Category: Cell Biology Objective Questions

Cell Biology Multiple Choice Questions on “Extracellular Matrix and Cell Interactions – Cell Walls”.

1. Who discovered cell wall?
A. Karl Rudolphi
B. Boveri
C. J Rhodin
D. Van Beneden
Answer: A
Clarification: Robert Hooke in the year 1665 observed a component of cell called the “wall” which surrounds the cell. Karl Rudolphi and JHF Link found the component independent cell wall in the year 1804.

2. What organism lacks cell wall?
A. Plant cells
B. Protozoa
C. Bacterial cells
D. Algae
Answer: B
Clarification: The animal cells and the protozoa lacks cell wall. They only contain cell membrane followed by the cytoplasm. Because of this they do not have a rigid shape.

3. Bacteria can be divided into classes namely gram-positive bacteria and gram-negative bacteria based on their cell wall.
A. True
B. False
Answer: A
Clarification: The bacteria are divided into gram positive and negative bacteria based on the thickness of the peptidoglycan present in their cell wall. The thick peptidoglycan layer is gram-positive cell wall and thin layer of peptidoglycan is gram-negative cell wall.

4. Which component is present in the cell wall of fungi?
A. Cellulose
B. Hemicellulose
C. Chitin
D. Pectin
Answer: C
Clarification: The fungi have a cell wall made of chitin, which is a glycosamine polymer. Chitin has similar functions with the protein keratin. It is structurally similar to the polysaccharide cellulose.

5. What is S- layer?
A. Solid layer
B. Surface layer
C. Secondary layer
D. Soluble layer
Answer: B
Clarification: The S-layer is otherwise known as a surface layer. It is present in the cell wall of most of the archaea bacteria. This layer is composed of proteins and glycoproteins. They are about a thickness of 5 to 25nm.

6. The cell wall of diatoms composed of __________
A. Biogenic alumina
B. Biogenic ammonia
C. Biogenic silica
D. Biogenic magnesia
Answer: C
Clarification: The cell walls of marine diatoms have biogenic silica which is otherwise known as biogenic opal. This is found as small scales, granules or other geometric structures on the cell wall. This biogenic silica is a major contribution to the global carbon cycle.

7. Which of the following bacteria lacks cell wall?
A. Mycoplasma pneumoniae
B. Bacillus subtilis
C. Staphylococcus aureus
D. Helicobacter pylori
Answer: A
Clarification: Mycoplasma is a genus of bacteria that does not have a distinct cell wall over their cell membrane. Even though these bacteria lack cell wall, they can effectively protect themselves against antibiotics which have a mode of action of inhibiting cell wall synthesis.

8. What is present in the cell wall of Mycobacterium tuberculosis?
A. Cellulose
B. Nitric acid
C. Acetone
D. Mycolic acid
Answer: D
Clarification: Mycolic acid is present in the cell wall of Mycobacterium tuberculosis. It was first isolated from this species in the year 1938 by Stodola et al. Mycolic acid helps this organism to prevent itself from chemical attacks and dehydration.

9. Which of the following antibiotics have their mode of action of inhibition of cell wall synthesis?
A. Nalidixic acid
B. Ciprofloxacin
C. β-lactams
D. Norfloxacin
Answer: C
Clarification: β-lactams is one of the antibiotics, which helps in destroying the bacteria by the inhibition of cell wall synthesis. This helps in the prevention of peptidoglycan synthesis.

10. Which of the following cell wall component can effectively defend against lysozyme?
A. Peptidoglycan
B. Pseudomurein
C. Chitin
D. Biogenic opal
Answer: B
Clarification: Pseudomurein otherwise known as pseudopeptidoglycan is one of the cell wall components of archaea bacteria. They resemble peptidoglycan layer in function and structure but differ in chemical composition. Lysozyme is a defense mechanism in higher animals and they cannot defend against bacteria containing pseudomurein cell wall.

Cell Biology Multiple Choice Questions on “Two Fundamentally Different Classes of Cells – 1”.

1. The genetic material of a prokaryote is present in the ______________
A. Nucleus
B. Cytoplasm
C. Nucleoid
D. Plasmid
Answer: C
Clarification: Bacteria does not contain a true nucleus. Nucleoid is a poorly demarcated region of the cell that contains the bacterial genetic material or bacterial DNA.

2. Which of the following is not true for both prokaryotic and eukaryotic cells?
A. Same composition of plasma membrane
B. Both contain shared metabolic pathways
C. Genetic information encoded in DNA with similar genetic code
D. Both contain Golgi apparatus for protein trafficking
Answer: D
Clarification: Prokaryotic cells do not have organelles such as Golgi Apparatus. However, the composition of plasma membrane is the same. The metabolic pathways such as TCA cycle and glycolysis take place in both. Both contain DNA as the genetic material.

3. Which of the following is present in both prokaryotic and eukaryotic cells?
A. Proteasomes
B. Plasmids
C. Lysosomes
D. Peroxisomes
Answer: A
Clarification: Proteasomes and protein digesting structures present in both archaebacteria and eukaryotes. Proteasomes degrade unnecessary and damaged proteins by proteolysis. Plasmids are double stranded circular DNA found in prokaryotes whereas lysosomes and peroxisomes are only found in eukaryotes.

4. Which of the following polysaccharide is not present in the eukaryotic plant cell wall?
A. Cellulose
B. Chitin
C. Hemicellulose
D. Pectin
Answer: A
Clarification: Chitin is a polysaccharide that is present mainly in exoskeletons of Arthropods and are not a component of plant cell wall. Plant cell wall is majorly composed of cellulose, hemicelluloses and pectin.

5. Pseudopeptidoglycan is a found in the cell wall of _______________
A. Fungi
B. Archaea
C. Bacteria
D. Protozoa
Answer: b
Clarification: Pseudopeptidoglycan is a cell wall component of some Archaea. It differs from bacterial peptidoglycan in chemical composition but has similar physical structure and function as that of bacterial peptidoglycan.

6. Biofilms are ________________
A. Thin polymeric films made of biopolymer
B. Strings of protein filaments
C. Complex, multispecies communities
D. A metabolic product for prokaryotic organisms
Answer: C
Clarification: Prokaryotes such as bacteria were initially thought to be solitary creatures, but they are capable of living as complex communities called as biofilms. A biofilm is defined as a group of microorganisms in which cells stick or adhere to a living or non-living surface. These adherent cells become embedded within a slimy extracellular matrix composed of extracellular polymeric substances (EPS).

7. Escherichia coli commonly inhabit the _______________ place.
A. Human endodermal layer
B. Human digestive tract
C. Human bronchioles
D. Human skin surface
Answer: B
Clarification: Escherichia coli or E.coli is a Gram negative, facultatively anaerobic, rod-shaped bacteria. It mainly inhabits the human digestive tract and is commonly found in the lower intestinal regions of warm-blooded animals such as humans.

8. How many basal body rings do Gram positive bacteria have in the flagella?
A. 2
B. 3
C. 4
D. 1
Answer: A
Clarification: Gram positive bacteria have 2 basal rings in the flagella, one in the peptidoglycan layer and one in the plasma membrane. Gram negative bacteria have 4 basal rings in their flagella. The L ring is located in the plane in the outer membrane, P ring in the plane of peptidoglycan around flagellar rod, MS ring that is located within and above cytoplasmic membrane and C ring extends into the cytoplasm.

9. The rotary engine made of protein at the base of the flagella is driven by ______________
A. Vanderwaal’s foce
B. Proton- motive force
C. Electron passage
D. Exchange of sodium and potassium ions
Answer: B
Clarification: Proton motive force is the flow of protons or hydrogen ions across the bacterial cell membrane due to a concentration gradient set up by cell’s metabolism. This force drives the motor engine at the base of the flagella and helps in flagellar movement.

Cell Biology Multiple Choice Questions & Answers (MCQs)on “Genes, Chromosomes and Genomes – 1”.

1. The segregation of alleles on one trait did not have any effect on the segregation of alleles on a different trait. This is based on ____________
A. Mendel’s law of Heredity
B. Mendel’s law of Dominance
C. Mendel’s law of Independent Assortment
D. Mendel’s law of Segregation
Answer: C
Clarification: There are three Mendel’s laws n Heredity. 1. The Mendel’s law of Dominance states that when a dominant individual is crossed with a recessive individual, the F1 generation offspring will exhibit the dominant trait. 2. According to Mendel’s law of Segregation, a pair of allele governing a single trait segregates from each other during the formation of gametes. 3. According to Mendel’s law of Independent Assortment, the segregation of alleles on one trait did not have any effect on the segregation of alleles on a different trait.

2. Genes that show tendency to be inherited together is known as ____________
A. Linkage group
B. Homologous group
C. Co-dependent genes
D. None of the mentioned
Answer: A
Clarification: Some genes are packed together on a chromosome and tend to pass on from parents to offsprings as a group. These genes form a unit during the formation of gametes and are not separated during gamete formation. These genes on the same chromosome act like they are linked to one another and hence, are known as linkage groups.

3. Giant polytene chromosomes are found in ___________
A. Egg of fruit fly
B. Salivary gland of larvae of fruit fly
C. Salivary gland of adult fruit fly
D. All of the mentioned
Answer: B
Clarification: Polytene chromosomes are a type of giant chromosomes which are many times longer in length than normal chromosomes. Polytene chromosomes are found in the salivary gland of a larval fruit fly and show several distinct darkly stained bands.

4. An example of co-dominance is ____________
A. Mouse coat colour
B. Human ABO blood group system
C. Human hand size
D. Human eye colour
Answer: B
Clarification: When two different alleles are crosses and neither of them is dominant and recessive and both get expressed in the phenotype offspring, then such a genetic scenario is known as codominance. In the ABO Blood group system of humans, a person with A protein has blood type A and a person with B protein has blood type B. If a person with blood type A mates with person with blood type B, then the dominant A and B genes will be co-expressed in the offspring and he will have blood type ‘AB’.

5. Loops in lampbrush chromosomes represent site of _____________
A. Replication
B. Transcription
C. Cell division
D. Crossing over
Answer: b
Clarification: Lampbrush chromosomes are a type of giant chromosomes found in the growing oocytes of amphibians. Twin loops arise on either side of the chromosome in meiotic prophase. This is due to the active transcription of many genes.

6. How can it be determined whether the parent progeny is homozygous or heterozygous?
A. Test cross
B. Back cross
C. Monohybrid cross
D. Reciprocal cross
Answer: A
Clarification: Test cross is the cross of a F1 generation offspring with the homozygous recessive parent. If the offspring phenotype is dominant: recessive = 1:1, the F1 offspring is heterozygous dominant. If all the plant exhibits dominant phenotype, the F1 offspring is homozygous dominant. In this way, the genotype of an offspring can be determined.

7. The expression of Holandric genes causes the following genetic trait ______________
A. Haemophilia
B. Colour blindness
C. Down’s syndrome
D. Hypertrichosis
Answer: D
Clarification: Y-linked genes are called Holandric genes. Hypertrichosis is the genetic trait by which hair appears on the earlobe of an individual. The gene for Hypertrochosis is present in the Y chromosome and thus this trait is only expressed in males. This trait is governed by holandric gene.

8. The method of DNA replication is _____________
A. conservative
B. semi-conservative
C. non-conservative
D. disruptive
Answer: B
Clarification: In DNA replication , the two daughter strands unwind and are used as template for the formation of a new DNA strand. As a result, one strand in conserved and a new strand is produced by taking the conserved strand as a template. Thus, DNA replication is a semi-conservative process.

9. The DNA binding proteins bind at the _______________
A. Minor groove
B. Major groove
C. Phosphate molecules
D. Pentose sugars
Answer: B
Clarification: The DNA double strands are present as a double-helix as they wound around each another. Due to base stacking, alternative minor and major grooves are formed in the helix. Major groove provide the site for DNA protein binding.

10. During DNA denaturation, which of the following occurs?
A. Unwinding of DNA double strand
B. Absorbance of UV rays
C. Decrease in hydrophobic interactions of base stacking
D. All of the mentioned
Answer: D
Clarification: DNA denaturation takes place either due to thermal treatment or due to treatment in saline solution. During denaturation, DNA double strands get separated and there is an increase in the absorbance of UV rays by the dissolved DNA. Once the two DNA strands have separated, the hydrophobic interactions that result from base stacking are greatly decreased.

11. Human Genome Project was focused on discovering the details of ___________
A. sNRPs
B. 3D DNA structure
C. Junk DNA
D. VNTRs
Answer: C
Clarification: The Human Genome Project was an international scientific research project with the goal of determining the sequence of nucleotide base pairs that make up human DNA from a period of 1990 to 2003. The main purpose of these projects was to find out the base sequence of human junk DNA which was different for every individual.

Cell Biology Problemson “Mitochondrial Structure and Function – 2”.

1. Glycolysis takes place in _____
A. Outer membrane of mitochondria
B. Inner membrane of mitochondria
C. Mitochondrial matrix
D. Cytosol
Answer: D
Clarification: The process of cellular respiration involves the following steps- Glycolysis, Kreb’s cycle and electron oxidation. The Glycolysis stage occurs in cytoplasm and the Kreb’s cycle occurs in the matrix of mitochondria.

2. The first stable compound of Kreb’s cycle is _____________
A. Citrate
B. Cis- Aconitate
C. Oxaloacetate
D. Malate
Answer: A
Clarification: Kreb’s cycle has Citrate as its first stable compound. That is why it is also called Citric Acid Cycle. Citrate is a compound containing three carboxylic acid groups and it is thus also called Tricarboxylic Acid cycle or TCA cycle.

3. How many ATP molecules are produced per glucose molecules in eukaryotic Glycolysis?
A. 2 ATP
B. 3 ATP
C. 4 ATP
D. 6 ATP
Answer: A
Clarification: The process of cellular respiration involves the following steps- Glycolysis, Kreb’s cycle and electron oxidation, which are involved in energy production by utilizing carbohydrate. Energy is produced in the form of Adenosine triphosphate (ATP) molecules with 2 ATP molecules produced per glucose molecule in Glycolysis.

4. How many ATP molecules are produced per Krebs’ Cycle in eukaryotes?
A. 2 ATP
B. 36 ATP
C. 38 ATP
D. 24 ATP
Answer: D
Clarification: A total of 6 NADH, 2 ATP, and 2 FADH2 molecules are being produced. 3 ATP molecules are produced per NADH molecules. Thus, 18 (6X3) ATP molecules are produced as Krebs’ cycle produces 6 NADH molecules. 1 FADH2 molecule produces 2 ATP, so for 2 FADH2 molecules, 4 ATP molecules are produced. 2 GTP molecules equivalents to 2 ATP molecules produced in Krebs’ cycle. Thus, in one Krebs’ cycle, (18+4+2) = 24 molecules of ATP are produced.

5. After glycolysis, which of the following is transported across the inner mitochondrial membrane into the matrix?
A. Pyruvate
B. Acetyl CoA
C. ATP molecules
D. Coenzyme A
Answer: A
Clarification: Each pyruvate molecule produced in cytosol during Glycolysis is transported across the inner mitochondrial membrane into the mitochondrial matrix. Pyruvate is then decarboxylated to produce Acetyl group (CH₃COO^–) The Acetyl group is transferred to Coenzyme A to produce acetyl CoA.

6. The TCA cycle produces ____________
A. 2 NADH
B. 6 NADH
C. 8 NADH
D. 4 NADH
Answer: B
Clarification: The primary products of the TCA cycle pathway are the reduced coenzymes, NADH and FADH₂, which contain high energy electrons removed from various substrates as they are oxidized. A total of 6 NADH are formed during one Krebs’ cycle process.

7. The TCA cycle produces _____________
A. 2 FADH₂
B. 3 FADH₂
C. 4 FADH₂
D. 1 FADH₂
Answer: A
Clarification: The primary products of the TCA cycle pathway are the reduced coenzymes, NADH and FADH₂, which contain high energy electrons removed from various substrates as they are oxidized. A total of 2 FADH₂ are formed during one Krebs’ cycle process.

8. The TCA cycle produces ___________
A. 2 GTPs
B. 1 GTP
C. 3 GTPs
D. 4 GTPs
Answer: A
Clarification: The primary products of the TCA cycle pathway are the reduced coenzymes, NADH and FADH₂, which contain high energy electrons removed from various substrates as they are oxidized. The Krebs’ cycle produces two GTP molecules during one cycle. 2 GTP molecules equivalents to 2 ATP molecules.

9. In the electron transport chain, each pair of electron transferred from NADH to oxygen releases sufficient energy to produce __________
A. 3 ATPs
B. 1 ATP
C. 2 ATPs
D. 4 ATPs
Answer: A
Clarification: Electron is transported from the reduced cofactor NADH to oxygen by electron transport chain. During the transfer, it releases sufficient energy to drive the formation of approximately 3 ATP molecules.

10. In the electron transport chain, each pair of electron donated by FADH2 releases sufficient energy to produce __________
A. 3 ATPs
B. 1 ATP
C. 2 ATPs
D. 4 ATPs
Answer: C
Clarification: Electron is donated by the reduced cofactor FADH₂ to oxygen by electron transport chain. During the transfer, it releases sufficient energy to drive the formation of approximately 2 ATP molecules.

11. Total number of ATPs formed by oxidation of one glucose molecule is ___________
A. 36 ATPs
B. 30 ATP
C. 32 ATPs
D. 34 ATPs
Answer: A
Clarification: For oxidation of one glucose molecules, 2 ATP molecules are produced by glycolysis. 24 ATP molecules are produced by Kreb’s cycle and 10 ATP molecules is produced by electron oxidative chain. This adds up to 36 molecules ATP released by oxidation of one molecule of glucose.

12. Which of the following is not involved in electron chain transport system?
A. Complexes I, II, II, IV
B. Ubiquinone
C. Cytochrome C
D. All of them are involved
Answer: D
Clarification: Electron carriers can be isolated as part of four distinct, asymmetric, membrane-spanning complexes known as complexes I, II, II and IV. Two of the electron transport chain complexes, Ubiquinone and Cytochrome C are not part of any complexes. Ubiquinone is present as a pool of molecules dissolved in lipid bilayer and Cyt C is soluble protein in intermembrane space.

13. NADH and FADH₂ is associated with respectively ____________
A. Complexes I and complex II
B. Complexes II and complex III
C. Complexes I and complex III
D. Complexes III and complex IV
Answer: A
Clarification: When NADH is the electron donor, electrons enter the respiratory chain via complex I, which transfers electrons to Ubiquinone. FADH₂ remains covalently attached to succinate dehydrogenase, a component of complex II. When FADH₂ is donor, electron is directly passed to Ubiquinone.

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Cell Biology Multiple Choice Questions on “Cytoplasmic Membrane Systems – Endomembrane System”.

1. Which of the following together represent an endomembrane system?
A. macromolecules of the cell
B. cell receptors
C. cytoplasmic structures
D. nuclear structures
Answer: C
Clarification: The cytoplasmic organelles of a cell namely endoplasmic reticulum, Golgi complex, lysosomes, vacuoles; together represent the endomembrane system where individual components function as a part of a coordinated unit.

2. Organelles of the endomembrane system are stable and static.
A. True
B. False
Answer: B
Clarification: Organelles of the endomembrane system are dynamic in nature and experience a continuous flux while they perform the regular activities inside the cell.

3. Proteins are synthesized in which of the following organelle of the endomembrane system?
A. Endoplasmic reticulum
B. Golgi complex
C. Lysosomes
D. Vacuoles
Answer: A
Clarification: Proteins are synthesized in the endoplasmic reticulum and then modified in the Golgi complex. From the Golgi complex, the proteins are further transported to different destinations depending upon their function and fate.

4. There are ______ types of secretory activities of a cell.
A. one
B. two
C. three
D. four
Answer: B
Clarification: Secretory activities lead to the discharge of proteins synthesized in the endoplasmic reticulum. There two types of secretory activities of a cell namely constitutive secretion and regulated secretion.

5. In regulated secretion, materials are __________
A. secreted
B. stored
C. degraded
D. aggregated
Answer: B
Clarification: In regulated secretion activities of the cell, materials are stored in membrane bound packages and released only when there is an invoked response.

6. Which type of endomembrane secretion occurs in nerve cells?
A. constitutive
B. regulatory
C. non-continuous
D. intermittent
Answer: B
Clarification: The nerve cells secrete neurotransmitters in response to an extracellular stimulus, the secretion is therefore termed as regulatory secretion.

7. What of the following molecules is not transported through the secretory pathway of endomembrane system?
A. nucleic acids
B. complex polysaccharides
C. proteins
D. lipids
Answer: A
Clarification: In the secretory pathway or the biosynthetic pathway biomolecules like proteins, lipids and complex polysaccharides are transported across the cell.

8. In the endocytic pathway, materials are discharged from the cell.
A. True
B. False
Answer: B
Clarification: Endocytic pathway is the opposite of secretory pathway. In the endocytic pathway materials move from the outer surface of the cell to the cytoplasmic compartments like endosomes and lysosomes.

9. Which of the following biomolecules are contained in the lysosomes?
A. nucleic acids
B. ribonucleic acids
C. proteins
D. polysaccharides
Answer: C
Clarification: The lysosomes play a vital role in digestion and waste removal from the cell. These organelles are composed of soluble proteins that carry out this function.

10. Which type of signals direct the proteins to their appropriate cellular destinations?
A. sorting signals
B. apoptotic signals
C. ubiquitylation
D. degradation signals
Answer: A
Clarification: Sorting signals encoded in amino acid sequence of proteins or in the attached sugar molecules are responsible for directing the proteins to their appropriate cellular destinations.

Cell Biology Interview Questions and Answerson “Two Fundamentally Different Classes of Cells – 2”.

1. Escherichia coli and Vibrio cholerae are ________________
A. lophotrichous; monotrichous
B. amphitrichous; lophotrichous
C. peritrichous; monotrichous
D. peritrichous; amphitrichous
Answer: C
Clarification: Monotrichous bacteria have single flagellum (eg. Vibrio cholerae). Lophotrichous bacteria have multiple flagella in same spot which helps in unidirectional movement. Peritrichous bacteria (eg. E.coli) has flagella projecting in all directions. Amphitrichous bacteria have single flagellum on opposite ends.

2. Nitrogen fixation can be done by ______________
A. All prokaryotes
B. Certain cyanobacteria
C. Certain archaebacteria
D. None of the mentioned
Answer: B
Clarification: Certain cyanobacteria have the unique property to fix nitrogen i.e., conversion of nitrogen gas into reduced ammonia. Certain cyanobacteria remain in a symbiotic relationship in the roots of legume plants such as peas and help in nitrogen fixation. Eg. Rhizobium, Azotobacter, etc.

3. F-plasmid contains ______________
A. Only OriV
B. Only OriT
C. Both OriV and OriT
D. None of the mentioned
Answer: C
Clarification: The F-plasmid is an episome formed during bacterial conjugation. It contains its own origin of replication called as ‘OriV’ and Origin of transfer called as ‘OriT’.

4. Which is the main building block of cilia?
A. Tubulin
B. Nexin
C. Dyenin
D. Actin
Answer: A
Clarification: Tubulin proteins are the main building blocks of cilia in prokaryotic organisms. Dyenin forms bridges between neighbouring microtubule doublets in structure of cilia. Nexin is present between microtubule doublets and prevent them to slide over one another.

5. Which of the following is not a difference between cilia and flagella?
A. Cilia is short hairlike; flagella is long thread-like
B. Nexin present in cilia; Nexin absent in flagella
C. Axoneme present in cilia; Axoneme absent in flagella
D. Rapid rotational motion of cilia; Undulating, sinusoidal slow movement of flagella
Answer: C
Clarification: Inside both cilia and flagella, is a microtubule-based cytoskeleton called axoneme. Axoneme is the central strand of either a cilium or flagellum which is composed of an array of microtubules. Microtubules are arranged in nine pairs around two central microtubule (9+2 combination).

6. Which of the following is absent in Gram- negative bacteria and present in Gram- positive bacteria?
A. Teichoic acids
B. Periplasmic space
C. Outer membrane
D. Lipopolysaccharide
Answer: A
Clarification: Teichoic acids are present in Gram positive and absent in Gram negative bacteria and they stain purple by Gram stain. Periplasmic space and outer membrane are present in Gram negative while they are absent in Gram positive bacteria. Lipolysaccharide content is high in Gram negative and almost none in Gram positive.

7. Exotoxins are produced by _______________
A. All prokaryotes
B. Gram positive bacteria
C. Gram negative bacteria
D. Archaea
Answer: B
Clarification: Exotoxins are produced by Gram positive bacteria. Endotoxins are produced by Gram negative bacteria.

8. Which of the following statements is false?
A. Gram negative bacteria is less resistant to physical disruption than Gram positive.
B. Gram positive bacteria is inhibited by basic dyes
C. Gram negative bacteria cell wall is thin and single layered.
D. Gram negative bacteria is more resistant to antibiotics than Gram positive.
Answer: C
Clarification: The cell wall of Gram negative bacteria is thick and two layered. However, the cell wall of Gram positive bacteria is thick and single layered.

9. Which of the following are a Gram negative bacteria?
A. Neisseria gonorrheae
B. Mycoplasma pneumonia
C. Cornybacterium diptheriae
D. Streptococcus pyogenes
Answer: A
Clarification: Neisseria gonorrheae is an example of Gram negative bacteria. However, Mycoplasma pneumonia, Cornybacterium diptheriae, Streptococcus pyogene are some examples of Gram positive bacteria.

To practice all areas of Cell Biology for Interviews,