Explore topic-wise MCQs in Life Sciences.

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.

151.

Which of the following does not produce oxygen as a product of photosynthesis?

A. Oak trees
B. Purple sulfur bacteria
C. Cyanobacteria
D. Phytoplankton
Answer» C. Cyanobacteria
152.

The following code codes for which of the amino acid respectively?AUG and GUG

A. Phenylalanine,tyrosine
B. Methionine,valine
C. Methionine,alanine
D. Lysine,valine
Answer» C. Methionine,alanine
153.

The bacteriochlorophylls used by the anoxygenic bacteria have absorbance maxima located in the_____portion(s) of the spectrum.

A. green
B. blue
C. ultraviolet
D. infrared
Answer» E.
154.

In order to get inorganic phosphorous into organic compounds, the phosphate ion is incorporated via

A. substrate level phosphorylation
B. oxidative phosphorylation
C. both (a) and (b)
D. DNA
Answer» D. DNA
155.

All are true about Bile, but

A. contain enzymes
B. very quickly digests food
C. is secreted by small intestine
D. is acidic in nature
Answer» B. very quickly digests food
156.

ATP dependent NADPH2 production is a process found in ______________

A. Nitrosomonas
B. Nitrobacter
C. Rhizobium
D. E.coli
Answer» C. Rhizobium
157.

Each turn of Calvin cycle results in the fixation of ________ molecule of carbon dioxide.

A. one
B. two
C. four
D. six
Answer» B. two
158.

Which of the following acts as a precursor for the activation of peptidoglycan?

A. TP
B. UDP
C. NADPH
D. GTP
Answer» C. NADPH
159.

Bactoprenol is a ___________

A. membrane phospholipid
B. amino acid carrier
C. fatty acid
D. enzyme
Answer» B. amino acid carrier
160.

Electrons entering the respiratory chain of chemoautotrophic bacteria enter the chain at higher potential.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
161.

The entry of glycerol into the bacterial cells is by ____________

A. passive diffusion
B. facilitated diffusion
C. group translocation
D. active diffusion
Answer» C. group translocation
162.

Porter or permease is located in the _______________

A. cytoplasmic membrane
B. cell membrane
C. nuclear membrane
D. outer membrane
Answer» B. cell membrane
163.

Facilitated diffusion does not require metabolic energy.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
164.

Rotary motor of flagella is associated with _________

A. M ring
B. P ring
C. L ring
D. M and S ring
Answer» E.
165.

Passive diffusion requires the use of membrane transport proteins for the transport of solute molecules across the membrane.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
166.

The reaction for the transfer of phosphoryl group of phosphoenol pyruvate to the sugar molecule requires which ion?

A. Mg^2+
B. Fe^2+
C. O
D. PO4^2-
Answer» B. Fe^2+
167.

HPr stands for ______________

A. heat-stable carrier protein
B. hydrogen carrier protein
C. pyruvate dehydrogenase
D. high-energy protein
Answer» B. hydrogen carrier protein
168.

Mannitol enzyme II has been purified from _____________

A. E.coli
B. Salmonella typhimurium
C. Saccharomyces cerevisiae
D. Lactobacillus
Answer» B. Salmonella typhimurium
169.

In phosphotransferase system(PTS), the sugar-phosphate is released inside the cell by which of the following?

A. Enzyme I
B. Enzyme II
C. Enzyme III
D. HPr
Answer» C. Enzyme III
170.

The biosynthesis of proline takes place from ____________

A. aspartic acid
B. glutamic acid
C. pyruvic acid
D. alpha-keto glutaric acid
Answer» C. pyruvic acid
171.

Indigestion, Bile pigments can

A. removed with feces
B. permanently stored in gall bladder
C. contains enzymes
D. absorbed by large intestine
Answer» B. permanently stored in gall bladder
172.

The step where glyceraldehyde-3-phosphate is oxidized is a substrate-level phosphorylation.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
173.

The catabolic reaction, pentose-phosphate exists in

A. prokaryotic cells
B. eukaryotic cells
C. prokaryotic and eukaryotic cells both
D. none of these
Answer» D. none of these
174.

Which of the following is responsible for the initiation of RNA polymerase activity?

A. initiation site
B. promoter region
C. sigma factor
D. rho factor
Answer» D. rho factor
175.

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
176.

Purple Sulphur Bacteria contains bacteriochlorophyll b and bacteriochlorophyll c.

A. True
B. False
C. May be
D. Can't say
Answer» C. May be
177.

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
178.

Which of the following is the most complete definition of fermentation?

A. Oxidation of glucose with organic molecules serving as electron acceptors
B. Complete catabolism of glucose to CO2 and HO2
C. Production of energy by substrate-level phosphorylation
D. Production of ethyl alcohol from glucose
Answer» B. Complete catabolism of glucose to CO2 and HO2
179.

The activation of amino acids require energy.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
180.

Persons lower metabolic rate may be due to

A. the fact that he is a child
B. decrease in saliva amylase
C. the fact the he lives in tropic climate
D. low production of thyroxin
Answer» E.
181.

Phosphate deregulated mutants are

A. less sensitive to phosphate regulation
B. moderately sensitive to phosphate regulation
C. highly sensitive to phosphate regulation
D. none of these
Answer» B. moderately sensitive to phosphate regulation
182.

The terminal sequence of nucleotides in all tRNA is __________

A. ACC
B. UGC
C. UCC
D. AGC
Answer» B. UGC
183.

In DNA molecule, the amount of purines is equal to the amount of pyrimidines.

A. True
B. False
C. May be
D. Can't say
Answer» B. False
184.

RuBisCO enzyme plays an important role in __________

A. light phase
B. dark phase
C. electron transport chain
D. TCA cycle
Answer» C. electron transport chain
185.

The glyoxylate cycle is used by some microorganisms when___________ is the sole carbon source.

A. acetate
B. nitrate
C. carbon dioxide
D. all of these
Answer» B. nitrate
186.

If ΔG of a chemical reaction is positive in value and keq is less than 1 then the chemical reaction will

A. proceed in reverse direction
B. proceeed in forward direction
C. not take place in any of the direction
D. none of these
Answer» B. proceeed in forward direction
187.

The number of ATP molecules generated in TCA cycle is _________

A. 34
B. 38
C. 24
D. 12
Answer» D. 12
188.

TCA cycle functions in

A. catabolic reactions
B. anabolic reactions
C. amphibolic reactions
D. none of these
Answer» D. none of these
189.

Basal metabolism, physical activity and heat- all collectively determine the

A. energy intake
B. energy expenditures
C. energy in heart beat
D. energy required to stay emotionally well
Answer» C. energy in heart beat
190.

Basal metabolic rate of a child is than an old person.

A. higher
B. lower
C. exactly same
D. approximately same
Answer» B. lower
191.

The prosthetic group of a cytochrome contains how many iron atoms?

A. one
B. two
C. three
D. four
Answer» B. two
192.

Among the following which can directly react with oxygen?

A. cytochrome c
B. cytochrome c1
C. cytochrome a
D. cytochrome a3
Answer» E.
193.

How many ATP molecules are formed for per molecule of FADH2 reoxidized?

A. 3
B. 1
C. 2
D. 4
Answer» D. 4
194.

Glycolysis can occur in ___________

A. aerobic cells
B. anaerobic cells
C. both aerobic and anaerobic cells
D. neither aerobic and anaerobic cells
Answer» D. neither aerobic and anaerobic cells
195.

The respiratory chain of bacteria is associated with the _____________

A. miitochondrial membrane
B. cytoplasmic membrane
C. cell wall
D. cytoplasm
Answer» C. cell wall
196.

NAME_THE_INHIBITION_WHERE_END_PRODUCTS_OF_BIOSYNTHESIS_PATHWAY_INHIBIT_THE_ACTIVITY_OF_THE_FIRST_ENZYME??$

A. Feedback inhibition
B. Feedback repression
C. Allosteric inhibition
D. Competitive inhibition
Answer» B. Feedback repression
197.

In which of the following phenomenon the end product act as co-repressor and repress the synthesis of metabolic enzymes?$

A. Allosteric regulation
B. Feedback repression
C. Feedback inhibition
D. Regulation by phosphorylation
Answer» C. Feedback inhibition
198.

Which of the following is not an enzyme-catalyzed reaction in metabolism?

A. Isomerization and elimination
B. Internal rearrangement
C. Maillard reaction
D. Free radical reaction
Answer» D. Free radical reaction
199.

Regulation of metabolic pathway is done by following ways except one, mark the one?

A. Substrate concentration
B. Allosteric regulation of enzymes
C. Availability of oxygen
D. Extracellular signals i.e. hormones or growth factors
Answer» D. Extracellular signals i.e. hormones or growth factors
200.

Mark the INCORRECT statement about metabolic pathway.

A. They show the irreversible pathway
B. Each one of them has first committed step
C. They follow the only oxidative process
D. They are regulated
Answer» D. They are regulated