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This section includes 205 Mcqs, each offering curated multiple-choice questions to sharpen your Life Sciences knowledge and support exam preparation. Choose a topic below to get started.
101. |
The TCA cycle is regulated by which of the following enzymes? |
A. | citrate synthase |
B. | isocitrate dehydrogenase |
C. | malate dehydrogenase |
D. | succinate dehydrogenase |
Answer» C. malate dehydrogenase | |
102. |
Protein molecules can easily pass into the cell for being utilized for energy production. |
A. | True |
B. | False |
C. | May be |
D. | Can't say |
Answer» C. May be | |
103. |
Age, Gender, Body size and climate determine the |
A. | growth rate of an individual |
B. | basal metabolic rate |
C. | basal hydrolysis rate |
D. | pressure influence on growth rate |
Answer» C. basal hydrolysis rate | |
104. |
Which of the following pathway is common for oxidation of carbohydrates, lipids and amino acids? |
A. | Calvin cycle |
B. | Electron transport chain |
C. | TCA cycle |
D. | Pentose phosphate pathway |
Answer» D. Pentose phosphate pathway | |
105. |
Phosphoenolpyruvate (PEP) is converted to oxaloacetate by the enzyme PEP deaminase. |
A. | True |
B. | False |
C. | May be |
D. | Can't say |
Answer» C. May be | |
106. |
If ΔG of a chemical reaction has a negative value, the reaction |
A. | releases energy |
B. | requires energy |
C. | both (a) and (b) |
D. | none of these |
Answer» B. requires energy | |
107. |
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 | |
108. |
DNA gyrase is a ______________ protein. |
A. | helix-unwinding |
B. | helix-destabilizing |
C. | helix-relaxing |
D. | helix-winding |
Answer» D. helix-winding | |
109. |
Standard free energy change (ΔG) can be expressed as |
A. | ΔG° = -RTlnkeq |
B. | ΔG° = RTlnkeq |
C. | ΔG° = R/Tlnkeq |
D. | ΔG° = -RT/lnkeq |
Answer» B. ΔG° = RTlnkeq | |
110. |
The chromosome of a typical bacterium is ________________ |
A. | circular double-stranded DNA |
B. | circular single-stranded DNA |
C. | double-helix DNA |
D. | single stranded DNA |
Answer» B. circular single-stranded DNA | |
111. |
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 | |
112. |
In anaerobic respiration, the final electron acceptor can be |
A. | oxygen |
B. | nitrate |
C. | pyruvate |
D. | acetyl-CoA |
Answer» C. pyruvate | |
113. |
Physically tiring jobs may result in basal metabolic rate of |
A. | 480 kJ |
B. | 850 kJ |
C. | 1500 kJ |
D. | 2050 kJ |
Answer» E. | |
114. |
DAHP synthetase catalyzes the condensation of |
A. | erythrose-4-phosphate |
B. | phosphoenol pyruvate |
C. | both (a) and (b) |
D. | phenylalanine |
Answer» D. phenylalanine | |
115. |
How many ATPs are paid back during Pentose phosphate Pathway? |
A. | 1 |
B. | 3 |
C. | 4 |
D. | 5 |
Answer» B. 3 | |
116. |
Which of the following acts as chemical reductant in bacterial photosynthesis? |
A. | oxygen |
B. | water |
C. | hydrogen sulphide |
D. | ammonia |
Answer» D. ammonia | |
117. |
The region in which bacteriochlorophyll can absorb light is _________ |
A. | ultraviolet region |
B. | infrared region |
C. | visible region |
D. | microwave region |
Answer» C. visible region | |
118. |
The enzymes present in glyoxylate cycle are which type of enzymes? |
A. | reductase enzymes |
B. | anaplerotic enzymes |
C. | transferase enzymes |
D. | hydrolase enzymes |
Answer» C. transferase enzymes | |
119. |
Which molecule will combine with the four-carbon oxaloacetate in the TCA cycle to form the six-carbon citrate? |
A. | lactic acid |
B. | NADH |
C. | ATP |
D. | acetyl-CoA |
Answer» E. | |
120. |
An essential process connected with photosynthesis is |
A. | photolysis |
B. | synthesis of glucose |
C. | photophosphorylation |
D. | electron transfer |
Answer» B. synthesis of glucose | |
121. |
Chlorobium sp. is which type of bacteria? |
A. | Purple Sulphur Bacteria |
B. | Purple Non-sulphur Bacteria |
C. | Green Sulphur bacteria |
D. | Green Non-sulphur bacteria |
Answer» D. Green Non-sulphur bacteria | |
122. |
Where are bacteriochlorophyll present in the cell? |
A. | chloroplast |
B. | cytoplasm |
C. | mitochondria |
D. | membrane |
Answer» E. | |
123. |
Most bacterial fermentations yield how many net ATP molecules per molecule of glucose? |
A. | 1 |
B. | 2 |
C. | 4 |
D. | 6 |
Answer» C. 4 | |
124. |
High energy transfer compounds are capable of |
A. | accepting large amounts of free energy |
B. | transferring large amounts of free energy |
C. | measuring free energy |
D. | none of the above |
Answer» C. measuring free energy | |
125. |
The ribosome of E.coli is made up of which two subunits? |
A. | 60S and 40S |
B. | 60S and 30S |
C. | 50S and 40S |
D. | 50S and 30S |
Answer» E. | |
126. |
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 | |
127. |
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 | |
128. |
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. | |
129. |
In aerobic respiration, the terminal electron acceptor is |
A. | oxygen |
B. | nitrogen |
C. | hydrogen |
D. | nitrate |
Answer» B. nitrogen | |
130. |
The acquisition energy by glucose fermentation requires |
A. | substrate-level phosphorylation |
B. | electron transport of electrons from NADH |
C. | long-chain fatty acid oxidation |
D. | the enzyme formic-hydrogen lyase |
Answer» B. electron transport of electrons from NADH | |
131. |
Free energy change (ΔG) of a reaction is referred as the amount of energy |
A. | liberated during reaction |
B. | taken up during reaction |
C. | liberated or taken up during reaction |
D. | none of these |
Answer» D. none of these | |
132. |
Which of the following intermediates of TCA cycle act as amino acid precursors? |
A. | oxaloacetic acid |
B. | succinic acid |
C. | citric acid |
D. | acetyl CoA |
Answer» B. succinic acid | |
133. |
The role of bacteriophyll in an oxygenic photosynthesis is to |
A. | reduce ferridoxin directly |
B. | reduce NADP directly |
C. | use light energy to energize an electron |
D. | transfer electrons to an intermediate in the sulfide oxidation pathway |
Answer» D. transfer electrons to an intermediate in the sulfide oxidation pathway | |
134. |
In photosynthesis by green plants, algae, cyanobacteria which of the following acts as terminal electron acceptor? |
A. | Water |
B. | Oxygen |
C. | NADP+ |
D. | FAD+ |
Answer» D. FAD+ | |
135. |
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. | |
136. |
Which force drives the flagellar rotation in bacteria? |
A. | ATP |
B. | protonmotive force |
C. | electrons |
D. | water gradient |
Answer» C. electrons | |
137. |
The final product of Calvin cycle is _________ |
A. | RuBP |
B. | Glucose |
C. | Dihydroxy acetone phosphate |
D. | Glyceraldehyde-3-phosphate |
Answer» E. | |
138. |
The dark reaction in photosynthesis is governed by __________ |
A. | CO2, temperature, and light |
B. | CO2, light, and water |
C. | water, temperature, and CO2 |
D. | oxygen, water, and temperature |
Answer» B. CO2, light, and water | |
139. |
Which of the following has no detectable ATPase activity? |
A. | cilia |
B. | eukaryotic flagella |
C. | bacterial flagella |
D. | endoflagella |
Answer» D. endoflagella | |
140. |
Which of the following steps during electron transfer in anoxygenic photosynthesis is the ATP production step? |
A. | Ferredoxin to ubiquinone |
B. | ubiquinone to cyt b |
C. | cyt b to cyt f |
D. | cyt f to excited bacteriochlorophyll |
Answer» D. cyt f to excited bacteriochlorophyll | |
141. |
Which pathway will result in the production of four carbon dioxide molecules, two ATP molecules, NADH2 and FADH2? |
A. | glycolysis |
B. | Krebs cycle |
C. | Calvin cycle |
D. | electron transport system |
Answer» C. Calvin cycle | |
142. |
For each glucose molecule broken down, there are______________number of reduced coenzymes to be oxidized. |
A. | 12 |
B. | 8 |
C. | 6 |
D. | 4 |
Answer» B. 8 | |
143. |
Hexose monophosphate pathway is also known as |
A. | phosphogluconate pathway |
B. | oxaloacetate pathway |
C. | malate pathway |
D. | fumerate pathway |
Answer» B. oxaloacetate pathway | |
144. |
Entner - Doudoroff pathway is not found in |
A. | aerobic prokaryotes |
B. | anaerobic prokaryotes |
C. | Both (a) and (b) |
D. | eukaryotes |
Answer» E. | |
145. |
Which of the following enzyme removes the RNA primer with its 5’-nuclease activity? |
A. | DNA polymerase I |
B. | DNA polymerase II |
C. | DNA polymerase III |
D. | RNA polymerase |
Answer» B. DNA polymerase II | |
146. |
Aerobic catabolism of glucose yields how much energy (ATP synthesized) relative to glucose fermentation? |
A. | Slightly less |
B. | About the same |
C. | Twice as much |
D. | More than 10 times as much |
Answer» E. | |
147. |
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 | |
148. |
How many molecules of glucose-6-phosphate are regenerated in pentose-phosphate pathway? |
A. | 3 |
B. | 2 |
C. | 5 |
D. | 4 |
Answer» D. 4 | |
149. |
Which one of the following is produced in the greatest numbers during one turn of the Krebs cycle? |
A. | NADH |
B. | Acetyl-CoA |
C. | FADH2 |
D. | ATP |
Answer» B. Acetyl-CoA | |
150. |
The specific enzyme/(s) of the glyoxylate cycle is/are |
A. | isocitrate lyase |
B. | malate synthase |
C. | both (a) and (b) |
D. | anaplerotic |
Answer» D. anaplerotic | |