B. The percentage of unsaturated fatty acids would increase.
C. The percentage of saturated fatty acids would decrease.
D. The percentage of saturated fatty acids would remain unchanged. - CORRECT
ANSWER: A. The percentage of saturated fatty acids would increase.
110. Which bacterial structure may survive if temperatures applied during food
preservation processes are too low?
A. Flagella
B. Endospores
C. Plasma membranes
D. Ribosomes - CORRECT ANSWER: B. Endospores
111. Which of the following contribute to the environmental resistance of bacterial
endospores?
,A. Spore coat
B. Low water content of endospore
C. Presence of calcium dipicolinate
D. Lower pH
E. All of the choices are correct. - CORRECT ANSWER: E. All of the choices are
correct.
16. Who of the following developed a set of criteria that could be used to establish a
causative link between a particular microorganism and a particular disease?
A. Fracastoro
B. Koch
C. Pasteur
D. Lister - CORRECT ANSWER: B. Koch
22. Which of the following structures is NOT found in an endospore?
A. Capsule
B. Coat
C. Core
D. Exosporium - CORRECT ANSWER: A. Capsule
23. As the magnification of a series of objective lenses increases, the working distance
A. increases.
B. decreases.
C. stays the same.
D. cannot be predicted. - CORRECT ANSWER: B. decreases.
24. Prior to staining, smears of microorganisms are heat-fixed in order to
A. allow eventual visualization of internal structures.
,B. ensure removal of dust particles from the slide surface.
C. attach it firmly to the slide.
D. create small pores in cells that facilitates binding of stain to cell structures. -
CORRECT ANSWER: C. attach it firmly to the slide.
25. Acid-fast organisms such as Mycobacterium tuberculosis contain __________
constructed from mycolic acids in their cell walls.
A. proteins
B. carbohydrates
C. lipids
D. peptidoglycan - CORRECT ANSWER: C. Lipids
26. In the Gram-staining procedure, the primary stain is A. iodine.
B. safranin.
C. crystal violet.
D. alcohol. - CORRECT ANSWER: C. crystal violet.
27. In the Gram-staining procedure, the decolorizer is A. iodine.
B. safranin.
C. crystal violet.
D. ethanol or acetone. - CORRECT ANSWER: D. ethanol or acetone.
35. Which of the following is considered to be a differential staining procedure?
A. Gram stain
B. Acid-fast stain
C. Both Gram stain and Acid-fast stain
D. Leifson's flagella stain - CORRECT ANSWER: C. Both Gram stain and Acid-fast stain
, 43. Bacterial cells that are variable in shape are called A. vibrio.
B. pleomorphic.
C. coccobacilli.
D. hyphal. - CORRECT ANSWER: B. pleomorphic.
44. The term used to describe bacteria that are intermediate in shape between spherical
and rod-shaped is
A. cocci.
B. bacilli.
C. vibrio.
D. coccobacilli. - CORRECT ANSWER: D. coccobacilli.
45. Square planar arrangement of cells that forms when round bacteria remain attached
to each other during reproduction are called
A. streptococci.
B. staphylococci.
C. tetrads.
D. sarcinae. - CORRECT ANSWER: C. tetrads.
46. Flexible bacteria with a helical shape are called A. vibrios.
B. spirilla.
C. spirochetes.
D. coccobacilli. - CORRECT ANSWER: C. spirochetes.
46. The Gram-staining procedure is an example of ________________________.
A. simple staining
B. negative staining
C. differential staining
2025-2026 130 Questions and 100% Verified
Correct Answers Guaranteed A+
__________ membranes allow some molecules to pass but not others.
A. Permeable
B. Inverted monolayer
C. Selectively permeable
D. Impermeable - CORRECT ANSWER: C. Selectively permeable
10. Predict how the plasma membrane fatty acid composition would change as the
temperature of the habitat of an aquatic bacterial species warms from 2oC to 15oC
during the spring and summer months.
A. The percentage of saturated fatty acids would increase.
B. The percentage of unsaturated fatty acids would increase.
C. The percentage of saturated fatty acids would decrease.
D. The percentage of saturated fatty acids would remain unchanged. - CORRECT
ANSWER: A. The percentage of saturated fatty acids would increase.
110. Which bacterial structure may survive if temperatures applied during food
preservation processes are too low?
A. Flagella
B. Endospores
C. Plasma membranes
D. Ribosomes - CORRECT ANSWER: B. Endospores
111. Which of the following contribute to the environmental resistance of bacterial
endospores?
,A. Spore coat
B. Low water content of endospore
C. Presence of calcium dipicolinate
D. Lower pH
E. All of the choices are correct. - CORRECT ANSWER: E. All of the choices are
correct.
16. Who of the following developed a set of criteria that could be used to establish a
causative link between a particular microorganism and a particular disease?
A. Fracastoro
B. Koch
C. Pasteur
D. Lister - CORRECT ANSWER: B. Koch
22. Which of the following structures is NOT found in an endospore?
A. Capsule
B. Coat
C. Core
D. Exosporium - CORRECT ANSWER: A. Capsule
23. As the magnification of a series of objective lenses increases, the working distance
A. increases.
B. decreases.
C. stays the same.
D. cannot be predicted. - CORRECT ANSWER: B. decreases.
24. Prior to staining, smears of microorganisms are heat-fixed in order to
A. allow eventual visualization of internal structures.
,B. ensure removal of dust particles from the slide surface.
C. attach it firmly to the slide.
D. create small pores in cells that facilitates binding of stain to cell structures. -
CORRECT ANSWER: C. attach it firmly to the slide.
25. Acid-fast organisms such as Mycobacterium tuberculosis contain __________
constructed from mycolic acids in their cell walls.
A. proteins
B. carbohydrates
C. lipids
D. peptidoglycan - CORRECT ANSWER: C. Lipids
26. In the Gram-staining procedure, the primary stain is A. iodine.
B. safranin.
C. crystal violet.
D. alcohol. - CORRECT ANSWER: C. crystal violet.
27. In the Gram-staining procedure, the decolorizer is A. iodine.
B. safranin.
C. crystal violet.
D. ethanol or acetone. - CORRECT ANSWER: D. ethanol or acetone.
35. Which of the following is considered to be a differential staining procedure?
A. Gram stain
B. Acid-fast stain
C. Both Gram stain and Acid-fast stain
D. Leifson's flagella stain - CORRECT ANSWER: C. Both Gram stain and Acid-fast stain
, 43. Bacterial cells that are variable in shape are called A. vibrio.
B. pleomorphic.
C. coccobacilli.
D. hyphal. - CORRECT ANSWER: B. pleomorphic.
44. The term used to describe bacteria that are intermediate in shape between spherical
and rod-shaped is
A. cocci.
B. bacilli.
C. vibrio.
D. coccobacilli. - CORRECT ANSWER: D. coccobacilli.
45. Square planar arrangement of cells that forms when round bacteria remain attached
to each other during reproduction are called
A. streptococci.
B. staphylococci.
C. tetrads.
D. sarcinae. - CORRECT ANSWER: C. tetrads.
46. Flexible bacteria with a helical shape are called A. vibrios.
B. spirilla.
C. spirochetes.
D. coccobacilli. - CORRECT ANSWER: C. spirochetes.
46. The Gram-staining procedure is an example of ________________________.
A. simple staining
B. negative staining
C. differential staining
