Explore topic-wise MCQs in Microbiology.

This section includes 27 Mcqs, each offering curated multiple-choice questions to sharpen your Microbiology knowledge and support exam preparation. Choose a topic below to get started.

1.

How many oxygen molecules are required in the fermentation of one molecule of glucose to ethanol and CO?

A. 0
B. 1
C. 2
D. 36
Answer» B. 1
2.

In cellular metabolism, O is used

A. to provide electrons for photophosphorylation
B. in glycolysis
C. as a terminal electron acceptor
D. in the Krebs cycle
Answer» D. in the Krebs cycle
3.

Organisms can synthesize ATP by oxidative phosphorylation when they

A. ferment
B. oxidize glucose to pyruvate
C. pass electrons from the oxidation of chlorophyll through an electron transport system
D. pass electrons to oxygen through an electron transport system containing cytochromes
Answer» E.
4.

How many molecules of carbon dioxide will be given off during ten turns of the Krebs cycle?

A. 10
B. 20
C. 30
D. 40
Answer» C. 30
5.

In cellular metabolism, O2 is used

A. to provide electrons for photophosphorylation
B. in glycolysis
C. as a terminal electron acceptor
D. in the Krebs cycle
Answer» D. in the Krebs cycle
6.

The enzymes that catalyze the reactions of the Krebs cycle are found in which subcellular organelle of eukaryotes?

A. Mitochondrion
B. Chloroplast
C. Ribosome
D. Endoplasmic reticulum
Answer» B. Chloroplast
7.

Fatty acids are oxidized to acetyl-CoA by which of the following pathways?

A. -oxidation
B. Entner-Doudoroff
C. pentose phosphate pathway
D. Embden-Meyerhof pathway
Answer» B. Entner-Doudoroff
8.

In anaerobic respiration, the final electron acceptor can be

A. oxygen
B. nitrate
C. pyruvate
D. acetyl-CoA
Answer» C. pyruvate
9.

Which one of the following is not produced in any of the steps of glycolysis?

A. NAD
B. <sup>+</sup>
C. NADH
D. ADP
E. ATP
Answer» B. <sup>+</sup>
10.

The number of ATP molecules produced from one glucose molecule by a bacterium producing lactic acid is

A. greater than producing ethanol
B. lesser than producing ethanol
C. approximately equal to producing ethanol
D. none of these
Answer» D. none of these
11.

Most bacterial fermentations yield how many net ATP molecules per molecule of glucose?

A. 1
B. 2
C. 4
D. 6
Answer» C. 4
12.

The amount of ATP produced by a cell from glucose when metabolizing it by fermentation means is

A. greater than by aerobic metabolism
B. lesser than by aerobic metabolism
C. exactly or approximately equal to by aerobic metabolism
D. none of these
Answer» C. exactly or approximately equal to by aerobic metabolism
13.

Which one of the following is produced in the greatest numbers during one turn of the Krebs cycle?

A. NADH
B. Acetyl-CoA
C. FADH
D. <sub>2</sub>
E. ATP
Answer» B. Acetyl-CoA
14.

Which of the following is accomplished in chemiosmosis?

A. The oxidation of ATP
B. The oxidation of water
C. The oxidation of NADH
D. The oxidation of CO
E. <sub>2</sub>
Answer» D. The oxidation of CO
15.

A yeast or fungal cell produces how many net ATP molecules per molecule of glucose when completely oxidized?

A. 32
B. 34
C. 36
D. 38
Answer» D. 38
16.

Before most molecules can enter the Krebs citric acid cycle, they must be converted to

A. citric acid
B. oxaloacetic acid
C. NADH or FADH
D. acetyl-CoA
Answer» E.
17.

How many oxygen molecules are required in the fermentation of one molecule of glucose to ethanol and CO2?

A. 0
B. 1
C. 2
D. 36
Answer» B. 1
18.

The amount of energy (cal/mole) in an ATP molecule produced by a cell from glucose by fermentation is

A. greater than aerobic metabolism
B. less than aerobic metabolism
C. exactly or approximately equal to aerobic metabolism
D. none of the above
Answer» D. none of the above
19.

Glucose can be broken down to pyruvate by

A. Entner-Doudoroff pathway
B. tricarboxylic acid cycle
C. both (a) and (b)
D. none of these
Answer» B. tricarboxylic acid cycle
20.

Aerobic respiration differs from anaerobic respiration in which of the following respects?

A. Anaerobic respiration is glycolysis
B. Aerobic respiration requires the electron transport chain
C. The final electron acceptors are different
D. Aerobic respiration produces less ATP
Answer» D. Aerobic respiration produces less ATP
21.

In lactic acid fermentation, the final electron acceptor would be

A. fructose
B. pyruvate
C. glucose
D. acetyl-CoA
Answer» C. glucose
22.

The amount of ATP that can be obtained by complete oxidation of a glucose by a bacterium is

A. greater than by a yeast cell
B. lesser than by a yeast cell
C. exactly or approximately equal to by a yeast cell
D. none of these
Answer» B. lesser than by a yeast cell
23.

The final electron acceptor in the electron transport chain is

A. CoQ
B. a cytochrome
C. FMN
D. oxygen
Answer» E.
24.

The enzymes for glycolysis are located

A. on the inner surface of the cell membrane
B. on the inner membrane of the mitochondrion
C. on the outer membrane of the chloroplast
D. in the cytoplasm
Answer» E.
25.

Suppose a eukaryotic cell had a mutation that prevented the production of cytochrome c. As a result of this mutation, which of the following processes would not occur?

A. Cellular respiration
B. Photosynthesis
C. Mitosis
D. Cell wall synthesis
Answer» B. Photosynthesis
26.

In glycolysis, ATP is created by

A. photophosphorylation
B. the chemiosmotic mechanism
C. substrate level phosphorylation
D. the pentose phosphate pathway
Answer» D. the pentose phosphate pathway
27.

For each pair of electrons passing from NADH located inside the mitochondria to oxygen, how many ATP molecules can be generated?

A. 1
B. 2
C. 3
D. 4
Answer» D. 4