TOP 200 BIOLOGY MCQS FOR ALL EXAM

CHAPTER CELL STRUCTURE AND FUNCTION

MCQS

1. What is a cell?

a) smallest and advanced unit of life

b) smallest and basic unit of life

c) largest and basic unit of life

d) largest and advanced unit of

Answer: b

Explanation: A cell is the smallest and most

fundamental unit of life, responsible for all of

life’s operations. All living beings have cells that

serve as structural, functional, and biological

units.

2. Which of the following is a functional unit of a

body?

a) Mitochondria

b) Cytoplasm

c) Spleen

d) Cell

Answer: d

Explanation: Because all living beings are made

up of cells, the cell is recognized as the structural

and functional unit of life.

3. What is cell biology?

a) Study of cell division only

b) Study of cancerous cell

c) Study of cell structure and function

d) Study of metaphase of a cell

Answer: c

Explanation: The study of cell structure and

function is known as cell biology, and it is based

on the idea that the cell is the most basic unit of

life. Concentrating on the cell allows for a more

in-depth understanding of the tissues and

organisms that cells make up

4. Which of the following is used by cells to

interact with other cells?

a) Cell tubules

b) Cell junctions

c) Cell adhesions

d) Cell detectors

Answer: b

Explanation: Cell junctions are used by cells to

interact with each other in certain tissues. These

are stable interactions made for the development

and function of the cell.

5. In which of the following type of cells the cell

junction is abundant?

a) Cardiac cells

b) Prokaryotic cells

c) Hepatic cells

d) Epithelial cells

Answer: d

Explanation: The cell junction is abundant in

epithelial cells, which provide barrier and control

over the transport in the cell. It is otherwise

known as intercellular bridge, which is made up

of multiprotein complexes.

6. What is epithelial mesenchymal transistion?

a) Loss of migration and gain of adhesion

b) Formation of mesenchymal cells

c) Loss of adhesion and gain of migration

d) Lysis of cell

Answer: c

Explanation: Epithelial mesenchymal transition is

the property of cells losing adhesion and gaining

migration. It is highly useful in the pluripotency

of stem cells in organ development.

7. In which of the following type of cells the Gap

junctions are absent?

a) Sperm cells

b) Brain cells

c) Reproductive cells

d) Cardiac cells

Answer: a

Explanation: Gap junctions are absent in all the

cell that are motile. Gap junctions are also absent

in erythrocytes. These motile cells do not have a

necessity for the passage of molecules or ions.

8. In which of the following type of cells

Sarcoplasmic reticulum is found?

a) muscle cells

b) liver cells

c) kidney cells

d) neurons

Answer: a

Explanation: Smooth endoplasmic reticulum

sequesters calcium ions within the cytoplasm of

the cell and controlled release of Ca2+ from the

SER of cardiac and skeletal muscle cells triggers

contraction. Smooth endoplasmic reticulum (SER)

in the aforementioned cells is known as

sarcoplasmic reticulum.

9. Which of the following are phagocytic cells?

a) neutrophils, mast cells

b) mast cells, macrophages

c) mast cells, antibodies

d) neutrophils, macrophages

Answer: d

Explanation: Neutrophils and macrophages are

the phagocytic cells that ingest potentially

dangerous microbes; the microbes are then

inactivated by the low pH of lysosomes present in

these cells followed by their enzymatic digestion.

10. Which of the following is known as the

powerhouse of a cell?

a) Mitochondria

b) Cytoplasm

c) Lysosome

d) Nuclei

Answer: a

Explanation: The mitochondria, also known as

the “powerhouse of the cell,” are the organelles

that produce energy within the cell. The

mitochondria are the major site for ATP

generation and play a significant role in cellular

respiration.

11. Which of the following is known as the suicide

bag of a cell?

a) Mitochondria

b) Golgi Complex

c) Lysosome

d) Nuclei

Answer: c

Explanation: The digesting enzymes are found in

lysosomes. When lysosomes rupture, digestive

enzymes are released, which begin digesting the

body’s own cells. That’s why they’re referred to as

suicidal bags.

12. Lysosomes are produced by which of the

following cell organelles?

a) Mitochondria

b) Endoplasmic Reticulum

c) Golgi Complex

d) DNA

Answer: c

Explanation: They are produced by the Golgi body.

The fusion of vesicles from the Golgi complex with

endosomes produces lysosomes.

13. Which of the following cell organelle is

responsible for transporting, modifying, and

packaging proteins and lipids?

a) Mitochondria

b) Endoplasmic Reticulum

c) Golgi Complex

d) DNA

Answer: c

Explanation: The Golgi apparatus, also known as

the Golgi complex, is a factory where proteins

from the ER are further processed and sorted

before being transported to their final

destinations: secretion, lysosomes, or the plasma

membrane.

14. Which of the following cell doesn’t contain a

cell wall?

a) Plant cell

b) Bacteria

c) Fungi

d) Animal cell

Answer: d

Explanation: Plant cells require a cell wall, but

animal cells do not, as plants require a stiff

framework in order to grow up and out. Cell

membranes are present in all cells and are

flexible. Plant cells only have the shapes of their

cell walls, but animal cells can have a variety of

shapes.

15. Who is the father of cell biology?

a) George N. Papanicolaou

b) George Emil Palade

c) Robert Hooke

d) None of the above

Answer: b

Explanation: Dr. George Emil Palade, a Nobel

Laureate, is known as the “Father of Cell Biology”

for his pioneering work in the subject. He was a

pioneer in the use of the electron microscope,

which he used to discover ribosomes and

secretory protein activity.

16. DNA is stored in which of the following cell

organelle?

a) Cell wall

b) Cell Membrane

c) Nucleus

d) Cytoplasm

Answer: c

Explanation: DNA contains the blueprints for all

of the proteins in our bodies, neatly packed in a

double helix. Transcription and translation are

the processes that turn DNA into proteins, and

they take place in distinct parts of the cell. The

first step, transcription, takes place in the

nucleus, which is where the DNA is stored.

17. In which of the following cell nucleus is not

present?

a) Eukaryotic cell

b) Prokaryotic cell

c) Both of the above

d) None of the above

Answer: b

Explanation: Nucleus is absent in prokaryotic

cells. Instead, they have a nucleoid region in the

cell.

18. Which of the following organisms doesn’t have

a cell?

a) Virus

b) Bacteria

c) Fungi

d) Algae

Answer: a

Explanation: Viruses aren’t made up of cells.

Their genetic material is protected by a protein

covering (either DNA or RNA). However, they lack

a cell membrane and other organelles seen in

cells.

19. Who proposed the cell theory?

a) Theodor Schwann, Watson and Robert Hooke

b) Theodor Schwann, Matthias Schleiden and

Robert Hooke

c) Theodor Schwann, Matthias Schleiden and

Rudolf Virchow

d) NTheodor Schwann, Rudolf Virchow and

Robert Hooke

Answer: c

Explanation: Theodor Schwann proposed the

classical cell hypothesis. This hypothesis is

divided into three parts. All organisms are made

up of cells, according to the first section. Cells are

the basic units of life, according to the second

portion. These sections were based on a

conclusion reached by Schwann and Matthias.

20. RNA is present in which of the following cell

organelles?

a) Cell wall

b) Ribosome

c) Nucleus

d) Cytoplasm

d) Golgi complex

Answer: b

Explanation: Ribosomes are tiny organelles that

contain RNA and specific proteins within the

cytoplasm.

21. A cell organelle that is present in animal cells

but not present in plant cells is?

a) Cytoplasm

b) Centrosome

c) Mitochondrial

d) Cytoplasm

d) Golgi complex

Answer: b

Explanation: Plant cells lack a centrosome and

lysosomes, while animal cells do. Animal cells

lack a cell wall, chloroplasts, and other

specialized plastids, as well as a big central

vacuole, but plant cells do.

2. Which of the following cell is found in the

brain?

a) Neuron

b) Hepatocyte

c) Nephron

d) Epithelial cell

Answer: a

Explanation: Hepatocyte is found in the liver. The

nephron is the filtering unit of the kidney.

Epithelial cell lines the surfaces of your body.

3. Protein synthesis takes place in which of the

following cell organelle?

a) Cell wall

b) Ribosome

c) Nucleus

d) Cytoplasm

Answer: b

Explanation: Protein synthesis takes place on

ribonucleoprotein particles called ribosomes in

the cytoplasm. Ribosomes in the cytoplasm

transform mRNA molecules exported from the

nucleus into protein (which are RNA-protein

complexes, not organelles)

4. Which of the following cells are found in the

intestinal lining?

a) RBCs

b) Neurons

c) Epithelial cells

d) Hepatocytes

Answer: c

Explanation: Epithelial cells line the intestine and

are responsible for the uptake and absorption of

nutrients from the digestive tract. Microvilli are

located at the apical end of these cells and

mitochondria are located at the basal end.

5. Which of the following polysaccharide is not

present in the eukaryotic plant cell wall?

a) Chitin

b) Hemicellulose

c) Pectin

d) Cellulose

Answer: d

Explanation: 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.

6. Which of the following is the process of

synthesis of glucose?

a) saccharification

b) glycolysis

c) gluconeogenesis

d) neogenesis

Answer: c

Explanation: The anabolic pathway that leads to

the formation of glucose is referred to as

gluconeogenesis. A cell can synthesize glucose at

the same it as utilizing glucose as the source of

chemical energy.

7. Which of the following site is represented by

Loops in lampbrush chromosomes?

a) Crossing over

b) Cell division

c) Replication

d) Transcription

Answer: d

Explanation: 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 the meiotic prophase.

This is due to the active transcription of many

genes

8. Which of the following part of a neuron receives

information from other neurons?

a) myelin sheath

b) dendrites

c) cell body

d) axon

Answer: b

Explanation: The fine extensions from the cell

body of the neurons are called dendrites which

receive information from external sources,

usually other neighboring neurons.

9. Which of the following is not a component of

cell membranes?

a) Phosphotriglycerides

b) Cholesterol

c) Sphingolipids

d) Phosphodiglycerides

Answer: a

Explanation: Phospholipids present in cell

membrane are diglycerides and not triglycerides.

Triglycerides have three fatty acids and are not

ampipathic in nature. It also consists of

sphingolipid and cholesterol.

10. Which of the following promote curvature of

cell membrane?

a) Phosphatidyl serine (PS)

b) Phosphatidyl inositol(PI)

c) Phosphatidyl choline (PC)

d) Phosphatidyl ethanolamine (PE)

Answer: d

Explanation: PE promotes the curvature of cell

membrane. This is important in the budding and

fusion of cell membranes during maturation

11. Which of the following is not a type of

chromosomal aberration?

a) duplication

b) translocation

c) mutations

d) inversion

Answer: c

Explanation: Chromosomal aberration refers to

the change in number of chromosomes or any

other associated errors. There are various types

of chromosomal aberrations including

inversions, translocations, duplications etc.

Mutation however is a broader term.

12. Which of the following cells release insulin

when glucose levels elevate in the body?

a) gamma cells

b) beta cells

c) alpha cells

d) zeta cells

Answer: b

Explanation: The beta cells in pancreas secrete

insulin when the blood glucose levels elevate while

the alpha cells in the pancreas secrete glucagon

when the blood glucose levels drop. Insulin acts as

an extracellular messenger molecule.

13. Which of the following cells are pluripotent?

a) embryonic stem cells

b) nucleosomes

c) hepatocytes

d) neurons

Answer: a

Explanation: Embryonic stem cells appear very

early in the development of a mammalian embryo

and possess two very unique properties, indefinite

self-renewal and capability of differentiating into

different cell types.

14. Which of the following cells do not lack the

ability to divide?

a) red blood cells

b) muscle cells

c) skin cells

d) nerve cells

Answer: c

Explanation: Only highly specialized cells of the

body such as nerve cells, muscle cells and red

blood cells lack the ability to divide, once they

have differentiated they remain in that state till

the end of their life cycles.

15. Which of the following cells do not usually

divide but can be induced to divide?

a) liver cells

b) red blood cells

c) hair cells

d) hair follicles

Answer: a

Explanation: Liver cells do not usually grow and

divide but can be made to do so under specific

conditions such as liver surgery. Lymphocytes can

also be induced to regrow and divide by

interaction with a proper antigen.

1. Proteome is a ____________

a) A precursor of protein

b) Storehouse of proteins

c) An inventory of the total amount of proteins

d) None of the mentioned

Answer: c

Explanation: The entire inventory of proteins that

is produced by an organism is known as that

organism’s proteome. It may be also applied to the

inventory of proteins in a particular tissue or cell.

Proteomics is the field of protein biochemistry.

2. Which of the following is not a protein

denaturant?

a) SDS

b) Phenol

c) DTT

d) Acetic acid

Answer: d

Explanation: Sodium dodecyl sulfate or SDS is a

strong denaturant of protein and is used in SDS-

PAGE technique. DTT is oftentimes used along

with SDS to further denature proteins by reducing

their disulfide bonds to allow for better

separation of proteins during electrophoresis.

Phenol is used as a protein denaturant during

isolation of RNA from plants.

3. Which of the following is untrue?

a) Protein folding occurs in Golgi bodies

b) Protein folding is assisted by a protein

molecule called Chaperone

c) Transmembrane or organelle proteins contain

a signal peptide

d) Proteins are present in cytoplasm and cell

organelles of all cells

Answer: a

Explanation: The folding of proteins occurs in the

lumen of the Endoplasmic Reticulum (ER). A newly

synthesized protein undergoes a series of

modifications in the ER with the help of a number

of molecular chaperones and folding enzymes

that all together assist its proper folding and

subsequent release from ER. The majority of ER

proteins are dedicated to the folding of proteins.

Golgi bodies help in the proper packaging and

transport of proteins.

4. RNA does not have the nitrogen base of _______

a) Uracil

b) Cytosine

c) Thymine

d) Adenine

Answer: c

Explanation: RNA does not have the pyrimidine

Thymine and has Uracil instead while DNA has

Thymine. In RNA, Adenine binds to Uracil with

two hydrogen bonds while in DNA, Adenine binds

to Thymine by two hydrogen bonds.

5. Which of the following is functionally the odd

one out?

a) siRNA

b) miRNA

c) shRNA

d) snRNA

Answer: d

Explanation: micro RNA (miRNA) is a small non-

coding RNA that helps in gene silencing. Small

interfering RNA (siRNA) helps in gene silencing

through the RNA interference pathway. Short

hairpin RNA (shRNA) silences target gene via RNA

interference. However, small nuclear RNA or

snRNA helps in RNA splicing and processing.

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6. Which of the following RNA is artificially made?

a) snRNA

b) scRNA

c) miRNA

d) siRNA

Answer: b

Explanation: siRNA, snRNA and miRNA are all

produced naturally in the cell. Small cytoplasmic

RNA (scRNA) is an engineered (artificial) RNA

molecule that helps in in-vitro and in-vivo signal

transduction.

7. In RNA transcription, which of the

following is a part of TBP-associated factor (TAF)?

a) TFIID

b) TFIIB

c) TFIIF

d) TFIIH

Answer: a

Explanation: TFIID includes the TBP subunit

which binds to the TATA box along with some

other proteins, together known as the TBP-

associated factors. TFIIB provides a binding site

for RNA Polymerase. TFIIF contains a special

subunit which is bound to the entering RNA

Polymerase. TFIIH contains 10 subunits, 3 of

which possess enzymatic activity.

8. Those part of the DNA or gene that contribute to

the mRNA product is called _________

a) Introns

b) Intervening sequences

c) Exons

d) Split genes

Answer: c

Explanation: Intervening sequences, also called

introns are the portions of DNA excluded during

transcription and thus are not there in the mRNA

product. Exons are the part of DNA transcribed to

form mRNA. The genes with intervening sequences

are called split genes.

9. Which of the following disaccharides have beta

(1->4) bond?

a) Maltose and Sucrose

b) Maltose and Isomaltose

c) Lactose and Cellobiose

d) Sucrose and Cellobiose

Answer: c

Explanation: Among the disaccharides, sucrose,

maltose and isomaltose have alpha(1->4)

glycosidic bond. However, lactose, lactulose and

sucrose have beta(1->4) glycosidic linkage.

10. An example of polar but uncharged amino

acid is ___________

a) Lysine

b) Aspartate

c) Serine

d) Arginine

Answer: c

Explanation: Lysine and Arginine are polar and

positively charged amino acids. While Aspartate

is a polar and negatively charged amino acid.

Serine is a polar and uncharged amino acid.

11. Example of a polar amino acid is ____________

a) Glutamine

b) Alanine

c) Methionine

d) Valine

Answer: a

Explanation: Glutamine is a polar but non-

charged amino acid. Alanine, Valine and

Methionine, on the other hand, are non-polar

amino acids

1. Reactions that lose heat are termed as

_____________

a) endothermic

b) exothermic

c) chemical

d) physical

Answer: b

Explanation: Energy can neither be created nor be

destroyed. It is only transduced from one form

into another. Heat is also a form of energy;

reactions in which heat is lost to the surroundings

are termed as exothermic reactions and those in

which heat is gained from the system are termed

as endothermic reactions

2. According to laws of thermodynamics, the

energy of the Universe is _________ whereas the

entropy ______________

a) constant, increases

b) constant, decreases

c) increases, remains constant

d) decreases, remains constant

Answer: a

Explanation: According to the first and second

laws of thermodynamics, the energy of the

universe remains constant however the entropy

increases owing to the randomness.

3. Exergonic processes are thermodynamically

unfavorable.

a) True

b) False

Answer: b

Explanation: The processes having negative Gibbs

free energy (-ΔG) are termed as exergonic; are

thermodynamically favored and are spontaneous

in nature. Processes having +ΔG are endergonic,

thermodynamically unfavorable and non-

spontaneous.

4. Hydrolysis of ATP is which type of reaction?

a) Physical

b) Mechanical

c) Endergonic

d) Exergonic

Answer: d

Explanation: Hydrolysis of ATP is the most

important chemical reaction in a living cell. It is

highly favorable and exergonic with a standard

free energy (ΔG⁰’) between reactants and

products equal to -7.3 kcal/mol.

5. Cellular metabolism is a non-equilibrium

metabolism.

a) True

b) False

Answer: a

Explanation: Cellular metabolism is essentially a

non-equilibrium metabolism; that is the ratio of

reactants to products is maintained in a non-

equilibrium state. This makes most of the

reactions irreversible

6. Which of the following are responsible virtually

for every reaction that takes place inside a cell?

a) Carbohydrates

b) ADP

c) Nucleic acids

d) Enzymes

Answer: a

Explanation: Enzymes are the catalysts

responsible for virtually everything that takes

place inside a cell. Without these catalysts the

cellular metabolism and bioenergetics would be

imperceptible.

7. Protein catalysts are called __________ and RNA

catalysts are called _____________

a) enzymes, ribozymes

b) ribozymes, enzymes

c) enzymes, ribosomes

d) ribosomes, enzymes

Answer: a

Explanation: RNA catalysts are called ribozymes

whereas protein catalysts are called enzymes.

Most of the catalysts are enzymes made of

proteins.

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8. The non-protein constituents of conjugated

proteins are called ___________

a) enzymes

b) cofactors

c) amino acids

d) nucleosides

Answer: b

Explanation: The non-protein constituents of

conjugated proteins (that act as enzymes) are

called cofactors. These cofactors can be inorganic

metals or organic coenzymes.

9. Enzymes have no effect on which of the

following, in a chemical reaction?

a) activation energy

b) speed

c) thermodynamics

d) completion time

Answer: c

Explanation: Enzymes are responsible for

catalyzing reactions by reducing the activation

energy. However there is no effect on the

thermodynamic aspect of the given reaction.

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10. What will happen if heat is applied to an

enzyme mediated reaction?

a) Rate will increase

b) pH will increase

c) pH will decrease

d) Denaturation of enzyme

Answer: a

Explanation: The rate of an enzymatic reaction

will increase with temperature but only upto a

certain limit. Too much heat energy causes the

enzyme to denature. This rate varies among

different enzymes.

11. Chymotrypsin is a ___________

a) starch

b) polymer

c) buffer

d) enzyme

Answer: d

Explanation: Chymotrypsin is an enzyme that

digests food proteins within the small intestine.

The active site of this enzyme contains partial

positive and partial negative charges.

12. Induced fit in an enzyme refers to

____________________

a) error

b) loop

c) conformational change

d) torsional change

Answer: c

Explanation: Induced fit of an enzyme refers to

the conformational change that arises when a

substrate molecule comes and binds to an

enzyme. As these conformational changes arise,

mechanical work is performed the enzyme exerts

physical force on certain bonds within the

substrate. This has an effect of destabilizing the

enzyme, causing it to adopt a transition state in

which this strain is relieved.

13. Allosteric site is same as enzyme’s active site.

a) True

b) False

Answer: b

Explanation: Allosteric site is spatially different

from enzyme’s active site. It is the site where a

compound can bind and lead to inhibition or

activation of an enzyme.

14. Feedback inhibition is cell’s mechanism to

_____________ the process of anabolism.

a) activate

b) inhibit

c) increase

d) decrease

Answer: b

Explanation: Feedback inhibition acts as a check

point. If the formation of products is too much,

the product itself acts as the inhibitor of the

enzyme thus causing the reaction to stop.

Feedback inhibition loop is found in most of the

cell’s anabolic and catabolic processes.

15. What is the process of synthesis of glucose by

the liver is referred to as?

a) gluconeogenesis

b) neogenesis

c) glycolysis

d) saccharification

Answer: a

Explanation: The anabolic pathway that leads to

the formation of glucose is referred to as

gluconeogenesis. A cell can synthesize glucose at

the same it is utilizing glucose as the source of

chemical energy.

1. Why are enzymes required?

a) Enzymes help to yield more product

b) Enzymes increase the activation energy of the

reaction

c) Enzymes decrease the activation energy of the

reaction

d) Enzymes maintain the equilibrium in the

reaction

Answer: c

Explanation: Chemical reactions need certain

covalent bond breakage within the reactants. For

this, the reactants must contain sufficient kinetic

energy called the activation energy. Enzymes act

as catalysts that speed up the reaction by

lowering the activation energy required for

breaking the covalent bonds.

2. Competitive enzyme inhibitors are ________

a) Reversible inhibitors

b) Irreversible inhibitors

c) Permanent inhibitors

d) None of the mentioned

Answer: a

Explanation: Irreversible inhibitors are those

that bind very tightly to an enzyme, often by

forming a covalent bond to one of its amino acid

residues. Reversible inhibitors bind loosely to an

enzyme and thus are readily displaced.

Competitive inhibitors are reversible inhibitors of

enzyme that compete with a substrate for access

to the active site of the enzyme.

3. Which of the following is a non-competitive

inhibitor against protease produced by HIV?

a) Tipranavir

b) Acetylcholinesterase

c) Ritonavir

d) Phenicols

Answer: a

Explanation: In noncompetitive inhibition, the

substrate and inhibitor do not compete for the

active site of the enzyme and the inhibitor

generally act at other site to bind to the enzyme.

The level of inhibition depends on concentration

of the inhibitor. Tipranavir is non-competitive

inhibitor of the protease produced by HIV when

HIV infects a white blood cell. Ritonavir is a

competitive inhibitor of the protease and

resembles the its peptide substate.

4. Allosteric enzymes are which _______

a) Have single subunit

b) Have multiple subunits

c) Follows Michaelis-Menten kinetics

d) Do not affect the binding affinity

Answer: b

Explanation: Allosteric enzymes are enzymes that

change conformation upon binding of an effector

and affects the binding affinity at a different

binding site. Allosteric enzymes are the exception

to Michaelis-Menten kinetics and usually has

multiple coupled subunits or domains.

5. Feedback inhibition occurs due to _______

a) Excess of the reactants in the reaction

b) Presence of competitive inhibitor

c) Increase in product to a certain level

d) Presence of irreversible inhibitor

Answer: c

Explanation: Feedback inhibition refers to the

inhibition of enzyme activity when a certain end

product is increased beyond a certain level. Due

to accumulation of the product, the enzyme does

form the enzyme-substrate complex in order to

form the product, which is already in excess

6. Enzymes that transfer the phosphate group

from one protein to another is called _____

a) Phosphatase

b) Phosphate transferase

c) Kinase

d) Phosphorylase

Answer: c

Explanation: Kinase is the enzyme that transfers

phosphate group from one protein to another.

Phosphorylase catalyzes addition of phosphate

group from an inorganic phosphate to an

acceptor. Phosphatase enzyme cleaves a

phosphate in presence of water.

7. The enzyme that catalyzes the transfer of a

proton from a reactant to NAD+ is known as ______

a) Hydrolase

b) Proton carrier

c) Dehydrogenase

d) None of the mentioned

Answer: c

Explanation: Dehydrogenase is the enzyme that

catalyzes the removal of a proton tor hydrogen

from a reactant to NAD+. NADH is the reduced

form of NAD+, which is a cofactor in the electron

transport chain.

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8. The functions of ATP are ___________

a) ATP acts as the main source of energy in cells

b) Plays a role in transporting solutes and

proteins across cell membranes

c) Contribute to the building blocks of DNA

d) All of the mentioned

Answer: d

Explanation: Adenosine triphosphate or ATP is

the main source of energy in cells. It releases

energy by breaking into Adenosine diphosphate

(ADP) and inorganic phosphate. It plays a role in

solute transport across cell membranes through

ATPase channels. It is the precursor of Adenine,

which helps in the formation of DNA.

9. In anaerobic respiration, pyruvic acid is

converted to _______

a) Lactate

b) Acetyl CoA

c) PEP

d) Acetate

Answer: a

Explanation: In aerobic respiration, the pyruvate

is converted to two-carbon compound acetyl CoA

which enters the Kreb’s cycle to release carbon

dioxide and energy. In anaerobic respiration, due

to absence of oxygen, the pyruvate is converted to

lactate. In yeast fermentation, pyruvate is

converted to alcohol and carbon dioxide.

10. The cofactor in Haber’s process is __________

a) Molybdenum

b) Iron

c) Copper

d) Magnesium

Answer: a

Explanation: The process of formation of

ammonia from hydrogen and nitrogen is known

as the Haber’s process. The enzyme that catalyzes

the Haber’s reaction needs Molybdenum (Mo) as a

cofactor.

1. Lipids cannot dissolve in _____________

a) organic solvents

b) chloroform

c) benzene

d) water

Answer: d

Explanation: Lipids are vital biomolecules that

have a characteristic property of being able to

dissolve in organic solvents such as benzene and

chloroform and their inability to dissolve in

water.

2. Which types of bonds are found in fats?

a) amide

b) glycosidic

c) ester

d) acidic

Answer: c

Explanation: Fatty acids consist of one glycerol

moiety linked to three fatty acids via ester bonds;

the composite molecule is called triacylglycerol or

neutral fat.

3. How many carboxyl groups are present in fatty

acids?

a) 1

b) 2

c) 3

d) 4

Answer: a

Explanation: Fatty acids are long chain

hydrocarbons containing only one carboxyl group

at the end of the molecule. Three fatty acid chains

link up via ester bonds to a glycerol molecule to

form triacylglycerol. The hydrocarbon chain of

fatty acids is hydrophobic and the carboxyl group

is hydrophilic.

4. Fatty acids that lack double bonds are call

saturated.

a) True

b) False

Answer: a

Explanation: Fatty acids differ from each other by

the length of hydrocarbon chain present and the

nature of bonds between the atoms. Those with

presence of double bonds are called unsaturated

fatty acids and the other group is called saturate

fatty acids.

5. Which type of bonds present in vegetable fats

account for their liquid state?

a) Single bonds

b) Double bonds

c) Amide bonds

d) Glycosidic bonds

Answer: b

Explanation: Double bonds are profusely present

in the vegetable fats which account for their

liquid state at room temperature. Due to this

reason they are also known as polyunsaturated.

Fats that are liquid at room temperature are

called oils

1. In an amino acid, the carboxyl group and

amino group are separated from each other by a

single ____________ atom.

a) nitrogen

b) sulphur

c) hydrogen

d) carbon

Answer: d

Explanation: Proteins are polymers containing

amino acids as monomers. There are twenty

different types of amino acids, with varying

functional groups. Every amino acid has a

carboxyl group and an amino group separated by

a single carbon atom between them.

2. Amino acids used in the synthesis of proteins on

a ribosome are ________________

a) D-amino acids

b) Mutated amino acids

c) L-amino acids

d) Fluorescing amino acids

Answer: c

Explanation: Explanation: In most organisms

including humans, the L amino acid is used to

make up proteins. In some microorganisms D

types are used. The conversion of D to L can take

place in our body using an enzyme call

3. What protein makes up spider silk?

a) Keratin

b) Fibrin

c) Collagen

d) Elastin

Answer: c

Explanation: Spider silk is a collagen molecule

made up of 3 alpha helices wound together in a

triple helix format. It is rich in hydrophobic

residues as well as glycine and proline to

incorporate a flexible nature to it. Collagen is also

found in our bones and tendons.

4. Microorganisms use D-amino acids.

a) True

b) False

Answer: a

Explanation: Unlike animals, microorganism use

D-amino acids in the synthesis of certain small

peptides, including those present in cell walls and

several antibiotics.

5. Which bonds are present in two neighboring

amino acids?

a) Glycosidic bonds

b) Polypeptide bonds

c) Amide bonds

d) Hydrogen bonds

Answer: b

Explanation: Peptide bonds are present between

two consecutive amino acids. Carboxyl group of

one amino acid is bonded to the amino group of

neighboring amino acid, by the elimination of

water.

6. The longest known polypeptide is of the muscle

protein called __________

a) chitin

b) myoglobin

c) titin

d) papain

Answer: c

Explanation: An average polypeptide chain

consists of about 450 amino acids. The longest

known polypeptide chain is found in the muscle

protein called titin, consisting of over 30,000

amino acids.

7. Which of the following amino acids does not

belong to polar charged group?

a) Serine

b) Aspartic acid

c) Lysine

d) Arginine

Answer: a

Explanation: Serine belongs to the category of

polar uncharged amino acids whereas aspartic

acid, lysine, glutamic acid and arginine belong to

polar charged amino acids.

8. Histidine is a polar uncharged amino acid.

a) True

b) False

Answer: b

Explanation: Histidine is considered a polar

charged amino acid although it is not fully

charged at physiological pH. The ability of

Histidine to gain or lose a proton in physiological

pH ranges, it is an important residue in active

sites of many proteins.

1. What is the full form of PPLO?

a) Pleural Parasite Like Organisms

b) Phosphatic Pneumonia Like Organisms

c) Pleuro Parasite Like Organisms

d) Pleuro Pneumonia Like Organisms

Answer: d

Explanation: The full form of PPLO is Pleuro

Pneumonia Like Organisms. They are a type of

prokaryotic organisms, which also include

bacteria, blue – green algae and mycoplasma. The

lack a true nucleus.

2. Which of these is not a basic shape of bacteria?

a) Vibrio

b) Spirillum

c) Triangular

d) Coccus

Answer: c

Explanation: Bacteria have four basic shapes.

These are bacillus or rod – shaped, coccus or

spherical shape, vibrio or comma shaped and

spirillum or spiral shaped. Bacteria are a type of

prokaryotic organisms.

3. Which of these bacteria lack a cell wall?

a) Escherichia

b) Pseudomonas

c) Mycoplasma

d) Mycobacterium

Answer: c

Explanation: All bacteria have a cell wall

covering the cell membrane, except in the genus

mycoplasma. Since all bacteria are prokaryotic

organisms, they do not have a well – defined

nucleus. The genetic material is naked.

4. What is the size of a typical eukaryotic cell?

a) 10 – 20 μm

b) 0.1 – 0.2 μm

c) 100 – 200 μm

d) 1 – 2 μm

Answer: a

Explanation: The size of a typical eukaryotic cell

is 10 – 20 μm. Prokaryotic cells are generally

smaller than eukaryotic cells and also multiply

more rapidly. Bacteria, blue-green algae,

mycoplasma and PPLO (Pleuro Pneumonia Like

Organisms) are the types of prokaryotic cells.

5. What is the shape of a bacterial plasmid?

a) Linear

b) Circular

c) Irregular

d) Bacillus

Answer: b

Explanation: Plasmids are extrachromosomal

small circular DNA that is present in bacterial

cell, apart from the genomic DNA. Plasmid DNA

confers several special features to the cell such as

resistance to certain chemicals.

6. What are plasmid made of?

a) Proteins

b) Polysaccharides

c) Nucleic acids

d) Lipids

Answer: c

Explanation: Plasmids are made of nucleic acids.

They are extrachromosomal small circular DNA

that is present in bacterial cell, apart from the

genomic DNA. Plasmid DNA confers several

special features to the cell.

7. Which of these structures is used in bacterial

transformation?

a) Plasmid

b) Cell membrane

c) Ribosomes

d) Genomic DNA

Answer: a

Explanation: Plasmids are made of nucleic acids.

They are extrachromosomal small circular DNA

that is present in bacterial cell, apart from the

genomic DNA.

8. From which structure is a mesosome derived

from?

a) Plasmid

b) Cell wall

c) Ribosome

d) Cell membrane

Answer: d

Explanation: Mesosome is a characteristic feature

of prokaryotes, which is not present in eukaryotic

cells. It is a differentiated form of cell membrane

derived by the infoldings of the cell membrane in

prokaryotes.

9. How many layers are present in the bacterial

cell envelope?

a) 1

b) 2

c) 3

d) 4

Answer: c

Explanation: Bacterial have a tightly bound three

– layered cell envelope. The uppermost layer is the

glycocalyx, followed by the cell wall in the middle

and the innermost plasma membrane. The cell

envelope provides protection.

10. Gram negative bacteria take up gram strain.

True or false?

a) True

b) False

Answer: b

Explanation: Bacteria are classified into Gram –

positive bacteria and Gram – negative bacteria on

the basis of their response to a staining procedure

known as Gram staining. Gram positive bacteria

take up gram strain.

11. Which of these bacteria have

chromatophores?

a) Escherichia

b) Mycobacteria

c) Mycoplasma

d) Cyanobacteria

Answer: d

Explanation: Chromatophores are pigment

containing membranous extensions in the

cytoplasm of bacteria. Cyanobacteria contain

chromatophores. They are photosynthetic

bacteria that are aquatic in nature.

12. Which of these structures is not a part of the

bacterial flagella?

a) Filament

b) Basal Body

c) Lamina

d) Hook

Answer: c

Explanation: Motile bacteria have a thin

filamentous structure extending from the cell

known as the flagella. Flagella are made of three

parts – the filament which is the longest portion,

the hook and the basal body.

13. Which of these is not a surface structure in

bacteria?

a) Flagella

b) Pili

c) Mesosome

d) Fimbriae

Answer: c

Explanation: Flagella, pili and fimbriae are

structures present on the surface of the bacterial

cell for various purposes such as motility and

attachment. Mesosome is an infolding of cell

membrane, present in the cytoplasm.

14. What are the subunits of prokaryotic

ribosomes?

a) 50S, 30S

b) 60S, 40S

c) 70S, 30S

d) 60S, 30S

Answer: a

Explanation: Prokaryotes have a 70S ribosome

and eukaryotes have an 80S ribosome. The 70S

prokaryotic ribosome contains one large 50S

subunit and one small 30S subunit. It is site of

protein synthesis.

15. Which of these statements is not true

regarding inclusion bodies in prokaryotes?

a) Reserve material is stored in these structures

b) They are bound by a single membrane

c) Gas vacuoles are found in blue-green bacteria

d) They lie free in the cytoplasm

Answer: b

Explanation: Inclusion bodies are not covered by

membranes and lie freely in the cytoplasm. They

store reserve material such as phosphate

granules. blue-green bacteria contain gas

vacuoles which is an inclusion body.

1. Protists survive in ________

a) dry desert

b) aquatic regions

c) dry mountains

d) hot hills

Answer: b

Explanation: Protists survive in aquatic regions.

They can either survive in fresh water lakes, large

oceans, deep seas and marshy areas etc. This is

because their body is adapted to survive in areas

with low oxygen concentration.

2. Which among the following comprises of

animal like protists?

a) Protozoans

b) Chrysophytes

c) Slime molds

d) Dianoflagellates

Answer: a

Explanation: Since, Protozoans are mobile and

can ingest food into their body they resemble

animals. Some of the protozoans follow holozoic

nutrition like that of animals. Therefore,

Protozoans are animal like protists.

3. Diatoms are grouped under _________

a) Chrysophytes

b) Protozoans

c) Dianoflagelletes

d) Euglenoids

Answer: a

Explanation: Diatoms are grouped under

Chrysophytes. Chrysophytes comprise of golden

algae, diatoms and plant like protists etc. It’s

because of the golden-yellow color of the species

they are named as Chrysophytes.

4. Cell wall in diatoms is made of _______

a) Chitin

b) Pectin

c) Silica

d) Cellulose

Answer: c

Explanation: Cell wall in diatoms is made up of

Silica. It’s a double shelled cell wall that fits

exactly into each other like the lid of a box. Cell

wall of diatoms remains in the earth even after

they die and accumulate to form diatomaceous

earth.

5. Diatomaceous earth can be used as a pest

control because _________

a) it is porous

b) it contains silica which is poisonous for pests

when eaten and therefore they die

c) it snatches out lipids from the outermost waxy

layer of pests called cuticle and makes them dry

which results in their death

d) it acts as anesthesia when given in minor

quantities but pests die when large quantities are

in taken

Answer: c

Explanation: Diatomaceous earth is used in pest

control and grain storage. This is because they

are abrasive in nature which snatches out lipids

from the outermost layer of pests called cuticle

and makes them dry which results in their death.

6. Diatoms store food as _______

a) Starch

b) Glucose

c) Oil

d) Fructose

Answer: c

Explanation: Diatoms store food as oil. Plants

store their food as starch. Diatoms are the main

food producing bodies in oceans. They prepare

food by photosynthesis.

7. Chrysophytes contain chlorophyll or carotene

or xanthophyll in them. Their cell wall is rigid and

is made up of chitin.

a) True

b) False

Answer: b

Explanation: Chrysophytes contain chlorophyll or

carotene or xanthophyll in them. Chrysophytes

attain color due to these pigments present in

them. Their cell wall is rigid and is made up of

Cellulose/ Pectin/ Silica.

8. Cell wall in dianoflagelllates contain _______

a) Chitin

b) Cortex

c) Silica

d) Pectin

Answer: b

Explanation: Dianoflagellates have a complex cell

wall made up of cortex. They also possess light

sensitive organelle in their cell. Eye spot is found

in some of them. Erythropsidium is known to have

smallest eye.

9. Dianoflagellates contain ________

a) two flagella with both being transversal

b) two flagella with both being longitudinal

c) two flagella with lone being longitudinal and

other being transversal

d) three flagella with one being along x-axis, other

being along y-axis and the third one being along z-

axis

Answer: c

Explanation: Dianoflagellates contain two

flagella with lone being longitudinal and other

being transversal. These two flagella help them

for their movement and rotation.

10. Dianoflagellates are plant like protists.

a) True

b) False

Answer: b

Explanation: Dianoflagellates are neither plant

nor animal like protists. This is because they

perform both photosynthesis and locomotion.

Therefore, they are neither plants nor animals.

11. What is red tide?

a) Accumulation of cell wall deposits of red algae

is called red tide

b) Accumulation of red blood cells in water

c) Coloration of water due to rapid multiplication

of red dianoflagellates

d) Spread of chrysophytes due to rapid

reproduction

Answer: c

Explanation: Red tide is the coloration of water

due to very rapid multiplication of red

dianoflagellates. Chemicals released due to this

rapid growth are harmful for aquatic life.

12. Which among the following is responsible for

red tide?

a) Gonyaulax

b) Udinium

c) Noctiluca

d) Golden Algae

Answer: a

Explanation: Red tide is the coloration of water

due to very rapid multiplication of red

dianoflagellates like Gonyaulax. Chemicals

released due to this rapid growth are harmful for

aquatic life.

13. Which among the following belong to

plankton?

a) Dianoflagellates

b) Chrysophytes

c) Euglenoids

d) Protozoans

Answer: b

Explanation: Chrysophytes are found in aquatic

habitats. They are present in fresh water as well

as marine. Chrysophytes Are microscopic in

nature and float in water currents like planktons.

14. Protists are unicellular eukaryotes.

a) True

b) False

Answer: b

Explanation: All the unicellular eukaryotes are

placed in Protista. But all protists are not

unicellular. There are few protists that are multi-

cellular. But all the protists are eukaryotic

organisms.

15. Desmids belong to ________

a) Dianoflagellates

b) Chrysophytes

c) Euglenoids

d) Protozoans

Answer: b

Explanation: Chrysophytes comprise of diatoms

and golden algae (desmids). Desmids are

unicellular eukaryotes and can prepare their own

food by photosynthesis. Desmids reproduce both

by sexually and asexually.

1. Which among the following is incorrect about

chordates?

a) They must have notochord at every point of

their life

b) They have a post anal tail

c) They have hollow dorsal nerve cord

d) They have a ventral heart

Answer: a

Explanation: In chordates, notochord at some

point of their life and may vanish after certain

period of time. They have a post anal tail. They

have a dorsal nerve cord. They have a ventral

heart.

2. Which among the following is incorrect about

chordata?

a) They have paired muscles

b) Post anal tail must be present in chordates

c) Their notochord vanishes after certain period

of time

d) Pharyngeal gill slits are present

Answer: b

Explanation: Chordates have paired muscles. Post

anal tail is present at the embryo but might

vanish after certain period of time. Their

notochord also vanishes after certain period of

time. Pharyngeal gill slits are present.

3. Which among the following is odd?

a) Urochordata

b) Cephalochordata

c) Vertebrata

d) Agnatha

Answer: d

Explanation: Urochordata, Cephalochordata and

Vertebrata are sub-phyla of Chordata. These sub-

phyla are classified based on the period of

presence of notochord in Chordates. Whereas

unlike other three options, Agnatha is a super

class in Chordates.

4. Which among the following is not correct about

Urochordata?

a) They are a classification under Protochordates

b) They have post anal tail only till their larval

stage

c) Most of these are marine and almost extinct

d) They don’t contain gill clefts

Answer: d

Explanation: Urochordata is classified under

Protochordates. They have post anal tail only till

their larval stage. Most of these are marine and

almost extinct. They contain pharyngeal gill slits

in the form of gill clefts.

5. Branchiostoma is an example of

Cephalochordata.

a) True

b) False

Answer: a

Explanation: Ascidia, Salpa, Doliolum etc. are

examples of Urochordata. Branchiostoma which

resembles like finless fish is actually an example

of Cephalochordata. The Cephalochordates and

Urochordates are grouped under Protochordates.

6. Which among the following is incorrect about

Vertebrata?

a) All chordates are vertebrates

b) In vertebrates, notochord is replaced by

vertebral column in adults

c) They might not have post-anal tail after a

certain period of time

d) Notochord is present during embryonic period

Answer: a

Explanation: All vertebrates are chordates but

the vice-versa is not true. Notochord is present

during embryonic period. It is replaced by

vertebral column in adults. They might also not

have post-anal tail after a certain period of time.

7. Agnatha is an example of ________

a) Sub-phylum

b) Phylum

c) Super-class

d) Class

Answer: c

Explanation: Super-class is a taxonomic category

that is just above the class and below sub-phylum.

Animal kingdom is divided into 10 phyla and one

among them is Chordates. Chordates are further

classified into two sub-phylum, namely,

protochordates and vertebrata. Vertebrata are

further classified into super classes, namely,

agnatha and gnathostomata.

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8. Which among the following is incorrect about

Agnatha?

a) These are also called as jawless fishes

b) Scales and fins are present

c) They adopt parasitic mode of nutrition

d) They have a circular mouth that acts as sucked

Answer: b

Explanation: Agnatha are also called as jawless

fishes. Scales and fins are absent. They adopt

parasitic mode of nutrition. Their circular mouth

acts as sucker. They are aquatic and most of them

are extinct. The only class that exists in this

super-class is cyclostomata.

9. Which among the following is incorrect about

Cyclostomata?

a) Their vertebral column is made of cartilage

b) Lamprey and hagfish are examples of this class

c) Their digestive system is complete with

stomach, food pipe and intestines

d) Their circulatory system is closed with a 2

chambered heart

Answer: c

Explanation: Vertebral column is made of

cartilage in Cyclostomata. They don’t have a

stomach. Their circulatory system is closed with a

2 chambered heart. Lamprey and hagfish are

examples of this class.

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10. Which among the following is incorrect about

Gnathostomata?

a) These are vertebrates with jaws

b) This super class is classified into Pisces and

tetrapods based on their type of blood

c) Pisces use fins for their movement

d) Tetrapods use limbs for their movement

Answer: b

Explanation: Gnathostomata are vertebrates with

jaws. This super class is classified into psices and

tetrapods based on the organs they use for their

movement. Pisces use fins for their movement.

Tetrapods use limbs for their movement

1. Which among the following is the longest?

a) Stomach

b) Esophagus

c) Small intestine

d) Large intestine

Answer: c

Explanation: Small intestine is the longest part of

the alimentary canal. It is about 20ft or 6metres

long. It is narrow and tubular part occupying the

central and lower parts of abdominal cavity.

2. Small intestine is divided into __________ parts.

a) 1

b) 2

c) 4

d) 3

Answer: d

Explanation: Small intestine is divided into 3

parts. They are duodenum, jejunum and ileum.

3. The opening of Ileum is guarded by ___________

a) Ileo caecal valve

b) Mitral valve

c) Sphincter

d) Villi

Answer: a

Explanation: The opening of Ileum is guarded by

Ileo caecal valve. It prevents regurgitation of food

from caecum. Ileum is highly coiled.

4. Secretin and cholecystokinin are digestive

hormones. These are secreted by __________

a) Esophagus

b) Stomach

c) Ileum

d) Duodenum

Answer: d

Explanation: Duodenum is the widest shortest

and most flexible part of small intestine. It forms

a c shaped curve. It receives bile-pancreatic duct.

5. “Crypts of Lieberkuhn” are found in ___________

a) Gall bladder

b) Intestine

c) Liver

d) Kidney

Answer: b

Explanation: The cells of Crypts of Lieberkuhn

secret intestinal juice as they gradually migrate

along the side of the crypt and the villus.

6. The food that enters the intestine from stomach

is called ___________

a) Chyme

b) Fundus

c) Chyle

d) Bolus

Answer: a

Explanation: Chyme is a semi fluid mass of partly

digested food that is expelled from stomach

through pyloric valve into duodenum.

7. In which of the following putrefying bacteria

are present?

a) Colon

b) Intestine

c) Liver

d) Kidney

Answer: a

Explanation: Colon is found in large intestine. It is

a long sized sacculated structure which is

differentiated into4 regions. They are ascending

colon, transverse colon, descending colon and

sigmoid colon.

8. Which among the following is vestigial in

function?

a) Duodenum

b) Vermiform appendix

c) Peyer’s patch

d) Plicae circulares

Answer: b

Explanation: Vermiform appendix and Caecum

are vestigial function. Since these are not involved

in cellulose digestion.

9. __________ stores the temporary faeces.

a) Colon

b) Caecum

c) Rectum

d) Kidney

Answer: c

Explanation: Rectum is a slightly dilated part and

concerned with the temporary storage of faeces. It

leads into anal canal which opens out by the anus.

10. Large intestine is divided into _________ parts.

a) 3

b) 2

c) 1

d) 4

Answer: a

Explanation: Large intestine is about 5feet long,

shorter but it is wider. It forms an arc around

small intestine. It is formed of 3 parts. They are

caecum, colon and rectum.

1. Identify the valve of the heart.

The cross section of the heart showing bicuspid

valve

a) Pulmonary semilunar valve

b) Aortic semilunar valve

c) Tricuspid valve

d) Bicuspid valve

Answer: d

Explanation: In the given diagram of the cross

section of the heart, the indicated valve is the

bicuspid valve. It is also known as the mitral

valve. The bicuspid valve is the opening between

the left auricle and left ventricle.

2. Identify the blood vessel of the heart.

The blood vessel of the heart superior vena cava

a) Aorta

b) Pulmonary artery

c) Superior vena cava

d) Pulmonary aorta

Answer: c

Explanation: In the given diagram of the cross-

section of the heart, the indicated structure is the

superior vena cava. The superior vena cava

delivers deoxygenated blood from the upper parts

of the body to the heart.

3. In the joint diastole state, which of these events

do not occur?

a) All four chambers are relaxed

b) Both tricuspid and bicuspid valves are open

c) Blood from pulmonary vein flows into the right

atrium

d) Both semilunar valves are closed

Answer: c

Explanation: In the joint diastole state, all four

chambers of the heart are relaxed. The tricuspid

and bicuspid valves are open while the semilunar

valves are closed.

4. Which of these occurs during the atrial systole?

a) Both atria contract simultaneously

b) Action potential is generated by the AVN

initially

c) Tricuspid valve closes

d) The semilunar valves remain open

Answer: a

Explanation: During the atrial systole, both the

atria contract simultaneously while the ventricles

remain relaxed. It occurs due to the action

potential generated by the SAN. The tricuspid and

bicuspid valves open.

5. During atrial systole, blood flow toward the

ventricles increases by what percent?

a) 10%

b) 30%

c) 50%

d) 70%

Answer: b

Explanation: During the atrial systole, both the

atria contract simultaneously while the ventricles

remain relaxed. The increase in pressure in the

atria forces 30% more blood to flow into the

ventricles.

6. Which structure is not responsible for the

transmission of action potential to the ventricles?

a) AV bundle

b) AVN

c) SAN

d) Bundle of His

Answer: c

Explanation: SAN or the sinoatrial node is auto

excitable and is responsible for generating the

action potential. This action potential is

transmitted to the ventricles via the AVN, the AV

bundle and the Bundle of His.

7. Which of these events coincide with ventricular

systole?

a) Atrial diastole

b) Atrial systole

c) Joint diastole

d) Ventricular diastole

Answer: a

Explanation: The relaxation of the atria or the

atrial diastole coincides with the contraction of

the ventricles or the ventricular systole. The right

and left semilunar valves open up due to the

increase in pressure in the ventricles.

8. Which of these events do not occur during

ventricular systole?

a) Closure of tricuspid and bicuspid valves

b) Atrial diastole

c) Opening of the semilunar valves

d) Flow of blood from atria to ventricles

Answer: d

Explanation: During ventricular systole or the

contraction of the ventricles, the tricuspid and

bicuspid valves close and the semilunar valves

open. The atrial diastole occurs at the same time

as the ventricular systole.

9. What happens when the ventricular pressure

decreases?

a) Blood from pulmonary artery flows into

ventricle

b) The semilunar valves remain open

c) The tricuspid and bicuspid valves open

d) Atrial pressure decreases

Answer: c

Explanation: The ventricular pressure decreases

during the ventricular diastole or when the

ventricles relax. The tricuspid and bicuspid valves

open to allow blood to flow from the atria to the

ventricles.

10. The first heart sound occurs due to the closure

of the semilunar valves. True or false?

a) True

b) False

Answer: b

Explanation: Two distinct heart sounds are

audible with the help of the stethoscope. The first

heart sound occurs due to the simultaneous

closure of the bicuspid valve and the tricuspid

valve. It is heard as a ‘lub’.

11. What is the approximate duration of a cardiac

cycle?

a) 0.1 seconds

b) 72 seconds

c) 1 minute

d) 0.8 seconds

Answer: d

Explanation: We know that the heart beats 70-75

times per minute. It beats approximately 72 times

per minute. Hence, 72 cardiac cycles take place in

one minute. Therefore, the duration of one

cardiac cycle is 0.8 seconds.

12. What is the approximate stroke volume?

a) 250 ml

b) 5000 ml

c) 70 ml

d) 500 ml

Answer: c

Explanation: 72 cardiac cycles take place in one

minute. The duration of one cardiac cycle is 0.8

seconds. During each cardiac cycle, each of the

two ventricles pump 70 ml of blood, which is

known as the stroke volume.

13. What is the formula for cardiac output?

a) Stroke volume – heart rate

b) Stroke volume + heart rate

c) Stroke volume × heart rate

d) Stroke volume / heart rate

Answer: c

Explanation: Cardiac output is the product of the

stroke volume and the heart rate. It is the total

amount of blood pumped by each ventricle per

minute. The average cardiac output of a healthy

adult is 5000ml.

14. What is the average cardiac output for a

healthy individual?

a) 5000 ml

b) 70 ml

c) 500 ml

d) 1000 ml

Answer: a

Explanation: The average cardiac output of a

healthy adult is 5000ml or 5 liters. This means

that if the heart rate is 72 beats per minute and

the stroke volume is 70ml, then around 5000ml of

blood is pumped by each ventricle in one minute.

15. Which of these devices is used to hear the

heart sounds?

a) Endoscope

b) Stethoscope

c) Sphygmomanometer

d) Electrocardiograph

Answer: b

Explanation: The heart makes two distinct

sounds, termed ‘lub’ and ‘dub’, which can be

audible to the human ear with the help of an

instrument known as the stethoscope. These

sounds are important for clinical diagnoses

1. IgG is the predominant antibody in the

secretion of respiratory tract.

a) True

b) False

Answer: b

Explanation: There are five types of

immunoglobulins synthesized by the B

lymphocytes. IgA is the predominant antibody

found in the secretions.

2. In all the immunoglobulins, there are _____

type(s) of light chains and ______ type(s) of heavy

chain.

a) 2, 1

b) 2, 2

c) 1, 2

d) 1, 1

Answer: b

Explanation: An antibody or immunoglobulin unit

consists of four protein chains. Two identical

Heavy chains and Light chains joined using a

disulphide bridge.

3. Patients suffering from which of the following

disease contain large quantities of a single type of

antibodies?

a) glioblastoma

b) prostate cancer

c) breast cancer

d) multiple myeloma

Answer: d

Explanation: In multiple myeloma, the plasma

cells go out of control and convert into malignant

cells. The plasma cells make an abnormal

antibody in this disease, the antibodies are known

by several names – monoclonal immunoglobulin,

monoclonal protein etc.

4. Plasma cells are mainly found in the bone

marrow.

a) True

b) False

Answer: a

Explanation: B lymphocytes play vital role in

acquired immunity against diseases and

antigens. Upon contact with an antigen, the B cells

convert to plasma cells, the latter are found

mainly in the bone marrow which is the soft

tissue inside the bones.

5. The antigenic determinant is called

_________________

a) epitope

b) epitome

c) microbiome

d) metagenome

Answer: a

Explanation: The antigenic determinant – epitome

is the combining site of an antibody that has a

complementary stereochemical structure to a

particular portion of the antigen. Different

antibodies contain variable epitopes.

6. Binding of which of the following antibody’s

heavy chain initiates the lysis of bound bacterial

cells?

a) IgM

b) IgD

c) IgA

d) IgE

Answer: a

Explanation: Binding of heavy chain of IgM leads

to the activation of complement system that

initiates the lysis of bacterial cells to which the

antibody is bound. Similarly, binding of heavy

chain of IgE initiates the allergic responses.

7. In which year was the two “gene – one

polypeptide” hypothesis put forward?

a) 1945

b) 1955

c) 1965

d) 1975

Answer: c

Explanation: The “two gene – one polypeptide”

hypothesis was put forward in the year 1965 by

William Dreyer of the California Institute of

Technology and J. Claude Bennett of the University

of Alabama.

8. Which segment of chromosome 2 encodes for

the V region of antibody?

a) A segment

b) C segment

c) V-segment

d) J-segment

Answer: d

Explanation: The small portion of the

chromosome 2 that encodes for V region (variable

region of the immunoglobulin) is called the J

segment. On the chromosomes, the genes encoding

for variable and constant regions of the

chromosomes are segregated.

9. Class-switching of antibodies can occur by

changing the ___________________

a) heavy chain

b) light chain

c) pH

d) temperature

Answer: a

Explanation: The class-switching of antibodies

can take place by changing the heavy chains of

immunoglobulins without make any change to the

antigen binding region. B cells can change the

antibodies they make even after producing them.

10. Cyclosporin A is a drug that __________________

a) suppresses the immune system

b) increases body temperature

c) increases the production of antibodies

d) decreases body temperature

Answer: a

Explanation: Cyclosporin A is a drug that

suppresses immune system following transplant

surgery. It is a cyclic peptide produced by a soil

fungus that inhibits the phosphatasein the

signaling pathway that leads to the production of

cytokines.

11. Fragments of antigens are held at the surface

of antigen presenting cells by _________________

a) histones

b) antibodies

c) major histocompatibility complex

d) epitope

Answer: c

Explanation: Fragments of antigens are held at

the surfaces of antigen presenting cells (APCs)

with the help of MHC (major histocompatibility

complex) molecules. The T lymphocytes are

activated with the help of antigen presenting cells