Q.1 What type of stem cell can develop into any cell type in the body?
Adult stem cell
Pluripotent stem cell
Totipotent stem cell
Committed stem cell
Explanation - Totipotent stem cells can give rise to all cell types including extraembryonic tissues, while pluripotent cells generate only embryonic cells.
Correct answer is: Totipotent stem cell
Q.2 Which of the following is NOT a characteristic of adult stem cells?
Limited differentiation potential
Found in specific tissues
Can divide indefinitely
Do not need to be isolated in culture
Explanation - Adult stem cells are usually isolated and expanded in culture before use; they cannot divide indefinitely without manipulation.
Correct answer is: Do not need to be isolated in culture
Q.3 Which of these is a commonly used scaffold material in tissue engineering?
Gold nanoparticles
Hydroxyapatite
Silicon dioxide
Polyethylene glycol
Explanation - Hydroxyapatite mimics bone mineral and is widely used as a scaffold for bone tissue engineering.
Correct answer is: Hydroxyapatite
Q.4 Stem cells that are derived from a patient's own cells and reprogrammed to a pluripotent state are called?
Embryonic stem cells
Induced pluripotent stem cells
Mesenchymal stem cells
Hematopoietic stem cells
Explanation - Induced pluripotent stem cells (iPSCs) are generated by reprogramming adult cells back to a pluripotent state.
Correct answer is: Induced pluripotent stem cells
Q.5 Which of the following best describes the role of growth factors in tissue engineering?
They provide structural support to cells
They act as antibiotics
They guide cell differentiation and proliferation
They form the scaffold's backbone
Explanation - Growth factors are signaling molecules that stimulate cells to grow, differentiate, and form tissues.
Correct answer is: They guide cell differentiation and proliferation
Q.6 Which type of stem cell is commonly used for bone marrow transplants?
Neural stem cells
Mesenchymal stem cells
Hematopoietic stem cells
Cardiac stem cells
Explanation - Hematopoietic stem cells (HSCs) give rise to all blood cells and are the basis of bone marrow transplants.
Correct answer is: Hematopoietic stem cells
Q.7 Which ethical concern is associated with embryonic stem cell research?
Use of animal subjects
Destruction of human embryos
High cost of research
Lack of regulatory approval
Explanation - Embryonic stem cell derivation requires the destruction of embryos, raising ethical objections.
Correct answer is: Destruction of human embryos
Q.8 What is the primary difference between totipotent and pluripotent stem cells?
Totipotent cells can become any cell type; pluripotent cannot
Totipotent cells are found in adults; pluripotent in embryos
Totipotent cells can form all tissues including placenta; pluripotent cannot
Totipotent cells are derived from reprogramming; pluripotent are naturally occurring
Explanation - Totipotent cells can generate both embryonic and extraembryonic tissues, whereas pluripotent cells generate only embryonic lineages.
Correct answer is: Totipotent cells can form all tissues including placenta; pluripotent cannot
Q.9 Which of these is a common method to differentiate iPSCs into cardiomyocytes?
Mechanical stretching
Chemical inhibition of GSK3
Heat shock
Radiation exposure
Explanation - Inhibiting GSK3 with small molecules activates Wnt signaling pathways that promote cardiac differentiation.
Correct answer is: Chemical inhibition of GSK3
Q.10 What is a major risk associated with the use of pluripotent stem cells in therapy?
Rapid differentiation
High cost
Tumorigenesis
Low proliferation rate
Explanation - Pluripotent cells can form teratomas if not fully differentiated before implantation.
Correct answer is: Tumorigenesis
Q.11 Which scaffold fabrication technique allows precise control over pore size?
Freeze-drying
3D bioprinting
Solvent casting
Electrospinning
Explanation - 3D bioprinting builds scaffolds layer-by-layer, enabling accurate pore size and geometry control.
Correct answer is: 3D bioprinting
Q.12 What does the term 'xenoantigen' refer to in the context of regenerative medicine?
Human immune cells attacking foreign tissues
Antigens from the same species
Antigens from a different species
Antigens that induce tolerance
Explanation - Xenoantigens are non-self antigens originating from another species that can trigger immune rejection.
Correct answer is: Antigens from a different species
Q.13 Which growth factor is essential for neural stem cell maintenance?
FGF-2
VEGF
EGF
PDGF
Explanation - Fibroblast growth factor 2 (FGF-2) supports proliferation and undifferentiated state of neural stem cells.
Correct answer is: FGF-2
Q.14 Which of the following is NOT typically used as a biomaterial in tissue engineering?
Alginate
Collagen
Chitin
Teflon
Explanation - Teflon is chemically inert and not biocompatible for tissue engineering applications.
Correct answer is: Teflon
Q.15 What is the primary function of a bioreactor in regenerative medicine?
Store stem cells for long periods
Maintain cells in a controlled environment to scale up production
Deliver drugs to patients
Monitor patient vitals
Explanation - Bioreactors provide a scalable, controlled setting for expanding cells under optimal conditions.
Correct answer is: Maintain cells in a controlled environment to scale up production
Q.16 Which of these diseases has been successfully treated using stem cell therapy?
Sickle cell anemia
Alzheimer’s disease
Type 1 diabetes
All of the above
Explanation - Stem cell transplantation has shown promise in treating sickle cell anemia by restoring healthy blood cells.
Correct answer is: Sickle cell anemia
Q.17 What is the main advantage of using induced pluripotent stem cells over embryonic stem cells?
They are cheaper to produce
They eliminate ethical concerns
They differentiate faster
They form tumors less frequently
Explanation - iPSCs are derived from adult cells, avoiding the destruction of embryos and related ethical issues.
Correct answer is: They eliminate ethical concerns
Q.18 In regenerative medicine, the term 'tissue niche' refers to:
The entire organ where cells reside
The microenvironment that maintains stem cell properties
The scaffold used in tissue engineering
The area of inflammation after injury
Explanation - The niche provides signals that regulate stem cell self-renewal and differentiation.
Correct answer is: The microenvironment that maintains stem cell properties
Q.19 What type of stem cell is most commonly used in cartilage repair?
Neural stem cells
Mesenchymal stem cells
Hematopoietic stem cells
Induced pluripotent stem cells
Explanation - MSCs can differentiate into chondrocytes and are widely applied in cartilage regeneration.
Correct answer is: Mesenchymal stem cells
Q.20 Which of the following best describes 'bioprinting'?
Printing tissue onto a 2D surface
Printing layers of bioink to create 3D structures
Printing cells on paper
Printing DNA sequences
Explanation - Bioprinting constructs 3D tissue architectures by depositing bioink layer by layer.
Correct answer is: Printing layers of bioink to create 3D structures
Q.21 Which enzyme is commonly used to isolate mesenchymal stem cells from bone marrow?
Trypsin
Collagenase
Lipase
Protease K
Explanation - Collagenase digests collagen in bone marrow, freeing MSCs for collection.
Correct answer is: Collagenase
Q.22 What is the term for the process where stem cells develop into a specific cell type?
Reprogramming
Differentiation
Proliferation
Apoptosis
Explanation - Differentiation is the specialization of stem cells into distinct lineages.
Correct answer is: Differentiation
Q.23 Which of these is a common marker used to identify neural stem cells?
CD34
Nestin
Oct4
Sox2
Explanation - Nestin is an intermediate filament protein expressed in neural progenitor cells.
Correct answer is: Nestin
Q.24 Which scaffold material is derived from a natural polymer and is often used in skin tissue engineering?
Polyethylene glycol
Silk fibroin
Polylactic acid
Polyurethane
Explanation - Silk fibroin is a natural protein used as a biocompatible scaffold for skin regeneration.
Correct answer is: Silk fibroin
Q.25 Which of the following is NOT a source of mesenchymal stem cells?
Adipose tissue
Bone marrow
Umbilical cord blood
Dental pulp
Explanation - While cord blood contains HSCs, MSCs are predominantly found in bone marrow, adipose, and dental pulp.
Correct answer is: Umbilical cord blood
Q.26 Which signaling pathway is crucial for maintaining stem cell pluripotency?
Wnt/β-catenin
Notch
TGF-β
All of the above
Explanation - Wnt, Notch, and TGF-β pathways all contribute to the regulation of pluripotency in stem cells.
Correct answer is: All of the above
Q.27 In tissue engineering, what role does a 'bioreactor' play?
It provides mechanical support to scaffolds
It delivers nutrients and removes waste to support cell growth
It sterilizes the scaffold before implantation
It shapes the scaffold into complex geometries
Explanation - A bioreactor creates a controlled environment for cell culture, optimizing growth conditions.
Correct answer is: It delivers nutrients and removes waste to support cell growth
Q.28 Which of the following diseases is a target for stem cell-based therapy?
Parkinson’s disease
Celiac disease
Cholera
Tetanus
Explanation - Stem cell therapy aims to replace lost dopaminergic neurons in Parkinson's disease.
Correct answer is: Parkinson’s disease
Q.29 What is the main advantage of using hydrogel scaffolds in regenerative medicine?
They provide rigid support
They can encapsulate cells and deliver growth factors
They are inexpensive
They are non-biodegradable
Explanation - Hydrogels are highly porous and can mimic the extracellular matrix for cell encapsulation.
Correct answer is: They can encapsulate cells and deliver growth factors
Q.30 Which of the following is a common source of induced pluripotent stem cells (iPSCs)?
Skin fibroblasts
Blood cells
Brain tissue
All of the above
Explanation - iPSCs can be generated from various adult cell types, including fibroblasts and blood cells.
Correct answer is: All of the above
Q.31 Which factor is essential for maintaining the stemness of hematopoietic stem cells?
Stem cell factor (SCF)
Fibroblast growth factor (FGF)
Vascular endothelial growth factor (VEGF)
Bone morphogenetic protein (BMP)
Explanation - SCF binds to its receptor c-Kit and promotes self-renewal of HSCs.
Correct answer is: Stem cell factor (SCF)
Q.32 Which of these is a major challenge in translating stem cell therapies to the clinic?
High differentiation rates
Limited scalability
Risk of immune rejection
All of the above
Explanation - Challenges include low efficiency, scale-up limitations, and potential immune responses.
Correct answer is: All of the above
Q.33 What is the main function of the extracellular matrix (ECM) in tissue engineering?
Providing structural support and biochemical cues
Storing energy reserves
Regulating body temperature
Acting as a barrier to infection
Explanation - ECM components like collagen give mechanical strength and signal cells to differentiate.
Correct answer is: Providing structural support and biochemical cues
Q.34 Which of these materials is considered a synthetic polymer used for creating biodegradable scaffolds?
Polylactic acid (PLA)
Gelatin
Chitosan
Collagen
Explanation - PLA is a biodegradable synthetic polymer commonly used in scaffold fabrication.
Correct answer is: Polylactic acid (PLA)
Q.35 Which of the following statements about autologous stem cell transplants is true?
They use donor-derived cells
They eliminate the risk of graft-versus-host disease
They are illegal in many countries
They require immunosuppression
Explanation - Using a patient’s own cells avoids immune rejection and GVHD.
Correct answer is: They eliminate the risk of graft-versus-host disease
Q.36 Which growth factor is known to promote angiogenesis in tissue engineering?
Insulin-like growth factor 1 (IGF-1)
Vascular endothelial growth factor (VEGF)
Fibroblast growth factor 2 (FGF-2)
Transforming growth factor beta (TGF-β)
Explanation - VEGF stimulates the growth of new blood vessels essential for tissue survival.
Correct answer is: Vascular endothelial growth factor (VEGF)
Q.37 Which of the following is a key factor in preventing stem cell senescence during culture?
Low oxygen concentration
High serum concentration
Rapid passaging
Cold storage
Explanation - Hypoxic conditions better mimic the stem cell niche and reduce senescence.
Correct answer is: Low oxygen concentration
Q.38 What is the role of chondrogenic differentiation in cartilage tissue engineering?
To produce bone cells
To create cartilage-specific extracellular matrix
To generate neural tissue
To produce blood vessels
Explanation - Chondrogenic differentiation directs stem cells to produce cartilage components like collagen II.
Correct answer is: To create cartilage-specific extracellular matrix
Q.39 Which of these is an advantage of using mesenchymal stem cells over embryonic stem cells?
Higher tumorigenic potential
No ethical concerns
Unlimited differentiation ability
Fast growth rates
Explanation - MSCs can be harvested from adult tissues, avoiding the ethical issues of ESCs.
Correct answer is: No ethical concerns
Q.40 Which of the following best describes the 'Yamanaka factors'?
Growth factors used in scaffolds
Transcription factors used to reprogram cells into iPSCs
Enzymes that digest extracellular matrix
Markers for mesenchymal stem cells
Explanation - The Yamanaka factors (Oct4, Sox2, Klf4, c-Myc) reprogram adult cells to a pluripotent state.
Correct answer is: Transcription factors used to reprogram cells into iPSCs
Q.41 What is a common method for delivering stem cells to a target tissue?
Intravenous injection
Topical application
Intraperitoneal injection
All of the above
Explanation - IV injection is often used for systemic delivery of stem cells to target organs.
Correct answer is: Intravenous injection
Q.42 Which of the following is NOT a typical feature of stem cells?
Unlimited self-renewal
Differentiation into specific cell types
High metabolic activity
Low proliferation potential
Explanation - Stem cells generally have a high proliferation potential to replenish tissues.
Correct answer is: Low proliferation potential
Q.43 What is the significance of the 'stem cell niche' in vivo?
It stores stem cells for future use
It provides signals that regulate stem cell fate
It acts as a storage battery
It is irrelevant to stem cell biology
Explanation - The niche microenvironment controls stem cell self-renewal and differentiation.
Correct answer is: It provides signals that regulate stem cell fate
Q.44 Which of these is a characteristic of a good scaffold material?
Non-biodegradability
Immunogenicity
Biocompatibility
High cost
Explanation - Scaffolds must be compatible with host tissue and not provoke an immune response.
Correct answer is: Biocompatibility
Q.45 Which type of stem cell can be found in the bone marrow?
Neural stem cell
Hematopoietic stem cell
Cardiac stem cell
All of the above
Explanation - HSCs reside in the bone marrow and generate blood lineages.
Correct answer is: Hematopoietic stem cell
Q.46 What is a major concern with using xenografts in regenerative medicine?
High cost of production
Risk of transmitting diseases
Limited availability
All of the above
Explanation - Xenografts can carry zoonotic pathogens that may infect human recipients.
Correct answer is: Risk of transmitting diseases
Q.47 Which cell surface marker is commonly used to isolate mesenchymal stem cells?
CD34
CD45
CD73
CD14
Explanation - CD73 is one of the positive markers expressed on MSCs used for selection.
Correct answer is: CD73
Q.48 Which of the following is a benefit of using 3D printing in tissue engineering?
It allows for uniform cell distribution
It eliminates the need for scaffolds
It ensures immediate implantation without culture
All of the above
Explanation - 3D printing can place cells precisely within a scaffold structure for better tissue formation.
Correct answer is: It allows for uniform cell distribution
Q.49 Which of these is an ethical consideration when working with embryonic stem cells?
Potential for genetic manipulation
Destruction of embryos
High cost of maintenance
All of the above
Explanation - Deriving ESCs involves destroying human embryos, raising ethical concerns.
Correct answer is: Destruction of embryos
Q.50 What is the purpose of using 'bioreactors' during stem cell expansion?
To maintain a static environment
To provide dynamic culture conditions and scalability
To sterilize the cells
To deliver drugs to the cells
Explanation - Bioreactors support large-scale expansion and control of cell culture parameters.
Correct answer is: To provide dynamic culture conditions and scalability
Q.51 Which of the following is a key advantage of using iPSCs?
Unlimited proliferation without genetic manipulation
No risk of tumor formation
They bypass ethical issues related to embryos
They are naturally found in the body
Explanation - iPSCs are derived from adult cells, avoiding the destruction of embryos.
Correct answer is: They bypass ethical issues related to embryos
Q.52 Which factor is necessary for maintaining pluripotency in stem cells?
BMP-4
Noggin
TGF-β1
All of the above
Explanation - BMP inhibitors like Noggin and TGF-β signaling help preserve pluripotency.
Correct answer is: All of the above
Q.53 What is the primary use of mesenchymal stem cells in regenerative medicine?
To treat blood disorders
To regenerate bone and cartilage
To replace neurons
To treat infections
Explanation - MSCs are extensively used for bone and cartilage repair due to their differentiation potential.
Correct answer is: To regenerate bone and cartilage
Q.54 Which of these materials is commonly used as a hydrogel in tissue engineering?
Polyvinyl alcohol
Silicon nitride
Polystyrene
Glass
Explanation - PVA hydrogels are biocompatible and widely used for cell encapsulation.
Correct answer is: Polyvinyl alcohol
Q.55 What is the main challenge when using stem cells for heart regeneration?
Immune rejection
Poor electrical coupling
High differentiation efficiency
Low cell survival rates
Explanation - Many transplanted cells die in the hostile environment of the damaged heart.
Correct answer is: Low cell survival rates
Q.56 Which of the following is a characteristic of a scaffold that mimics the natural extracellular matrix?
High stiffness
Large pores
Biodegradability
All of the above
Explanation - A natural ECM-like scaffold should degrade over time, allowing new tissue to form.
Correct answer is: Biodegradability
Q.57 Which of the following best describes the difference between autologous and allogeneic stem cell therapies?
Autologous uses donor cells; allogeneic uses the patient's cells
Autologous uses the patient's cells; allogeneic uses donor cells
Both use the patient's cells
Both use donor cells
Explanation - Autologous therapies avoid immune rejection; allogeneic therapies rely on donor tissues.
Correct answer is: Autologous uses the patient's cells; allogeneic uses donor cells
Q.58 Which of these is a potential risk when using stem cells for therapeutic applications?
Infection transmission
Tumor formation
Immune rejection
All of the above
Explanation - All listed risks are concerns in clinical stem cell therapy.
Correct answer is: All of the above
Q.59 Which growth factor is commonly used to promote neural stem cell differentiation into neurons?
Neuregulin-1
Transforming growth factor beta (TGF-β)
Bone morphogenetic protein 4 (BMP-4)
Platelet-derived growth factor (PDGF)
Explanation - Neuregulin-1 drives neuronal differentiation of neural progenitor cells.
Correct answer is: Neuregulin-1
Q.60 Which type of stem cell has been used in clinical trials for treating spinal cord injury?
Hematopoietic stem cells
Mesenchymal stem cells
Neural stem cells
Embryonic stem cells
Explanation - MSCs have immunomodulatory properties beneficial for spinal cord repair.
Correct answer is: Mesenchymal stem cells
Q.61 Which of the following is a primary advantage of using 3D bioprinting in tissue engineering?
Reduced cost of materials
Precise control over architecture
No need for cell culture
Immediate tissue function
Explanation - 3D bioprinting allows exact placement of cells and scaffold material, improving tissue design.
Correct answer is: Precise control over architecture
Q.62 Which of these markers is commonly expressed on hematopoietic stem cells?
CD34
CD45
CD73
CD90
Explanation - CD34 is a transmembrane protein used as a marker for HSCs.
Correct answer is: CD34
Q.63 What is the role of oxygen concentration in stem cell culture?
Higher oxygen promotes faster growth
Lower oxygen mimics stem cell niche and reduces differentiation
It has no effect
It only affects cell death
Explanation - Hypoxia helps maintain stemness by mimicking the natural low-oxygen niche.
Correct answer is: Lower oxygen mimics stem cell niche and reduces differentiation
Q.64 Which of the following is a potential application of stem cell therapy?
Treating diabetes
Repairing cartilage
Generating artificial organs
All of the above
Explanation - Stem cell therapy is being explored for a variety of diseases and tissue repair.
Correct answer is: All of the above
Q.65 Which scaffold fabrication method involves freezing a polymer solution followed by sublimation of ice crystals?
Electrospinning
Freeze-drying
Solvent casting
Compression molding
Explanation - Freeze-drying creates porous scaffolds by sublimating ice crystals formed during freezing.
Correct answer is: Freeze-drying
Q.66 Which of these is an example of a regenerative therapy using stem cells?
Bone marrow transplant
Heart bypass surgery
Surgical removal of a tumor
All of the above
Explanation - Bone marrow transplants involve transplanting stem cells to restore blood formation.
Correct answer is: Bone marrow transplant
Q.67 Which type of stem cell is known for its ability to differentiate into both ectodermal and mesodermal lineages?
Totipotent stem cells
Multipotent stem cells
Pluripotent stem cells
Unipotent stem cells
Explanation - Pluripotent stem cells can generate all embryonic lineages except extraembryonic tissues.
Correct answer is: Pluripotent stem cells
Q.68 Which of the following is a key advantage of using synthetic polymers as scaffold materials?
They degrade into toxic byproducts
They have predictable mechanical properties
They are naturally derived
They are always non-biodegradable
Explanation - Synthetic polymers can be engineered for specific stiffness and degradation rates.
Correct answer is: They have predictable mechanical properties
Q.69 Which of these is a main challenge in scaling up stem cell production for clinical use?
Maintaining cell quality
Ensuring sterility
Controlling cost
All of the above
Explanation - Scale-up requires quality control, sterility, and cost-effective processes.
Correct answer is: All of the above
Q.70 Which of the following is a characteristic of embryonic stem cells?
They are found in adult tissues
They can form teratomas
They are immunogenic
They have limited self-renewal
Explanation - ESCs can differentiate into all cell types, including teratoma formation in vivo if undifferentiated.
Correct answer is: They can form teratomas
Q.71 Which of the following is a common scaffold material used for bone tissue engineering?
Hydroxyapatite
Silk
Chitosan
Polyethylene glycol
Explanation - HA closely mimics natural bone mineral, promoting osteogenesis.
Correct answer is: Hydroxyapatite
Q.72 Which of the following best describes the 'stem cell niche'?
A region where stem cells die
The microenvironment that regulates stem cell fate
The storage location for stem cells in the laboratory
The name of a new technology
Explanation - The niche provides signals that influence self-renewal and differentiation.
Correct answer is: The microenvironment that regulates stem cell fate
Q.73 Which of the following is a method to induce differentiation of stem cells into neurons?
Adding retinoic acid
Increasing oxygen levels
Using high glucose media
None of the above
Explanation - Retinoic acid promotes neuronal differentiation of stem cells in vitro.
Correct answer is: Adding retinoic acid
Q.74 Which of the following is a common source of mesenchymal stem cells?
Blood
Adipose tissue
Skin
All of the above
Explanation - MSCs can be isolated from multiple adult tissues, including adipose and skin.
Correct answer is: All of the above
Q.75 Which of the following is an ethical concern related to stem cell research?
Use of animals in experiments
Potential for genetic manipulation
Destruction of human embryos
All of the above
Explanation - The derivation of ESCs involves destroying embryos, raising ethical questions.
Correct answer is: Destruction of human embryos
Q.76 Which of the following is a major advantage of using induced pluripotent stem cells?
They can be derived from adult cells without using embryos
They do not risk forming tumors
They proliferate faster than embryonic stem cells
They require no reprogramming
Explanation - iPSCs avoid ethical issues associated with ESCs by reprogramming adult cells.
Correct answer is: They can be derived from adult cells without using embryos
Q.77 Which of the following is a common method for delivering stem cells to a target tissue?
Intravenous injection
Direct injection
Topical application
All of the above
Explanation - Stem cells can be delivered via multiple routes depending on the disease context.
Correct answer is: All of the above
Q.78 Which of the following is a potential complication of stem cell transplantation?
Tumor formation
Immune rejection
Infection
All of the above
Explanation - Complications can include tumorigenesis, rejection, and infection.
Correct answer is: All of the above
Q.79 Which of the following is a characteristic of a scaffold used for tissue engineering?
Biodegradable
Highly porous
Provides mechanical support
All of the above
Explanation - Effective scaffolds degrade over time and support cell growth while being porous.
Correct answer is: All of the above
Q.80 Which of the following is a common marker for mesenchymal stem cells?
CD34
CD45
CD73
CD133
Explanation - CD73 is commonly expressed on MSCs and used for their identification.
Correct answer is: CD73
Q.81 Which of the following is an advantage of using 3D bioprinting for tissue engineering?
Precise control over cell placement
Eliminates the need for scaffolds
Reduces the cost of materials
All of the above
Explanation - 3D bioprinting allows accurate spatial arrangement of cells and materials.
Correct answer is: Precise control over cell placement
Q.82 Which of the following is a common application of stem cells in regenerative medicine?
Treating cardiovascular diseases
Repairing damaged cartilage
All of the above
None of the above
Explanation - Stem cell therapies are explored for various diseases including heart and cartilage repair.
Correct answer is: All of the above
Q.83 Which type of stem cell is found in the bone marrow and can give rise to blood cells?
Mesenchymal stem cell
Hematopoietic stem cell
Neural stem cell
Cardiac stem cell
Explanation - HSCs reside in bone marrow and produce all blood lineages.
Correct answer is: Hematopoietic stem cell
Q.84 Which of the following is a benefit of using synthetic polymers as scaffold materials?
They are always biocompatible
They allow precise control over mechanical properties
They degrade into natural metabolites
They are derived from natural sources
Explanation - Synthetic polymers can be engineered for desired stiffness and degradation.
Correct answer is: They allow precise control over mechanical properties
Q.85 Which of the following is NOT a source of stem cells commonly used in research?
Embryonic tissue
Adult tissue
Synthetic cells
Blood
Explanation - Stem cells are biological; synthetic cells are not a source in this context.
Correct answer is: Synthetic cells
Q.86 What is the main advantage of using mesenchymal stem cells for tissue repair?
They can differentiate into many cell types
They have low immunogenicity
They can be harvested from many tissues
All of the above
Explanation - MSCs are multipotent, low immunogenic, and can be isolated from various tissues.
Correct answer is: All of the above
Q.87 Which of these is a key factor that influences stem cell differentiation?
Mechanical cues
Chemical signals
Temperature
All of the above
Explanation - Physical, chemical, and thermal cues all affect stem cell fate decisions.
Correct answer is: All of the above
Q.88 Which of the following is a common scaffold fabrication technique?
Freeze-drying
Compression molding
Solvent casting
All of the above
Explanation - All listed methods are used to create scaffolds for tissue engineering.
Correct answer is: All of the above
Q.89 Which type of stem cell can become any type of cell in the body?
Totipotent stem cell
Pluripotent stem cell
Multipotent stem cell
Unipotent stem cell
Explanation - Totipotent cells can generate all cell types, including extraembryonic tissues.
Correct answer is: Totipotent stem cell
Q.90 Which of these is an example of a growth factor used in tissue engineering?
Insulin
VEGF
Chondroitin sulfate
Collagen
Explanation - VEGF stimulates the growth of new blood vessels within engineered tissues.
Correct answer is: VEGF
Q.91 What is a major concern when using stem cells for clinical applications?
Risk of infection
Risk of tumor formation
Risk of immune rejection
All of the above
Explanation - Clinical stem cell therapy must consider infection, tumorigenesis, and immune responses.
Correct answer is: All of the above
Q.92 Which of the following is a typical cell type derived from stem cells for cartilage repair?
Fibroblasts
Chondrocytes
Osteoclasts
Adipocytes
Explanation - Chondrocytes are the cartilage-specific cells produced by differentiated stem cells.
Correct answer is: Chondrocytes
Q.93 Which of the following is a method used to produce induced pluripotent stem cells?
Transfection with reprogramming factors
Isolation from umbilical cord
Differentiation from adult stem cells
All of the above
Explanation - iPSCs are generated by introducing transcription factors like Oct4, Sox2, Klf4, and c-Myc.
Correct answer is: Transfection with reprogramming factors
Q.94 Which scaffold material is known for its biodegradability and use in bone tissue engineering?
Polyethylene glycol
Polylactic acid
Silicon nitride
Glass
Explanation - PLA is biodegradable and often used for bone scaffold fabrication.
Correct answer is: Polylactic acid
Q.95 Which of the following is NOT a characteristic of mesenchymal stem cells?
They can differentiate into bone cells
They have low immunogenicity
They are found in bone marrow and adipose tissue
They can become any cell type in the body
Explanation - MSCs are multipotent, not pluripotent; they cannot become all cell types.
Correct answer is: They can become any cell type in the body
Q.96 Which of the following is a commonly used scaffold material for skin regeneration?
Silk fibroin
Hydroxyapatite
Collagen
All of the above
Explanation - All listed materials can serve as scaffolds for skin tissue engineering.
Correct answer is: All of the above
Q.97 What is the main reason for using a bioreactor in stem cell culture?
To maintain a static environment
To control oxygen levels and provide mechanical stimuli
To sterilize the cells
To reduce cost
Explanation - Bioreactors allow dynamic culture conditions that support cell growth and differentiation.
Correct answer is: To control oxygen levels and provide mechanical stimuli
Q.98 Which of the following is an advantage of using induced pluripotent stem cells?
They bypass ethical concerns of embryonic stem cells
They cannot differentiate into all cell types
They are not tumorigenic
They do not require reprogramming
Explanation - iPSCs are derived from adult cells, avoiding the destruction of embryos.
Correct answer is: They bypass ethical concerns of embryonic stem cells
Q.99 Which of the following is a risk factor for tumorigenesis in stem cell therapies?
Use of undifferentiated pluripotent cells
Low oxygen culture
High cell density
All of the above
Explanation - Undifferentiated pluripotent cells can form teratomas if not fully committed.
Correct answer is: Use of undifferentiated pluripotent cells
Q.100 Which of the following is a key component of the extracellular matrix that supports stem cell attachment?
Collagen
Chondroitin sulfate
Hydroxyapatite
Gelatin
Explanation - Collagen provides a structural framework for cell attachment and growth.
Correct answer is: Collagen
Q.101 What is the role of the scaffold in tissue engineering?
Providing mechanical support
Guiding cell growth and differentiation
Both A and B
None of the above
Explanation - Scaffolds serve as a 3D framework for cell attachment and direct tissue formation.
Correct answer is: Both A and B
Q.102 Which of the following best describes 'stem cell niche'?
A physical location where stem cells reside and receive signals
A laboratory technique for isolating stem cells
A type of scaffold material
A disease caused by stem cells
Explanation - The niche is the microenvironment that regulates stem cell behavior.
Correct answer is: A physical location where stem cells reside and receive signals
Q.103 Which of the following is a type of stem cell commonly used in regenerative medicine for bone repair?
Hematopoietic stem cell
Mesenchymal stem cell
Neural stem cell
Cardiac stem cell
Explanation - MSCs can differentiate into osteoblasts and are frequently used for bone regeneration.
Correct answer is: Mesenchymal stem cell
Q.104 Which of the following is a common method for delivering growth factors in tissue engineering?
Incorporation into scaffolds
Direct injection
All of the above
None of the above
Explanation - Growth factors can be embedded in scaffolds or injected directly to influence cell behavior.
Correct answer is: All of the above
Q.105 Which of the following is NOT a characteristic of a scaffold material for regenerative medicine?
Biodegradability
Porosity
Immunogenicity
Mechanical strength
Explanation - A good scaffold should be non-immunogenic to avoid rejection.
Correct answer is: Immunogenicity
Q.106 Which of the following is a major challenge in using stem cells for heart repair?
Low cell survival after transplantation
Poor electrical coupling with host tissue
Difficulty in obtaining cells
All of the above
Explanation - Cardiac stem cell therapy faces cell survival, integration, and sourcing challenges.
Correct answer is: All of the above
Q.107 Which of the following is a common source of adult stem cells?
Bone marrow
Skin
Adipose tissue
All of the above
Explanation - Adult stem cells can be isolated from multiple tissues such as bone marrow, skin, and fat.
Correct answer is: All of the above
Q.108 Which of the following is a factor that influences stem cell differentiation?
Mechanical forces
Chemical signals
Temperature
All of the above
Explanation - Stem cell fate is regulated by a combination of mechanical, chemical, and thermal cues.
Correct answer is: All of the above
Q.109 Which type of stem cell is derived from the inner cell mass of the blastocyst?
Embryonic stem cell
Adult stem cell
Induced pluripotent stem cell
Mesenchymal stem cell
Explanation - ESCs arise from the inner cell mass and are pluripotent.
Correct answer is: Embryonic stem cell
Q.110 Which of the following is a key property of pluripotent stem cells?
Can differentiate into any cell type
Can only become blood cells
Do not divide
Are derived from adult tissues
Explanation - Pluripotent cells can give rise to all three germ layers.
Correct answer is: Can differentiate into any cell type
Q.111 Which of the following is a commonly used growth factor for neural stem cell expansion?
FGF-2
VEGF
PDGF
All of the above
Explanation - FGF-2 supports proliferation and maintenance of neural stem cells.
Correct answer is: FGF-2
Q.112 Which of the following is a major advantage of using synthetic polymers as scaffold materials?
They are biodegradable
They are easily sterilized
They allow precise control over degradation rate
All of the above
Explanation - Synthetic polymers can be engineered for desired properties, including biodegradability and sterilization.
Correct answer is: All of the above
Q.113 Which of the following is a potential risk of using stem cells in clinical therapy?
Tumorigenesis
Immune rejection
Infection
All of the above
Explanation - Stem cell therapies carry multiple risks, including tumor formation, rejection, and infection.
Correct answer is: All of the above
Q.114 Which of the following is a common method to produce iPSCs?
Transduction of Yamanaka factors
Differentiation from adult stem cells
Direct isolation from embryos
Chemical induction of somatic cells
Explanation - iPSCs are generated by introducing key transcription factors to reprogram adult cells.
Correct answer is: Transduction of Yamanaka factors
Q.115 Which of the following best describes a scaffold’s porosity?
The amount of space for cell infiltration
The amount of mechanical strength
The ability to degrade
The color of the scaffold
Explanation - Porosity determines how well cells can migrate into the scaffold and form tissues.
Correct answer is: The amount of space for cell infiltration
Q.116 Which of the following is a common application of stem cell therapy?
Treating heart disease
Regenerating cartilage
Repairing damaged nerve tissue
All of the above
Explanation - Stem cell therapy is being explored for multiple organ systems and tissue types.
Correct answer is: All of the above
Q.117 What is the main function of the extracellular matrix (ECM) in tissue engineering?
To provide a scaffold
To provide biochemical signals
To support cell adhesion and growth
All of the above
Explanation - ECM serves as a 3D support structure and delivers biochemical cues to cells.
Correct answer is: All of the above
Q.118 Which of the following is a characteristic of a mesenchymal stem cell?
It can differentiate into osteocytes
It expresses CD73, CD90, and CD105
It is derived from bone marrow
All of the above
Explanation - MSCs have multipotent differentiation capacity and specific surface markers.
Correct answer is: All of the above
Q.119 Which of the following is a key factor that promotes stem cell proliferation?
Low oxygen tension
High nutrient concentration
Mechanical stretch
All of the above
Explanation - Stem cells respond to a combination of biochemical and mechanical stimuli for proliferation.
Correct answer is: All of the above
Q.120 Which of the following is a common source of embryonic stem cells?
Embryonic day 6 blastocyst
Adult bone marrow
Dermal fibroblasts
All of the above
Explanation - ESCs are isolated from the inner cell mass of the blastocyst at around day 6.
Correct answer is: Embryonic day 6 blastocyst
Q.121 Which of the following best describes the role of oxygen concentration in stem cell culture?
High oxygen promotes stemness
Low oxygen promotes differentiation
Hypoxia mimics the stem cell niche and supports self-renewal
None of the above
Explanation - Stem cells often reside in low-oxygen environments; culturing them under hypoxia maintains stemness.
Correct answer is: Hypoxia mimics the stem cell niche and supports self-renewal
Q.122 Which of the following is an advantage of using iPSCs over ESCs?
Avoids ethical issues related to embryo destruction
They do not differentiate into all cell types
They are less prone to tumorigenesis
All of the above
Explanation - iPSCs are derived from adult cells and bypass the ethical concerns of ESCs.
Correct answer is: Avoids ethical issues related to embryo destruction
Q.123 Which of the following is NOT a characteristic of a scaffold used in regenerative medicine?
Biodegradability
Biocompatibility
Immunogenicity
Mechanical support
Explanation - Scaffolds should be non-immunogenic to avoid rejection.
Correct answer is: Immunogenicity
Q.124 What is a common method to evaluate the differentiation potential of stem cells?
Alkaline phosphatase staining
Immunohistochemistry for lineage-specific markers
Gene expression profiling
All of the above
Explanation - Multiple assays are used to confirm lineage-specific differentiation of stem cells.
Correct answer is: All of the above
Q.125 Which of the following is a major challenge when scaling up stem cell production for clinical use?
Maintaining cell quality and phenotype
Ensuring sterility
Reducing cost
All of the above
Explanation - Scale-up requires careful control of quality, sterility, and cost.
Correct answer is: All of the above
Q.126 Which of the following is a key characteristic of embryonic stem cells?
They are pluripotent
They can form teratomas in vivo
They are derived from the inner cell mass of blastocysts
All of the above
Explanation - ESCs are pluripotent, can form teratomas, and originate from blastocysts.
Correct answer is: All of the above
Q.127 Which of the following is a commonly used biomaterial for cartilage tissue engineering?
Alginate
Chitosan
Hydroxyapatite
All of the above
Explanation - Alginate and chitosan are popular hydrogel scaffolds; HA is used for bone but sometimes in cartilage constructs.
Correct answer is: All of the above
Q.128 Which of the following is a potential ethical concern in regenerative medicine?
Use of animal-derived products
Patient consent
Privacy of genetic data
All of the above
Explanation - Regenerative medicine raises multiple ethical issues regarding consent, animal use, and data privacy.
Correct answer is: All of the above
Q.129 Which of the following is an example of a growth factor used to induce bone formation?
BMP-2
VEGF
PDGF
All of the above
Explanation - Bone morphogenetic protein-2 promotes osteogenic differentiation of MSCs.
Correct answer is: BMP-2
Q.130 Which of the following is a common source of mesenchymal stem cells?
Bone marrow
Adipose tissue
Dental pulp
All of the above
Explanation - MSCs can be isolated from multiple adult tissues, including bone marrow, fat, and dental pulp.
Correct answer is: All of the above
Q.131 Which of the following is a major disadvantage of using embryonic stem cells?
Risk of tumor formation
Ethical controversies
Limited availability
All of the above
Explanation - ESCs raise ethical concerns, may form tumors, and are not readily available.
Correct answer is: All of the above
Q.132 What is the primary purpose of a scaffold in tissue engineering?
To provide a 3D structure for cell attachment
To deliver growth factors
Both A and B
None of the above
Explanation - Scaffolds serve as structural support and can release bioactive signals to guide tissue formation.
Correct answer is: Both A and B
Q.133 Which of the following is a key property of induced pluripotent stem cells?
They are derived from adult cells
They can differentiate into all cell types
They require reprogramming factors
All of the above
Explanation - iPSCs originate from adult cells and can become any cell type after reprogramming.
Correct answer is: All of the above
Q.134 Which of the following is a common method used to produce hydrogels for tissue engineering?
UV crosslinking
Chemical crosslinking
Thermal gelation
All of the above
Explanation - Hydrogels can be formed using various crosslinking techniques to create 3D matrices.
Correct answer is: All of the above
Q.135 Which of the following is a potential risk of using stem cells in regenerative medicine?
Tumor formation
Immune rejection
Infection
All of the above
Explanation - Stem cell therapies can lead to tumors, rejection, and infections if not carefully controlled.
Correct answer is: All of the above
Q.136 Which of the following is a typical application of stem cells in regenerative medicine?
Regenerating heart tissue
Repairing damaged bone
Treating diabetes with beta-cell replacement
All of the above
Explanation - Stem cells are explored for various regenerative applications across multiple organ systems.
Correct answer is: All of the above
Q.137 Which of the following is a characteristic of a scaffold that is useful for bone regeneration?
High porosity
Bioactive surface
Biodegradability
All of the above
Explanation - Effective bone scaffolds are porous, bioactive, and degrade to allow new bone formation.
Correct answer is: All of the above
Q.138 What is a key advantage of using hydrogels in tissue engineering?
They mimic the natural ECM
They can encapsulate cells and growth factors
They are easily shaped into complex geometries
All of the above
Explanation - Hydrogels provide a hydrated environment that supports cell growth and can be molded.
Correct answer is: All of the above
Q.139 Which of the following best describes the concept of 'stem cell niche'?
The microenvironment that controls stem cell behavior
The location of stem cells in the lab
The type of scaffold used for tissue engineering
The disease caused by stem cells
Explanation - The niche supplies signals that regulate self-renewal and differentiation of stem cells.
Correct answer is: The microenvironment that controls stem cell behavior
Q.140 Which of the following is an ethical concern associated with embryonic stem cell research?
Destruction of human embryos
Potential for genetic manipulation
High cost of research
All of the above
Explanation - ESC derivation involves destroying embryos, raising significant ethical debates.
Correct answer is: Destruction of human embryos
Q.141 Which of the following is a common use of mesenchymal stem cells?
Bone regeneration
Cartilage repair
All of the above
None of the above
Explanation - MSCs can differentiate into bone and cartilage cells and are widely used in regenerative medicine.
Correct answer is: All of the above
Q.142 Which of the following is a major advantage of using induced pluripotent stem cells over embryonic stem cells?
Avoids ethical concerns
Lower risk of tumor formation
Simpler reprogramming process
All of the above
Explanation - iPSCs are derived from adult cells, so they bypass the ethical issues surrounding ESCs.
Correct answer is: Avoids ethical concerns
Q.143 Which of the following is a commonly used biomaterial for skin tissue engineering?
Silk fibroin
Collagen
Hydroxyapatite
All of the above
Explanation - Silk fibroin, collagen, and hydroxyapatite can all be used as scaffolds for skin regeneration.
Correct answer is: All of the above
Q.144 What is the primary purpose of a scaffold in tissue engineering?
To provide a 3D structure for cell attachment
To deliver growth factors
Both A and B
None of the above
Explanation - Scaffolds serve as structural support and can release bioactive signals to guide tissue formation.
Correct answer is: Both A and B
Q.145 Which of the following best describes the role of mechanical forces in stem cell differentiation?
They have no effect on differentiation
They can influence lineage commitment
They only affect proliferation, not differentiation
None of the above
Explanation - Mechanical cues can direct stem cells toward specific tissue lineages (e.g., bone, muscle).
Correct answer is: They can influence lineage commitment
Q.146 Which of the following is a major challenge in using stem cells for regenerative medicine?
Risk of tumorigenesis
Immune rejection
Limited scalability
All of the above
Explanation - Stem cell therapies face multiple challenges, including safety, immune responses, and scale-up.
Correct answer is: All of the above
Q.147 What is the main difference between adult stem cells and embryonic stem cells?
Adult stem cells are pluripotent; ESCs are multipotent
Adult stem cells are multipotent; ESCs are pluripotent
Adult stem cells are totipotent; ESCs are pluripotent
No difference
Explanation - Adult stem cells can generate a limited set of cell types; ESCs can generate all embryonic lineages.
Correct answer is: Adult stem cells are multipotent; ESCs are pluripotent
Q.148 Which of the following is NOT a property of mesenchymal stem cells?
They can differentiate into osteoblasts
They express CD73, CD90, and CD105
They are derived from neural tissue
They have immunomodulatory properties
Explanation - MSCs are typically derived from bone marrow, fat, or other mesenchymal tissues, not neural tissue.
Correct answer is: They are derived from neural tissue
Q.149 Which of the following is a commonly used method for producing hydrogels for tissue engineering?
UV crosslinking
Chemical crosslinking
Thermal gelation
All of the above
Explanation - Hydrogels can be synthesized through various crosslinking methods to create a 3D matrix.
Correct answer is: All of the above
Q.150 Which of the following is a key factor that influences stem cell proliferation and differentiation?
Mechanical stimuli
Chemical signals
Temperature
All of the above
Explanation - Stem cell fate is regulated by a combination of mechanical, chemical, and thermal cues.
Correct answer is: All of the above
Q.151 Which of the following is a common source of embryonic stem cells?
Human blastocysts
Adult bone marrow
Skin fibroblasts
All of the above
Explanation - ESCs are isolated from the inner cell mass of human blastocysts.
Correct answer is: Human blastocysts
Q.152 What is the main purpose of a scaffold in tissue engineering?
To provide a 3D structure for cell attachment
To deliver growth factors
Both A and B
None of the above
Explanation - Scaffolds serve as structural support and can release bioactive signals to guide tissue formation.
Correct answer is: Both A and B
Q.153 Which of the following best describes the concept of 'stem cell niche'?
The microenvironment that controls stem cell behavior
The location of stem cells in the lab
The type of scaffold used for tissue engineering
The disease caused by stem cells
Explanation - The niche supplies signals that regulate self-renewal and differentiation of stem cells.
Correct answer is: The microenvironment that controls stem cell behavior
Q.154 Which of the following is a potential risk of using stem cells in regenerative medicine?
Tumor formation
Immune rejection
Infection
All of the above
Explanation - Stem cell therapies can lead to tumors, rejection, and infections if not carefully controlled.
Correct answer is: All of the above
Q.155 Which of the following is a commonly used scaffold material for cartilage tissue engineering?
Alginate
Chitosan
Hydroxyapatite
All of the above
Explanation - Alginate and chitosan are popular hydrogel scaffolds; HA is used for bone but sometimes in cartilage constructs.
Correct answer is: All of the above
Q.156 Which of the following is a key property of a scaffold used for bone regeneration?
High porosity
Bioactive surface
Biodegradability
All of the above
Explanation - Effective bone scaffolds are porous, bioactive, and degrade to allow new bone formation.
Correct answer is: All of the above
Q.157 Which of the following is a common application of stem cells in regenerative medicine?
Regenerating heart tissue
Repairing damaged bone
Treating diabetes with beta-cell replacement
All of the above
Explanation - Stem cells are explored for various regenerative applications across multiple organ systems.
Correct answer is: All of the above
Q.158 Which of the following is a common method used to produce hydrogels for tissue engineering?
UV crosslinking
Chemical crosslinking
Thermal gelation
All of the above
Explanation - Hydrogels can be synthesized through various crosslinking methods to create a 3D matrix.
Correct answer is: All of the above
Q.159 Which of the following is an advantage of using hydrogels in tissue engineering?
They mimic the natural ECM
They can encapsulate cells and growth factors
They are easily shaped into complex geometries
All of the above
Explanation - Hydrogels provide a hydrated environment that supports cell growth and can be molded.
Correct answer is: All of the above
Q.160 What is a major challenge in translating stem cell therapies to clinical use?
Ensuring cell safety and preventing tumorigenesis
Controlling immune responses
Scalability of cell production
All of the above
Explanation - Clinical translation must address safety, immune compatibility, and large-scale production.
Correct answer is: All of the above
Q.161 Which of the following is NOT a characteristic of mesenchymal stem cells?
They can differentiate into bone cells
They express CD73, CD90, and CD105
They are derived from neural tissue
They have immunomodulatory properties
Explanation - MSCs are typically derived from bone marrow, fat, or other mesenchymal tissues, not neural tissue.
Correct answer is: They are derived from neural tissue
Q.162 Which of the following is a major advantage of using induced pluripotent stem cells over embryonic stem cells?
Avoids ethical concerns
Lower risk of tumor formation
Simpler reprogramming process
All of the above
Explanation - iPSCs are derived from adult cells, so they bypass the ethical issues surrounding ESCs.
Correct answer is: Avoids ethical concerns
Q.163 Which of the following is a commonly used scaffold material for skin tissue engineering?
Silk fibroin
Collagen
Hydroxyapatite
All of the above
Explanation - Silk fibroin, collagen, and hydroxyapatite can all be used as scaffolds for skin regeneration.
Correct answer is: All of the above
Q.164 What is the main purpose of a scaffold in tissue engineering?
To provide a 3D structure for cell attachment
To deliver growth factors
Both A and B
None of the above
Explanation - Scaffolds serve as structural support and can release bioactive signals to guide tissue formation.
Correct answer is: Both A and B
Q.165 Which of the following best describes the role of mechanical forces in stem cell differentiation?
They have no effect on differentiation
They can influence lineage commitment
They only affect proliferation, not differentiation
None of the above
Explanation - Mechanical cues can direct stem cells toward specific tissue lineages (e.g., bone, muscle).
Correct answer is: They can influence lineage commitment
Q.166 Which of the following is a major challenge in using stem cells for regenerative medicine?
Risk of tumorigenesis
Immune rejection
Limited scalability
All of the above
Explanation - Stem cell therapies face multiple challenges, including safety, immune responses, and scale-up.
Correct answer is: All of the above