Q.1 What is the primary function of a scaffold in tissue engineering?
To deliver electrical signals
To provide a 3D framework for cell growth
To generate heat for cell metabolism
To remove waste products
Explanation - Scaffolds act as a temporary structural support that mimics the extracellular matrix, allowing cells to adhere, proliferate, and differentiate.
Correct answer is: To provide a 3D framework for cell growth
Q.2 Which of the following materials is commonly used as a biodegradable scaffold in bone tissue engineering?
Polylactic acid (PLA)
Polyethylene terephthalate (PET)
Polystyrene (PS)
Polypropylene (PP)
Explanation - PLA is a biodegradable polymer with suitable mechanical properties and biocompatibility for bone tissue scaffolds.
Correct answer is: Polylactic acid (PLA)
Q.3 In tissue engineering, what does the term 'bioreactor' refer to?
A device that stores biological samples at low temperatures
A system that provides controlled environmental conditions for cultured tissues
A type of scaffold material
An imaging technique for tissue analysis
Explanation - Bioreactors maintain optimal temperature, pH, oxygen, and mechanical stimuli to promote cell growth and tissue development.
Correct answer is: A system that provides controlled environmental conditions for cultured tissues
Q.4 Which growth factor is most critical for chondrogenesis in cartilage tissue engineering?
Vascular Endothelial Growth Factor (VEGF)
Bone Morphogenetic Protein 2 (BMP-2)
Transforming Growth Factor-beta (TGF-β)
Insulin-like Growth Factor 1 (IGF-1)
Explanation - TGF-β is essential for inducing mesenchymal stem cells to differentiate into chondrocytes, forming cartilage.
Correct answer is: Transforming Growth Factor-beta (TGF-β)
Q.5 What is a common method for delivering cells to a defect site in tissue engineering?
Direct injection of a cell suspension
Implantation of a cell-laden scaffold
Topical application of cell gel
All of the above
Explanation - All listed methods are employed depending on the tissue type and defect geometry.
Correct answer is: All of the above
Q.6 Which property is NOT typically considered when selecting a scaffold material?
Mechanical strength
Electrical conductivity
Biodegradability
Surface roughness
Explanation - While some engineered tissues require electrical cues, most scaffolds are chosen for mechanical, degradable, and surface properties rather than conductivity.
Correct answer is: Electrical conductivity
Q.7 The term 'recellularization' in tissue engineering refers to:
Removing cells from a scaffold
Reintroducing cells into a decellularized tissue matrix
Enhancing cell proliferation in a scaffold
Creating a new scaffold from scratch
Explanation - Recellularization involves seeding new cells onto a scaffold that has been cleared of original cells, preserving native extracellular matrix.
Correct answer is: Reintroducing cells into a decellularized tissue matrix
Q.8 What is the main advantage of using electrospun fibers in scaffold design?
High electrical conductivity
Large pore sizes
High surface area-to-volume ratio
Uniform thickness
Explanation - Electrospun nanofibers mimic the fibrous structure of native ECM, providing high surface area for cell attachment.
Correct answer is: High surface area-to-volume ratio
Q.9 Which imaging technique is most suitable for real-time monitoring of tissue-engineered constructs in vivo?
X-ray radiography
Magnetic Resonance Imaging (MRI)
Ultrasound imaging
Computed Tomography (CT)
Explanation - MRI provides high-resolution, non-ionizing imaging that can track the development of soft tissues over time.
Correct answer is: Magnetic Resonance Imaging (MRI)
Q.10 The term 'osteoconductive' refers to a scaffold property that:
Promotes bone cell apoptosis
Allows bone cells to migrate and grow along its surface
Inhibits new bone formation
Is electrically conductive
Explanation - Osteoconductive materials provide a physical framework that supports new bone tissue growth.
Correct answer is: Allows bone cells to migrate and grow along its surface
Q.11 Which cell type is most commonly used for engineering liver tissue?
Neural stem cells
Hepatocytes
Cardiomyocytes
Chondrocytes
Explanation - Hepatocytes are the primary functional cells of the liver, essential for metabolic and detoxification functions.
Correct answer is: Hepatocytes
Q.12 What is the purpose of adding growth factors to a bioreactor during tissue cultivation?
To sterilize the culture medium
To increase oxygen diffusion
To promote specific cell differentiation
To reduce nutrient consumption
Explanation - Growth factors guide stem cells toward desired lineages (e.g., osteogenic, chondrogenic) during engineering.
Correct answer is: To promote specific cell differentiation
Q.13 Which of the following is NOT a typical criterion for assessing tissue-engineered grafts before implantation?
Mechanical strength
Biocompatibility
Electrical resistance
Degradation rate
Explanation - While electrical properties matter for some tissues, mechanical strength, biocompatibility, and degradation are core assessment factors.
Correct answer is: Electrical resistance
Q.14 In cardiac tissue engineering, which stimulation technique is used to enhance tissue maturation?
Chemical stimulation with growth hormones
Electrical pacing
Magnetic field exposure
Ultrasonic waves
Explanation - Electrical cues mimic the heart’s natural rhythm, promoting alignment and functional coupling of cardiomyocytes.
Correct answer is: Electrical pacing
Q.15 The term 'angiogenesis' in tissue engineering refers to:
Formation of new bone
Development of blood vessels
Creation of cartilage
Generation of neuronal pathways
Explanation - Angiogenesis is critical for supplying oxygen and nutrients to engineered tissues, especially in large constructs.
Correct answer is: Development of blood vessels
Q.16 What is the most common source of mesenchymal stem cells (MSCs) for tissue engineering?
Bone marrow
Adipose tissue
Peripheral blood
All of the above
Explanation - MSCs can be harvested from bone marrow, fat, or blood, each source offering specific advantages.
Correct answer is: All of the above
Q.17 Which parameter is NOT directly controlled by a bioreactor during tissue cultivation?
Temperature
pH
Light intensity
Oxygen concentration
Explanation - Bioreactors regulate temperature, pH, oxygen, and sometimes shear stress, but light intensity is irrelevant for most tissue cultures.
Correct answer is: Light intensity
Q.18 The term 'bioink' is primarily associated with:
3D printing of tissue scaffolds
The delivery of genetic material to cells
The composition of the culture medium
The measurement of electrical conductivity
Explanation - Bioink contains living cells and biomaterials that can be printed into complex tissue structures.
Correct answer is: 3D printing of tissue scaffolds
Q.19 Which mechanical stimulus is most relevant for engineering bone tissue?
Compression
Shear
Torsion
All of the above
Explanation - Bone responds to various mechanical forces, and bioreactors often simulate compression, shear, or torsional loading.
Correct answer is: All of the above
Q.20 What is the role of decellularization in tissue engineering?
To remove cellular debris while preserving the extracellular matrix
To add cells to a scaffold
To sterilize the scaffold by heat
To increase scaffold porosity
Explanation - Decellularization creates a natural scaffold that retains ECM architecture but is devoid of immunogenic cells.
Correct answer is: To remove cellular debris while preserving the extracellular matrix
Q.21 Which of the following is a key challenge in engineering thick tissue constructs?
Insufficient nutrient diffusion
Excessive mechanical strength
Rapid degradation of scaffold
Inadequate cell proliferation
Explanation - In thicker tissues, cells at the core often become hypoxic because nutrients and oxygen cannot diffuse effectively.
Correct answer is: Insufficient nutrient diffusion
Q.22 The use of hydrogels in tissue engineering is mainly to:
Provide a stiff structural scaffold
Create a hydrated environment for cells
Serve as an electrical conduit
Act as a decellularization agent
Explanation - Hydrogels mimic the water-rich nature of native tissues, supporting cell viability and signaling.
Correct answer is: Create a hydrated environment for cells
Q.23 What is a major advantage of using induced pluripotent stem cells (iPSCs) in tissue engineering?
Unlimited proliferation capacity
Reduced ethical concerns compared to embryonic stem cells
Higher immunogenicity
They are readily available from blood samples
Explanation - iPSCs are derived from adult cells, avoiding the ethical issues surrounding embryonic stem cells.
Correct answer is: Reduced ethical concerns compared to embryonic stem cells
Q.24 Which of the following best describes 'mechanotransduction'?
The conversion of mechanical signals into biochemical responses by cells
The electrical stimulation of cells
The diffusion of nutrients through a scaffold
The chemical degradation of a biomaterial
Explanation - Mechanotransduction allows cells to sense and respond to mechanical forces, influencing differentiation and tissue formation.
Correct answer is: The conversion of mechanical signals into biochemical responses by cells
Q.25 Which of the following is NOT typically used as a biomaterial in cartilage tissue engineering?
Collagen
Alginate
Hydroxyapatite
Chondroitin sulfate
Explanation - Hydroxyapatite is primarily used for bone due to its mineral content, not cartilage.
Correct answer is: Hydroxyapatite
Q.26 The primary objective of vascular tissue engineering is to create:
Blood vessels that can integrate with host circulation
Cardiac muscle tissues
Lung alveoli
Neural networks
Explanation - Engineered blood vessels must be compliant, non-thrombogenic, and capable of withstanding blood flow pressures.
Correct answer is: Blood vessels that can integrate with host circulation
Q.27 In the context of tissue engineering, what does 'in vitro' mean?
Inside a living organism
In a controlled lab environment outside a living organism
In the bloodstream
In a computational model
Explanation - 'In vitro' refers to experiments performed in a controlled setting like a petri dish or bioreactor, not within a living organism.
Correct answer is: In a controlled lab environment outside a living organism
Q.28 What does the acronym 'MSCs' stand for in tissue engineering?
Muscle Stem Cells
Mammalian Stem Cells
Mesenchymal Stem Cells
Mitotic Stem Cells
Explanation - MSCs are multipotent stromal cells capable of differentiating into bone, cartilage, and fat tissues.
Correct answer is: Mesenchymal Stem Cells
Q.29 Which of the following is a benefit of using 3D bioprinting for tissue scaffolds?
Uniform pore sizes across the construct
Precise spatial control of cell placement
Reduced material cost
Increased electrical conductivity
Explanation - 3D bioprinting allows for accurate placement of cells and materials, creating complex tissue architectures.
Correct answer is: Precise spatial control of cell placement
Q.30 Which of these is a typical metric for evaluating scaffold porosity?
Surface roughness
Percent porosity
Electrical resistivity
Color index
Explanation - Porosity, expressed as a percentage of void space, determines cell infiltration and nutrient diffusion within scaffolds.
Correct answer is: Percent porosity
Q.31 The term 'bioactivity' in biomaterials refers to:
The ability to conduct electricity
The capacity to provoke a biological response
The rate of degradation
The mechanical stiffness
Explanation - A bioactive material interacts with biological tissues, often promoting bone bonding or cell attachment.
Correct answer is: The capacity to provoke a biological response
Q.32 Which cell type is used for engineering skin substitutes?
Keratinocytes
Osteoblasts
Neuroblasts
Adipocytes
Explanation - Keratinocytes form the outer epidermal layer of skin and are essential for skin grafts.
Correct answer is: Keratinocytes
Q.33 What does the 'ECM' stand for in tissue engineering?
Extracellular Matrix
Electrical Conductive Material
Epithelial Cell Maturation
Erythrocyte Cytokine Modulator
Explanation - The ECM is the complex network of proteins and polysaccharides that provides structural support to cells.
Correct answer is: Extracellular Matrix
Q.34 Which of these is NOT a typical application of tissue engineering?
Regeneration of damaged heart tissue
Creation of artificial bone for implants
Manufacturing of synthetic fuels
Development of engineered cartilage for joint repair
Explanation - Tissue engineering focuses on biological tissues, not energy production.
Correct answer is: Manufacturing of synthetic fuels
Q.35 What is a major limitation of using animal-derived collagen in human tissue constructs?
High cost
Risk of immune rejection
Lack of mechanical strength
Poor biodegradability
Explanation - Animal collagen can trigger immune responses in humans, limiting its clinical use.
Correct answer is: Risk of immune rejection
Q.36 In tissue engineering, 'mechanical conditioning' usually involves:
Applying electrical signals
Providing mechanical loads like compression or stretch
Adding growth factors
Using ultraviolet light
Explanation - Mechanical conditioning mimics the natural forces cells experience, enhancing tissue maturation.
Correct answer is: Providing mechanical loads like compression or stretch
Q.37 Which of these materials is known for its high electrical conductivity, useful for cardiac tissue engineering?
Polyethylene
Polycaprolactone
Gold nanoparticles
Silk fibroin
Explanation - Gold nanoparticles can conduct electricity, supporting synchronized cardiomyocyte contraction.
Correct answer is: Gold nanoparticles
Q.38 The 'spheroid' culture technique is often used in tissue engineering to:
Increase cell proliferation by providing a 3D environment
Create flat monolayers of cells
Eliminate the need for scaffolds
Generate electrical impulses
Explanation - Spheroids mimic in vivo 3D cell–cell interactions, improving differentiation.
Correct answer is: Increase cell proliferation by providing a 3D environment
Q.39 Which of the following is a key factor that determines the success of a tissue-engineered bone implant?
Electrical resistance
Porosity and interconnectivity of pores
Color of the scaffold
Vibration frequency of the bioreactor
Explanation - Adequate porosity allows for vascularization and bone ingrowth, crucial for implant integration.
Correct answer is: Porosity and interconnectivity of pores
Q.40 What is the main purpose of decellularized extracellular matrix (dECM) in tissue engineering?
To act as a drug delivery system
To serve as a natural scaffold that retains biological signals
To provide electrical conductivity
To replace all native cells in the tissue
Explanation - dECM retains growth factors and structural cues that promote cell attachment and differentiation.
Correct answer is: To serve as a natural scaffold that retains biological signals
Q.41 Which technique is commonly used to evaluate the mechanical properties of a scaffold?
Dynamic Mechanical Analysis (DMA)
Surface Plasmon Resonance
Atomic Force Microscopy
Mass Spectrometry
Explanation - DMA measures viscoelastic properties such as stiffness and damping in polymeric scaffolds.
Correct answer is: Dynamic Mechanical Analysis (DMA)
Q.42 Why are hydrogels often considered for soft tissue engineering?
They are rigid and strong
They have high water content and mimic soft tissues
They are electrically conductive
They are opaque to imaging
Explanation - Hydrogels replicate the hydrated nature of soft tissues like cartilage and skin.
Correct answer is: They have high water content and mimic soft tissues
Q.43 What does the 'seed density' refer to in tissue engineering?
Number of scaffold pores per unit area
Concentration of growth factors in the medium
Number of cells per unit volume of scaffold
Electrical charge of the scaffold surface
Explanation - Seed density determines how many cells are initially loaded onto a scaffold, affecting tissue development.
Correct answer is: Number of cells per unit volume of scaffold
Q.44 Which of these is an example of a natural polymer used in tissue scaffolds?
Polyethylene glycol (PEG)
Collagen
Polyacrylonitrile
Polystyrene
Explanation - Collagen is a naturally occurring protein abundant in the extracellular matrix.
Correct answer is: Collagen
Q.45 The term 'osteoinductive' describes a scaffold that:
Promotes bone cell migration
Induces stem cells to differentiate into osteoblasts
Is rigid
Is porous
Explanation - Osteoinductive materials actively stimulate bone formation by guiding cell differentiation.
Correct answer is: Induces stem cells to differentiate into osteoblasts
Q.46 In tissue engineering, why is the term 'bioprinting' preferred over '3D printing' when referring to cell-laden constructs?
It uses a different type of printer
It specifically involves printing living cells with biomaterials
It does not require sterilization
It is a marketing term
Explanation - Bioprinting refers to depositing living cells in precise patterns, while 3D printing can refer to non-living materials.
Correct answer is: It specifically involves printing living cells with biomaterials
Q.47 What is the main function of 'cell sheets' in tissue engineering?
To serve as a scaffold material
To provide a cell-dense, layered structure without a scaffold
To increase mechanical strength
To deliver electrical stimuli
Explanation - Cell sheets are harvested as intact layers, preserving cell–cell junctions and ECM for transplantation.
Correct answer is: To provide a cell-dense, layered structure without a scaffold
Q.48 Which of the following best describes 'vascularization' in engineered tissues?
The incorporation of blood vessels to supply oxygen and nutrients
The addition of growth factors to the scaffold
The electrical stimulation of tissues
The removal of cellular debris
Explanation - Vascularization enables long-term survival of cells within large engineered constructs.
Correct answer is: The incorporation of blood vessels to supply oxygen and nutrients
Q.49 What does 'biodegradability' of a scaffold material mean?
It can be broken down by the body over time
It is resistant to all forms of degradation
It can conduct electricity
It is completely inert
Explanation - Biodegradable scaffolds gradually degrade, allowing natural tissue to replace them.
Correct answer is: It can be broken down by the body over time
Q.50 Which technique can be used to align cells within a scaffold?
Magnetic fields
Shear flow in a bioreactor
Chemical gradients
All of the above
Explanation - Magnetic, mechanical, and chemical cues can be used to guide cell orientation.
Correct answer is: All of the above
Q.51 Which of the following is a typical indicator of successful osteogenesis in a culture?
Expression of alkaline phosphatase (ALP)
High lactate production
Low mineral deposition
Negative staining for osteocalcin
Explanation - ALP activity is an early marker of osteoblast differentiation and bone matrix formation.
Correct answer is: Expression of alkaline phosphatase (ALP)
Q.52 What is the primary concern when using non-degradable synthetic polymers in implants?
They degrade too quickly
They may cause long-term inflammation or require removal
They are too expensive
They are electrically conductive
Explanation - Non-degradable materials can provoke chronic immune responses and may need surgical removal.
Correct answer is: They may cause long-term inflammation or require removal
Q.53 Which of the following is an advantage of using decellularized heart tissue as a scaffold?
It contains native mechanical cues
It is inexpensive to produce
It eliminates the need for cell seeding
It guarantees 100% biocompatibility
Explanation - Decellularized hearts retain tissue architecture and mechanical properties that support cardiac cell function.
Correct answer is: It contains native mechanical cues
Q.54 What does the 'seed viability' assay measure?
The number of cells that survive after seeding onto a scaffold
The scaffold’s porosity
The degradation rate of the scaffold
The electrical activity of cells
Explanation - Viability assays (e.g., Live/Dead staining) determine how many cells remain alive post‑seeding.
Correct answer is: The number of cells that survive after seeding onto a scaffold
Q.55 Which of the following best describes 'myogenesis'?
Formation of bone tissue
Formation of nerve tissue
Formation of muscle tissue
Formation of skin tissue
Explanation - Myogenesis is the developmental process by which muscle cells and fibers form.
Correct answer is: Formation of muscle tissue
Q.56 What is the purpose of using a 'dynamic' bioreactor rather than a static one?
To maintain constant temperature
To provide mechanical stimuli such as shear stress
To increase scaffold porosity
To reduce nutrient diffusion
Explanation - Dynamic systems mimic the physiological forces cells experience, improving tissue maturation.
Correct answer is: To provide mechanical stimuli such as shear stress
Q.57 Which of the following is a challenge associated with the scale‑up of tissue-engineered constructs for clinical use?
Maintaining uniform cell distribution
Ensuring consistent mechanical properties
Controlling sterility over large volumes
All of the above
Explanation - Large-scale production must address cell distribution, mechanical uniformity, and sterility.
Correct answer is: All of the above
Q.58 What is the primary role of 'growth factor delivery systems' in tissue engineering?
To kill unwanted cells
To release growth factors in a controlled manner to guide differentiation
To increase scaffold stiffness
To provide electrical signals
Explanation - Delivery systems (e.g., microparticles) enable localized, sustained release of bioactive molecules.
Correct answer is: To release growth factors in a controlled manner to guide differentiation
Q.59 Which technique is used to assess cell infiltration depth within a scaffold?
Scanning Electron Microscopy (SEM)
Confocal Microscopy
Transmission Electron Microscopy (TEM)
X-ray diffraction
Explanation - Confocal imaging can produce optical sections, revealing how deep cells have penetrated the scaffold.
Correct answer is: Confocal Microscopy
Q.60 In bone tissue engineering, a 'dual‑release' system typically releases:
Two growth factors at different rates
One growth factor twice
Two scaffolds simultaneously
Two cell types sequentially
Explanation - Dual‑release systems sequentially release factors (e.g., VEGF then BMP-2) to mimic natural bone healing.
Correct answer is: Two growth factors at different rates
Q.61 Why is oxygen tension important in tissue culture?
It influences cell metabolism and differentiation
It changes scaffold color
It determines scaffold size
It controls nutrient concentration
Explanation - Low oxygen (hypoxia) can promote stem cell self‑renewal, while normoxia may enhance differentiation.
Correct answer is: It influences cell metabolism and differentiation
Q.62 Which of these is a key feature of a 'biomimetic' scaffold?
It has a synthetic polymer composition
It replicates the physical and chemical cues of natural ECM
It is designed for electrical conduction only
It is made of metal
Explanation - Biomimetic scaffolds aim to emulate the native tissue’s environment for better integration.
Correct answer is: It replicates the physical and chemical cues of natural ECM
Q.63 Which of the following is a non‑cellular strategy to enhance tissue regeneration?
Mechanical loading
Electrical stimulation
Bioreactor culture
All of the above
Explanation - Non‑cellular cues like mechanical, electrical, and dynamic culture conditions can influence cell behavior.
Correct answer is: All of the above
Q.64 Which of the following best describes a 'composite scaffold'?
A scaffold composed of multiple cell types
A scaffold made from a blend of materials to combine properties
A scaffold with electrical conductors embedded
A scaffold that is entirely natural
Explanation - Composites combine natural and synthetic components to achieve desired mechanical and biological characteristics.
Correct answer is: A scaffold made from a blend of materials to combine properties
Q.65 What is the primary function of 'osteoclasts' in bone remodeling?
They form new bone tissue
They break down bone tissue
They transport calcium
They act as stem cells
Explanation - Osteoclasts resorb bone, allowing remodeling and repair.
Correct answer is: They break down bone tissue
Q.66 In tissue engineering, which of these is a characteristic of a 'bioactive glass' scaffold?
It is biodegradable and promotes bone bonding
It conducts electricity
It is made from polymers
It is non‑biodegradable
Explanation - Bioactive glass releases ions that stimulate bone formation and integrates with native bone.
Correct answer is: It is biodegradable and promotes bone bonding
Q.67 What is the advantage of using microfluidic bioreactors in tissue engineering?
They allow high throughput of samples
They can provide precise fluid flow and gradient control
They are less expensive than traditional bioreactors
All of the above
Explanation - Microfluidics enable fine control over shear stress, chemical gradients, and nutrient delivery.
Correct answer is: They can provide precise fluid flow and gradient control
Q.68 What does the term 'implantable device' refer to in the context of tissue engineering?
A non‑invasive imaging tool
An external mechanical stimulator
A device that can be implanted in the body to support tissue growth
A chemical reagent
Explanation - Implantable devices may serve as scaffolds, drug delivery systems, or functional implants.
Correct answer is: A device that can be implanted in the body to support tissue growth
Q.69 Which of the following best describes the 'seed‑scaffold ratio'?
The ratio of cells to scaffold material weight
The ratio of scaffold surface area to cell number
The ratio of scaffold porosity to cell viability
The ratio of growth factors to cells
Explanation - This ratio determines how many cells are available per available attachment area, impacting colonization.
Correct answer is: The ratio of scaffold surface area to cell number
Q.70 In cartilage tissue engineering, 'chondrogenesis' primarily requires:
High oxygen levels
Low oxygen levels and TGF‑β stimulation
Electrical stimulation
High shear stress
Explanation - Cartilage is avascular; hypoxic conditions and TGF‑β promote chondrocyte differentiation.
Correct answer is: Low oxygen levels and TGF‑β stimulation
Q.71 Which of the following is a key marker for mesenchymal stem cell differentiation into adipocytes?
Collagen type I
Peroxisome proliferator-activated receptor gamma (PPARγ)
Alkaline phosphatase
Osteocalcin
Explanation - PPARγ is a transcription factor essential for adipogenic differentiation.
Correct answer is: Peroxisome proliferator-activated receptor gamma (PPARγ)
Q.72 Which of the following best describes a 'hydrogel'?
A porous solid polymer
A water‑swollen, cross‑linked polymer network
A metallic scaffold
A biodegradable composite
Explanation - Hydrogels retain large amounts of water, resembling soft tissue environments.
Correct answer is: A water‑swollen, cross‑linked polymer network
Q.73 What is the main limitation of using pure polymeric scaffolds for bone tissue engineering?
They are too stiff
They do not support vascularization
They degrade too quickly
They lack electrical conductivity
Explanation - Polymer scaffolds often lack the necessary porosity and cues for blood vessel ingrowth.
Correct answer is: They do not support vascularization
Q.74 In tissue engineering, why is 'surface functionalization' of scaffolds important?
To improve mechanical strength
To enhance cell adhesion and signaling
To increase electrical conductivity
To reduce scaffold cost
Explanation - Functional groups like RGD peptides improve integrin binding and cell attachment.
Correct answer is: To enhance cell adhesion and signaling
Q.75 Which of the following is an example of a 'bioinspired' material for tissue scaffolding?
Polylactic acid (PLA)
Silk fibroin
Graphite
Glass fiber
Explanation - Silk fibroin is derived from natural silk, exhibiting desirable mechanical and biocompatible properties.
Correct answer is: Silk fibroin
Q.76 What is the significance of 'interconnectivity' in scaffold design?
It ensures uniform electrical conduction
It allows cells to migrate throughout the scaffold
It reduces material cost
It provides mechanical stiffness
Explanation - Interconnected pores enable nutrient diffusion and cell infiltration, vital for tissue growth.
Correct answer is: It allows cells to migrate throughout the scaffold
Q.77 Which of the following best describes a 'cage' system in bioreactor design?
A hollow structure that holds the scaffold for dynamic culture
A container that stores growth media
A device that measures electrical activity
A filtration unit
Explanation - Cages allow scaffolds to be moved or rotated to provide uniform mechanical stimuli.
Correct answer is: A hollow structure that holds the scaffold for dynamic culture
Q.78 Which parameter is most critical to assess when evaluating the osteogenic potential of a scaffold?
Electrical resistance
Surface roughness
Release profile of calcium ions
Porosity
Explanation - Calcium ion release can stimulate osteogenic differentiation and mineralization.
Correct answer is: Release profile of calcium ions
Q.79 The term 'neurogenesis' refers to:
Formation of new blood vessels
Formation of new neurons
Formation of cartilage
Formation of bone
Explanation - Neurogenesis is the process by which new neurons are generated, especially in the brain.
Correct answer is: Formation of new neurons
Q.80 Which of the following is a primary challenge for vascular tissue engineering?
Achieving smooth muscle cell alignment
Creating a porous scaffold
Increasing scaffold stiffness
Reducing scaffold cost
Explanation - Proper alignment of smooth muscle cells is crucial for vessel contractility and function.
Correct answer is: Achieving smooth muscle cell alignment
Q.81 What is the advantage of using a 'dual‑phase' scaffold for bone and cartilage repair?
It mimics the natural transition between bone and cartilage
It reduces material cost
It eliminates the need for growth factors
It is easier to manufacture
Explanation - A dual‑phase scaffold can provide distinct environments for bone and cartilage tissue formation.
Correct answer is: It mimics the natural transition between bone and cartilage
Q.82 Which of the following best describes 'in situ tissue engineering'?
Engineering tissue outside the body and implanting it
Stimulating the body’s own cells to regenerate tissue at the defect site
Using a scaffold that dissolves instantly
Using a synthetic polymer only
Explanation - In situ engineering leverages the body’s natural regenerative capacity with minimally invasive devices.
Correct answer is: Stimulating the body’s own cells to regenerate tissue at the defect site
Q.83 Which imaging modality is most suitable for visualizing the distribution of cells within a thick 3D scaffold?
Optical coherence tomography (OCT)
MRI
Ultrasound
X-ray micro‑CT
Explanation - MRI can penetrate deep into tissue constructs and provide high contrast for labeled cells.
Correct answer is: MRI
Q.84 In tissue engineering, why is 'mechanical preconditioning' sometimes applied before implantation?
To sterilize the construct
To align collagen fibers and increase mechanical strength
To remove excess cells
To increase degradation rate
Explanation - Preconditioning can improve the mechanical properties and orientation of the engineered tissue.
Correct answer is: To align collagen fibers and increase mechanical strength
Q.85 Which of the following is a typical feature of a 'living scaffold'?
It contains embedded live cells or biologically active molecules
It is fully synthetic
It has no pores
It is inert
Explanation - Living scaffolds provide immediate biological cues for tissue regeneration.
Correct answer is: It contains embedded live cells or biologically active molecules
Q.86 Which of these is a common method for sterilizing tissue-engineered constructs?
Gamma irradiation
Ultraviolet light
Ethylene oxide gas
All of the above
Explanation - All listed methods are used depending on material compatibility and sterility requirements.
Correct answer is: All of the above
Q.87 What does the 'biological equivalent' of a scaffold refer to?
The scaffold that is exactly the same material as natural tissue
The scaffold that mimics the structure and function of natural ECM
A scaffold with no pores
A scaffold made only of metals
Explanation - A biological equivalent reproduces the native tissue’s environment for cells.
Correct answer is: The scaffold that mimics the structure and function of natural ECM
Q.88 Which of the following is a key factor influencing the degradation rate of a biodegradable polymer scaffold?
Molecular weight
Crystallinity
Hydrophobicity
All of the above
Explanation - All listed properties affect how quickly the polymer degrades in physiological conditions.
Correct answer is: All of the above
Q.89 Which of the following best describes 'cell–cell interaction' in tissue engineering?
Interaction between different scaffold materials
Interaction between cells that influences differentiation and function
Interaction between the scaffold and the implant
Interaction between nutrients and cells
Explanation - Cell–cell communication is crucial for tissue organization and maturation.
Correct answer is: Interaction between cells that influences differentiation and function
Q.90 What is the primary purpose of using 'bioactive ceramics' in bone tissue engineering?
To provide electrical signals
To release growth factors slowly
To stimulate bone formation and bond with bone tissue
To act as a drug carrier only
Explanation - Bioactive ceramics like calcium phosphates promote bone bonding and integration.
Correct answer is: To stimulate bone formation and bond with bone tissue
Q.91 Which of the following is a challenge associated with cell-based therapies in tissue engineering?
Cell source variability
Immunogenic rejection
Scaffold degradation
All of the above
Explanation - Variability in cell sources and immune responses, along with scaffold degradation, affect therapy outcomes.
Correct answer is: All of the above
Q.92 In tissue engineering, what is the role of 'matrix metalloproteinases' (MMPs)?
They inhibit scaffold degradation
They facilitate remodeling of the extracellular matrix
They act as growth factors
They provide electrical signals
Explanation - MMPs are enzymes that degrade ECM components, allowing tissue remodeling and integration.
Correct answer is: They facilitate remodeling of the extracellular matrix
Q.93 Which of the following best describes 'in vivo' studies?
Experiments conducted outside a living organism
Experiments performed inside a living organism
Computer simulations
Cell culture in a petri dish
Explanation - 'In vivo' refers to studies performed within a living system, such as animal models.
Correct answer is: Experiments performed inside a living organism
Q.94 What does the term 'bioprinting resolution' refer to?
The thickness of the printed scaffold layers
The spatial accuracy of cell placement
The speed of the printing process
The electrical conductivity of the printed material
Explanation - Resolution describes how finely the printer can position cells and materials.
Correct answer is: The spatial accuracy of cell placement
Q.95 Which of the following is a typical outcome measured to confirm successful chondrogenesis?
Alkaline phosphatase activity
Cartilage proteoglycan content (e.g., safranin O staining)
Osteocalcin expression
Calcium deposition
Explanation - Proteoglycans are key components of cartilage matrix, indicating successful chondrogenic differentiation.
Correct answer is: Cartilage proteoglycan content (e.g., safranin O staining)
Q.96 Which of the following best describes a 'bioresorbable' polymer?
A polymer that dissolves in water only
A polymer that can be degraded by bodily enzymes or hydrolysis
A polymer that resists all forms of degradation
A polymer that is electrically conductive
Explanation - Bioresorbable polymers break down into non‑toxic by‑products within the body.
Correct answer is: A polymer that can be degraded by bodily enzymes or hydrolysis
Q.97 Which of these factors is most critical for ensuring cell viability during long‑term culture in a bioreactor?
Stable temperature control
Consistent nutrient supply
Appropriate mechanical stimulation
All of the above
Explanation - Temperature, nutrients, and mechanical cues all influence long‑term cell health.
Correct answer is: All of the above
Q.98 What does the acronym '3D' stand for in bioprinting?
Three-dimensional
Three-dimensional printing
Three-dimensional growth
Three‑dimensional scaffold
Explanation - '3D' refers to structures that have depth in addition to length and width.
Correct answer is: Three-dimensional
Q.99 Which of the following is NOT typically a component of a cell-laden bioink?
Cells
Biomaterial polymers
Growth factors
Metallic nanoparticles
Explanation - While metallic nanoparticles can be used for imaging or electrical purposes, they are not standard components of most bioinks.
Correct answer is: Metallic nanoparticles
Q.100 Which of the following best describes 'mechanical compliance' of a scaffold?
Its resistance to electrical stimulation
Its ability to deform under load similar to native tissue
Its rate of biodegradation
Its surface roughness
Explanation - Compliance ensures the scaffold can move with the surrounding tissue, reducing stress concentration.
Correct answer is: Its ability to deform under load similar to native tissue
Q.101 In cartilage tissue engineering, which material is often chosen for its ability to form a gel-like hydrogel?
Polyethylene
Alginate
Polystyrene
Titanium
Explanation - Alginate gels upon exposure to calcium ions, creating a supportive environment for chondrocytes.
Correct answer is: Alginate
Q.102 What is the purpose of 'passive perfusion' in a bioreactor?
To maintain sterility
To provide mechanical stimulation by fluid flow
To sterilize the scaffold
To reduce scaffold porosity
Explanation - Passive perfusion supplies nutrients and shear stress without active pumping.
Correct answer is: To provide mechanical stimulation by fluid flow
Q.103 Which of the following is a typical method to assess cell proliferation within a scaffold?
MTT assay
Alizarin red staining
Von Kossa staining
Alkaline phosphatase assay
Explanation - MTT measures metabolic activity, which correlates with cell number.
Correct answer is: MTT assay
Q.104 What is the significance of 'matrix stiffness' for stem cell differentiation?
It has no effect on differentiation
Stiffer matrices tend to promote osteogenic differentiation
Softer matrices promote neural differentiation
Both B and C
Explanation - Matrix stiffness directs stem cells: stiff environments favor bone; softer ones favor nerve cells.
Correct answer is: Both B and C
Q.105 Which of the following is an advantage of using a 'dynamic' culture system over a static one?
Simpler design
Reduced nutrient diffusion
Enhanced mass transport and mechanical stimulation
Lower cost
Explanation - Dynamic systems improve oxygen and nutrient delivery while providing mechanical cues.
Correct answer is: Enhanced mass transport and mechanical stimulation
Q.106 Which of these is a common method to promote vascularization in engineered tissues?
Addition of pro‑angiogenic factors like VEGF
Increasing scaffold stiffness
Using non‑porous materials
Reducing oxygen supply
Explanation - VEGF stimulates endothelial cell proliferation and blood vessel formation.
Correct answer is: Addition of pro‑angiogenic factors like VEGF
Q.107 What is the primary benefit of using 'biomimetic' surfaces for cell attachment?
They increase scaffold strength
They reduce immune response
They provide specific ligand motifs that promote integrin binding
They eliminate the need for growth factors
Explanation - Surface motifs like RGD enhance cell adhesion and signaling.
Correct answer is: They provide specific ligand motifs that promote integrin binding
Q.108 Which of the following is a common metric for evaluating the mechanical strength of a scaffold?
Compression modulus
Viscosity
Fluorescence intensity
Color change
Explanation - The compression modulus quantifies a material’s resistance to compression.
Correct answer is: Compression modulus
Q.109 Which of these is NOT typically a component of a 'bioink' formulation?
Cells
Crosslinker
Growth factor
Photocrosslinkable polymer
Explanation - While growth factors may be included, they are not always part of the base bioink formulation.
Correct answer is: Growth factor
Q.110 What is the main advantage of using 'hydroxyapatite' in bone tissue engineering?
It is electrically conductive
It mimics bone mineral content and promotes bone bonding
It is a polymer
It has low mechanical strength
Explanation - Hydroxyapatite is chemically similar to bone mineral, facilitating integration.
Correct answer is: It mimics bone mineral content and promotes bone bonding
Q.111 What does the 'seed cell density' parameter influence in a tissue-engineered construct?
Scaffold stiffness
Cellular colonization and tissue formation
Scaffold degradation rate
Electrical conductivity
Explanation - Higher densities can promote faster tissue formation but may also lead to hypoxia if too high.
Correct answer is: Cellular colonization and tissue formation
Q.112 In the context of tissue engineering, what does 'osteo‑osteogenic' refer to?
Scaffold that supports bone and bone marrow
Scaffold that promotes cartilage formation
Scaffold that provides electrical stimuli
Scaffold that resists bone integration
Explanation - Osteogenic scaffolds facilitate both bone formation and marrow development.
Correct answer is: Scaffold that supports bone and bone marrow
Q.113 Which of the following is a common challenge when scaling up bioreactor systems for tissue production?
Maintaining uniform temperature gradients
Ensuring consistent cell seeding across large volumes
Managing shear stress distribution
All of the above
Explanation - Large-scale bioreactors must address temperature, seeding uniformity, and shear stress control.
Correct answer is: All of the above
Q.114 What does the term 'extracellular vesicle' (EV) refer to?
A small, membrane-bound particle released by cells
A type of scaffold
A growth factor
A bioreactor component
Explanation - EVs carry signaling molecules and can modulate cell behavior in tissue engineering.
Correct answer is: A small, membrane-bound particle released by cells
Q.115 Which of the following is an essential component of the scaffold design for cardiac tissue engineering?
High electrical conductivity
High mechanical stiffness
Large pore size
Low porosity
Explanation - Electrical conductivity supports coordinated cardiomyocyte contraction.
Correct answer is: High electrical conductivity
Q.116 In tissue engineering, why is 'surface topography' of a scaffold important?
It affects the scaffold’s color
It influences cell adhesion and orientation
It changes the scaffold’s weight
It determines the scaffold’s electrical conductivity
Explanation - Micro‑ and nanoscale features guide cell behavior and tissue organization.
Correct answer is: It influences cell adhesion and orientation
Q.117 What is the purpose of 'pre‑vascularization' of a scaffold before implantation?
To provide immediate blood supply after implantation
To reduce scaffold degradation
To increase mechanical strength
To sterilize the construct
Explanation - Pre‑vascularized scaffolds have built‑in vessels that quickly connect to host vasculature.
Correct answer is: To provide immediate blood supply after implantation
Q.118 Which of the following best defines 'cell seeding density' in tissue engineering?
The ratio of scaffold volume to cell number
The number of cells per unit area of scaffold surface
The number of cells per scaffold pore
Both A and B
Explanation - Cell seeding density is typically expressed as cells per area or per volume of scaffold.
Correct answer is: Both A and B
Q.119 Which of the following is an advantage of using 'nanoparticles' in tissue engineering?
They increase scaffold stiffness
They can deliver drugs or growth factors
They replace cells entirely
They are always biodegradable
Explanation - Nanoparticles serve as carriers for controlled release of bioactive molecules.
Correct answer is: They can deliver drugs or growth factors
Q.120 What is the main reason for incorporating 'crosslinking agents' in hydrogel scaffolds?
To reduce porosity
To increase scaffold stiffness and stability
To eliminate cell attachment
To increase degradation rate
Explanation - Crosslinking forms a 3D network that stabilizes the hydrogel structure.
Correct answer is: To increase scaffold stiffness and stability
Q.121 Which of the following is a commonly used animal model for evaluating vascular grafts?
Mouse
Rabbit
Pig
All of the above
Explanation - Different species offer varying scales and physiological relevance for vascular studies.
Correct answer is: All of the above
Q.122 Which of the following best describes 'electrospinning'?
A method to deposit cells onto a scaffold
A process to create nano‑to‑micro fibers from polymers
A type of bioreactor
An imaging technique
Explanation - Electrospinning uses an electric field to draw polymer solutions into fine fibers.
Correct answer is: A process to create nano‑to‑micro fibers from polymers
Q.123 Which of the following is an example of a 'synthetic polymer' used in tissue engineering?
Collagen
Polycaprolactone (PCL)
Gelatin
Chitosan
Explanation - PCL is a synthetic, biodegradable polymer widely used for scaffolds.
Correct answer is: Polycaprolactone (PCL)
Q.124 What does the term 'in situ' refer to in tissue engineering?
Cell culture performed in a lab dish
Engineering that takes place within the body
Use of a scaffold in a test tube
A type of imaging method
Explanation - In situ approaches harness the body's own regenerative capacity.
Correct answer is: Engineering that takes place within the body
Q.125 Which of these is a key consideration when selecting a growth factor for bone tissue engineering?
Its molecular weight
Its ability to promote osteogenic differentiation
Its color
Its electrical conductivity
Explanation - The growth factor must specifically induce stem cells to become bone-forming cells.
Correct answer is: Its ability to promote osteogenic differentiation
Q.126 Which of the following is a common technique for measuring cell infiltration depth?
Confocal microscopy
X-ray diffraction
Surface profilometry
Thermal gravimetric analysis
Explanation - Confocal imaging can create optical sections through the scaffold to visualize cell distribution.
Correct answer is: Confocal microscopy
Q.127 What is the role of 'bioprinter nozzle diameter' in biofabrication?
It determines the speed of printing
It affects the resolution and viability of printed cells
It influences scaffold stiffness
It controls nutrient diffusion
Explanation - Smaller nozzle diameters increase resolution but may shear cells during extrusion.
Correct answer is: It affects the resolution and viability of printed cells
Q.128 Which of the following is a typical property of a 'bioactive ceramic'?
It dissolves in water only
It releases calcium and phosphate ions to stimulate bone growth
It is metallic
It is non‑degradable
Explanation - Bioactive ceramics promote bone bonding by releasing bioactive ions.
Correct answer is: It releases calcium and phosphate ions to stimulate bone growth
Q.129 What is a common method to enhance the mechanical properties of a polymer scaffold?
Blending with ceramics
Increasing polymer chain length
Adding surfactants
Reducing porosity
Explanation - Incorporating ceramics like hydroxyapatite can increase stiffness and strength.
Correct answer is: Blending with ceramics
Q.130 Which of these is a typical function of 'vascular endothelial growth factor (VEGF)' in tissue engineering?
Promoting bone mineralization
Stimulating angiogenesis
Inhibiting cell proliferation
Increasing scaffold stiffness
Explanation - VEGF encourages formation of new blood vessels, crucial for tissue survival.
Correct answer is: Stimulating angiogenesis
Q.131 In cartilage tissue engineering, 'safranin O' staining is used to detect:
Mineralized matrix
Proteoglycan content
Alkaline phosphatase activity
Collagen type I
Explanation - Safranin O binds to glycosaminoglycans, indicating cartilage matrix.
Correct answer is: Proteoglycan content
Q.132 Which of the following best describes 'electroconductive scaffolds'?
Scaffolds that provide a conductive pathway for electrical signals
Scaffolds that are transparent
Scaffolds that degrade rapidly
Scaffolds that are purely polymeric
Explanation - Electroconductive scaffolds are used in tissues requiring electrical cues, such as muscle and nerve.
Correct answer is: Scaffolds that provide a conductive pathway for electrical signals
Q.133 What is the main advantage of using 'bioprinted' constructs over traditional scaffold fabrication?
They are cheaper to produce
They allow precise spatial control of cells and materials
They require no sterile conditions
They do not need bioreactors
Explanation - Bioprinting can place multiple cell types and materials in defined architectures.
Correct answer is: They allow precise spatial control of cells and materials
Q.134 In tissue engineering, what does 'spheroid formation' refer to?
The creation of 3D cell aggregates
The layering of cells into sheets
The deposition of cells onto a scaffold surface
The mixing of cells with hydrogels
Explanation - Spheroids are spherical cell aggregates that better mimic in‑vivo cell interactions.
Correct answer is: The creation of 3D cell aggregates
Q.135 Which of the following is a key requirement for a material used as a scaffold in neural tissue engineering?
High electrical conductivity
High mechanical stiffness
High porosity
Low surface roughness
Explanation - Neural tissues benefit from conductive materials that support signal propagation.
Correct answer is: High electrical conductivity
Q.136 What does the term 'pore interconnectivity' mean in the context of a scaffold?
The pores are all the same size
The pores are connected, allowing fluid flow throughout the scaffold
The scaffold has no pores
The pores are isolated from one another
Explanation - Interconnected pores ensure nutrients and cells can travel throughout the scaffold.
Correct answer is: The pores are connected, allowing fluid flow throughout the scaffold
Q.137 Which of the following is a typical method for fabricating porous scaffolds?
Melt extrusion
Salt leaching
Electrospinning
All of the above
Explanation - Each method can create porous structures suitable for tissue engineering.
Correct answer is: All of the above
Q.138 What is the main purpose of incorporating 'nano‑silica' particles into a polymer scaffold?
To improve electrical conductivity
To enhance mechanical strength and bioactivity
To reduce the scaffold’s cost
To increase pore size
Explanation - Nano‑silica can reinforce the matrix and provide bioactive surface sites.
Correct answer is: To enhance mechanical strength and bioactivity
Q.139 Which of the following is a typical use of a 'dual‑release' system in bone tissue engineering?
To release a drug and a scaffold material simultaneously
To release growth factors in a sequential manner (e.g., VEGF then BMP‑2)
To deliver electrical impulses and chemicals
To release cells and scaffold together
Explanation - Sequential release mimics natural healing stages, first angiogenesis then bone formation.
Correct answer is: To release growth factors in a sequential manner (e.g., VEGF then BMP‑2)
Q.140 Which of these is a common method to evaluate cell viability after seeding on a scaffold?
Live/Dead assay using calcein AM and propidium iodide
Alizarin red staining
Alkaline phosphatase assay
Von Kossa staining
Explanation - This assay distinguishes live (green) from dead (red) cells via fluorescence.
Correct answer is: Live/Dead assay using calcein AM and propidium iodide
Q.141 Which of the following is a common advantage of using a 'hydrogel' scaffold in cartilage tissue engineering?
It provides high mechanical stiffness
It mimics the water‑rich environment of cartilage
It is electrically conductive
It is non‑biodegradable
Explanation - Hydrogels replicate cartilage’s high water content, supporting chondrocyte viability.
Correct answer is: It mimics the water‑rich environment of cartilage
Q.142 In tissue engineering, what does the term 'pre‑seeded scaffold' refer to?
A scaffold that has been sterilized before seeding
A scaffold that has been seeded with cells prior to implantation
A scaffold that has no cells but contains growth factors
A scaffold that has been crosslinking before seeding
Explanation - Pre‑seeded scaffolds contain living cells to accelerate tissue formation after implantation.
Correct answer is: A scaffold that has been seeded with cells prior to implantation
Q.143 Which of the following is a typical marker for osteogenic differentiation?
Alkaline phosphatase (ALP)
Collagen type II
Sox9
Nestin
Explanation - ALP is an early marker of osteoblast activity during bone formation.
Correct answer is: Alkaline phosphatase (ALP)
Q.144 Which of these is a benefit of using '3D porous scaffolds' for tissue engineering?
Reduced surface area
Enhanced cell infiltration and nutrient diffusion
Lower mechanical strength
Increased scaffold density
Explanation - Porosity allows cells and fluids to penetrate deeper into the scaffold.
Correct answer is: Enhanced cell infiltration and nutrient diffusion
Q.145 What does 'osteoconductive' refer to in bone tissue engineering?
The scaffold’s ability to promote bone growth by providing a physical framework
The scaffold’s ability to inhibit bone formation
The scaffold’s electrical conductivity
The scaffold’s high degradation rate
Explanation - Osteoconductive materials guide new bone tissue to grow along their surface.
Correct answer is: The scaffold’s ability to promote bone growth by providing a physical framework
Q.146 Which of the following is a common technique used to assess mechanical properties of tissue‑engineered constructs?
Compression testing
Electrical impedance spectroscopy
Mass spectrometry
X-ray crystallography
Explanation - Compression tests measure the force required to compress a scaffold, indicating stiffness.
Correct answer is: Compression testing
Q.147 Which of the following is NOT typically a component of a 'bioactive scaffold'?
Growth factor
Electrical stimulus
Biocompatible polymer
Immunogenic protein
Explanation - Bioactive scaffolds aim to minimize immune response, not provoke it.
Correct answer is: Immunogenic protein
Q.148 What is the main purpose of a 'bioreactor' in tissue engineering?
To store tissue constructs at room temperature
To provide a controlled environment for tissue growth and maturation
To sterilize the scaffold
To deliver electrical stimuli only
Explanation - Bioreactors regulate temperature, pH, oxygen, and mechanical forces for optimal tissue development.
Correct answer is: To provide a controlled environment for tissue growth and maturation
Q.149 Which of the following best describes a 'vascularized' tissue construct?
A construct lacking blood vessels
A construct that contains a pre‑formed network of blood vessels
A construct that is fully dehydrated
A construct that is purely polymeric
Explanation - Vascularized constructs have built‑in vessels to improve nutrient delivery and survival.
Correct answer is: A construct that contains a pre‑formed network of blood vessels
Q.150 Which of these is an example of a 'stem cell niche' component in tissue engineering?
Growth factors
Scaffold stiffness
Extracellular matrix proteins
All of the above
Explanation - The niche includes biochemical signals, mechanical cues, and matrix components.
Correct answer is: All of the above
Q.151 In tissue engineering, what is the typical role of a 'growth factor'?
To serve as a scaffold material
To guide stem cell differentiation and proliferation
To provide structural support
To degrade the scaffold
Explanation - Growth factors signal cells to divide or differentiate into specific lineages.
Correct answer is: To guide stem cell differentiation and proliferation
Q.152 Which of these is a typical method for creating a 'pre‑vascularized' scaffold?
Co‑seeded endothelial cells and fibroblasts
Using a porous structure alone
Adding only osteogenic factors
Ignoring vascularization entirely
Explanation - Co‑seeding endothelial cells helps form capillary‑like networks within the scaffold.
Correct answer is: Co‑seeded endothelial cells and fibroblasts
Q.153 What is a major challenge when implanting large engineered tissues in vivo?
Insufficient mechanical support
Limited vascularization leading to necrosis
Excessive electrical conductivity
All of the above
Explanation - Without proper blood supply, cells in the center of large constructs die.
Correct answer is: Limited vascularization leading to necrosis
Q.154 Which of the following best describes the term 'osteogenic differentiation'?
The process of forming new cartilage tissue
The transformation of stem cells into bone-forming cells
The development of nerve cells
The formation of adipose tissue
Explanation - Osteogenic differentiation is the pathway by which progenitor cells become osteoblasts.
Correct answer is: The transformation of stem cells into bone-forming cells
Q.155 What is the primary advantage of using 'bioprinted' constructs over conventional scaffold fabrication?
Higher manufacturing cost
The ability to precisely place multiple cell types and materials
Simpler sterilization
Lower resolution
Explanation - Bioprinting allows intricate spatial control of cells and biomaterials.
Correct answer is: The ability to precisely place multiple cell types and materials
Q.156 Which of these is an example of a 'natural polymer' used in tissue scaffolds?
Polyethylene glycol (PEG)
Collagen
Polylactic acid (PLA)
Polylactic-co-glycolic acid (PLGA)
Explanation - Collagen is a naturally occurring protein found in many tissues.
Correct answer is: Collagen
Q.157 Which of the following is a key metric to assess the quality of a scaffold before implantation?
Color
Mechanical strength and porosity
Size of the manufacturing batch
Price
Explanation - These properties influence how well the scaffold supports cell growth and mechanical load.
Correct answer is: Mechanical strength and porosity
Q.158 What does the term 'bioink viscosity' influence during bioprinting?
Print speed
Cell viability
Print resolution
All of the above
Explanation - Viscosity affects extrusion pressure, resolution, and cell health during printing.
Correct answer is: All of the above
Q.159 Which of the following is a common method for assessing mineral deposition in bone constructs?
Alizarin red staining
Safranin O staining
Alkaline phosphatase assay
Von Kossa staining
Explanation - Alizarin red binds to calcium deposits, indicating mineralization.
Correct answer is: Alizarin red staining
Q.160 Which of these is a typical benefit of using 'nanoporous' scaffolds?
Increased surface area for cell attachment
Reduced mechanical strength
Higher degradation rate
Increased electrical resistance
Explanation - Nanopores provide more sites for protein adsorption and cell adhesion.
Correct answer is: Increased surface area for cell attachment
Q.161 Which of the following best describes a 'bioceramic' in tissue engineering?
A metal alloy used for implants
A ceramic material that is biocompatible and promotes bone bonding
A synthetic polymer
A naturally occurring protein
Explanation - Bioceramics such as hydroxyapatite support bone integration.
Correct answer is: A ceramic material that is biocompatible and promotes bone bonding
Q.162 Which of these is a typical marker for chondrogenic differentiation?
Alkaline phosphatase
Sox9
Osteocalcin
Collagen type I
Explanation - Sox9 is a transcription factor crucial for cartilage development.
Correct answer is: Sox9
Q.163 In tissue engineering, what is the role of 'osteopontin'?
It serves as a growth factor for cartilage
It is a bone matrix protein involved in mineralization
It inhibits bone formation
It is an electrical conductor
Explanation - Osteopontin facilitates bone remodeling and cell adhesion to the mineral matrix.
Correct answer is: It is a bone matrix protein involved in mineralization