Q.1 Which growth factor is primarily involved in the healing of bone fractures?
Vascular endothelial growth factor (VEGF)
Transforming growth factor-beta (TGF-β)
Bone morphogenetic protein (BMP)
Fibroblast growth factor (FGF)
Explanation - BMPs are a group of growth factors known to stimulate bone and cartilage formation, making them essential for fracture healing.
Correct answer is: Bone morphogenetic protein (BMP)
Q.2 Which signaling pathway is activated when a growth factor binds to a receptor tyrosine kinase?
JAK/STAT pathway
MAPK/ERK pathway
Wnt/β-catenin pathway
Notch pathway
Explanation - Receptor tyrosine kinases typically activate the MAPK/ERK cascade, leading to cell proliferation and differentiation.
Correct answer is: MAPK/ERK pathway
Q.3 Which molecule acts as a primary inhibitor of angiogenesis in wound healing?
Basic fibroblast growth factor (bFGF)
Endostatin
Platelet-derived growth factor (PDGF)
Insulin-like growth factor (IGF)
Explanation - Endostatin is a natural inhibitor of angiogenesis, preventing excessive blood vessel growth during tissue repair.
Correct answer is: Endostatin
Q.4 Which growth factor is most closely associated with promoting cell proliferation in the skin?
Epidermal growth factor (EGF)
Transforming growth factor-alpha (TGF-α)
Neurotrophin
Cytokine
Explanation - EGF stimulates keratinocyte proliferation, playing a key role in skin regeneration and wound healing.
Correct answer is: Epidermal growth factor (EGF)
Q.5 Which receptor is typically found on cells that respond to vascular endothelial growth factor (VEGF)?
VEGFR-1 (Flt-1)
EGFR
Insulin receptor
TGF-β receptor
Explanation - VEGFR-1 is one of the main receptors for VEGF, mediating angiogenesis and vascular permeability.
Correct answer is: VEGFR-1 (Flt-1)
Q.6 Which signaling pathway is most closely linked to the regulation of cell fate during embryonic development?
Hedgehog pathway
NF-κB pathway
PI3K/AKT pathway
Apoptosis pathway
Explanation - The Hedgehog pathway plays a critical role in embryonic patterning and cell differentiation.
Correct answer is: Hedgehog pathway
Q.7 Which growth factor is secreted by osteoblasts to promote bone remodeling?
Osteopontin
BMP-2
Fibroblast growth factor
TNF-alpha
Explanation - BMP-2, secreted by osteoblasts, encourages bone matrix synthesis and mineralization.
Correct answer is: BMP-2
Q.8 Which of the following best describes the role of fibroblast growth factors (FGFs) in wound healing?
They inhibit inflammation.
They stimulate angiogenesis.
They promote apoptosis of cells.
They block collagen production.
Explanation - FGFs are key drivers of new blood vessel formation, essential for supplying nutrients to healing tissues.
Correct answer is: They stimulate angiogenesis.
Q.9 The Wnt/β-catenin pathway primarily affects which cellular process in tissue regeneration?
Cell apoptosis
Cell migration
Cell proliferation
Cell differentiation
Explanation - Wnt/β-catenin signaling promotes proliferation and differentiation of progenitor cells during regeneration.
Correct answer is: Cell proliferation
Q.10 Which cytokine is known to recruit immune cells to the site of tissue injury?
Interleukin-4 (IL-4)
Interleukin-8 (IL-8)
Tumor necrosis factor-alpha (TNF-α)
Interferon-gamma (IFN-γ)
Explanation - IL-8 is a chemokine that attracts neutrophils to sites of inflammation and injury.
Correct answer is: Interleukin-8 (IL-8)
Q.11 Which of the following is NOT a characteristic of a growth factor?
Small protein molecule
Requires receptor binding
Large lipid molecule
Acts on specific cell types
Explanation - Growth factors are typically small proteins or peptides, not large lipids.
Correct answer is: Large lipid molecule
Q.12 Which receptor family is involved in the signaling of many growth factors including PDGF and EGF?
G protein-coupled receptors (GPCRs)
Ion channel receptors
Receptor tyrosine kinases (RTKs)
Nicotinic acetylcholine receptors
Explanation - RTKs are the primary receptor class for growth factors like PDGF, EGF, and many others.
Correct answer is: Receptor tyrosine kinases (RTKs)
Q.13 Which growth factor is known to promote the proliferation of satellite cells during muscle repair?
Insulin-like growth factor 1 (IGF-1)
Platelet-derived growth factor (PDGF)
Vascular endothelial growth factor (VEGF)
Basic fibroblast growth factor (bFGF)
Explanation - IGF-1 stimulates satellite cell activation and proliferation, aiding muscle regeneration.
Correct answer is: Insulin-like growth factor 1 (IGF-1)
Q.14 Which pathway is typically activated by binding of TGF-β to its receptors?
Smad signaling cascade
MAPK/ERK pathway
JAK/STAT pathway
PI3K/AKT pathway
Explanation - TGF-β activates Smad proteins that regulate transcription of genes involved in cell growth and differentiation.
Correct answer is: Smad signaling cascade
Q.15 Which of the following best describes the function of the Notch signaling pathway?
Induces cell migration
Triggers apoptosis in all cell types
Controls cell differentiation decisions
Regulates circadian rhythm
Explanation - Notch signaling is critical for cell fate determination during development and tissue regeneration.
Correct answer is: Controls cell differentiation decisions
Q.16 Which growth factor is crucial for the recruitment of osteoprogenitor cells to bone injury sites?
Bone morphogenetic protein-2 (BMP-2)
Transforming growth factor-alpha (TGF-α)
Fibroblast growth factor-2 (FGF-2)
Insulin-like growth factor-2 (IGF-2)
Explanation - BMP-2 attracts osteoprogenitor cells and promotes their differentiation into bone-forming osteoblasts.
Correct answer is: Bone morphogenetic protein-2 (BMP-2)
Q.17 Which molecule is a key downstream effector in the PI3K/AKT signaling pathway?
Phosphoinositide 3-kinase (PI3K)
Phosphatase and tensin homolog (PTEN)
mammalian target of rapamycin (mTOR)
Ras
Explanation - mTOR is a critical downstream target that regulates cell growth and proliferation in the PI3K/AKT pathway.
Correct answer is: mammalian target of rapamycin (mTOR)
Q.18 Which growth factor is known for its potent neurotrophic effects on neuronal survival?
Brain-derived neurotrophic factor (BDNF)
Platelet-derived growth factor (PDGF)
Vascular endothelial growth factor (VEGF)
Fibroblast growth factor (FGF)
Explanation - BDNF supports neuron growth, survival, and synaptic plasticity, making it crucial for neural regeneration.
Correct answer is: Brain-derived neurotrophic factor (BDNF)
Q.19 Which signaling pathway is most commonly associated with the regulation of stem cell quiescence?
Hedgehog pathway
Wnt/β-catenin pathway
JAK/STAT pathway
TGF-β/Smad pathway
Explanation - TGF-β signaling maintains stem cell quiescence by inhibiting proliferation and differentiation signals.
Correct answer is: TGF-β/Smad pathway
Q.20 What is the primary function of matrix metalloproteinases (MMPs) during tissue regeneration?
Promote angiogenesis
Degrade extracellular matrix
Inhibit inflammation
Stimulate cell division
Explanation - MMPs remodel the extracellular matrix, allowing cell migration and tissue remodeling.
Correct answer is: Degrade extracellular matrix
Q.21 Which growth factor is most often used clinically to enhance wound healing in diabetic foot ulcers?
Epidermal growth factor (EGF)
Basic fibroblast growth factor (bFGF)
Platelet-derived growth factor (PDGF)
Insulin-like growth factor-1 (IGF-1)
Explanation - PDGF is approved for treating chronic wounds, including diabetic ulcers, due to its ability to recruit cells essential for healing.
Correct answer is: Platelet-derived growth factor (PDGF)
Q.22 Which of the following is a downstream target of the Ras/MAPK pathway?
Cyclin-dependent kinase inhibitors
FOXO transcription factors
Elk-1 transcription factor
NF-κB
Explanation - Elk-1 is phosphorylated by MAPK, leading to immediate early gene expression that drives proliferation.
Correct answer is: Elk-1 transcription factor
Q.23 Which receptor type is primarily responsible for detecting the presence of insulin-like growth factor (IGF) in cells?
Tyrosine kinase receptor
G protein-coupled receptor
Ion channel receptor
Nuclear receptor
Explanation - IGF signals through a receptor tyrosine kinase that triggers downstream PI3K/AKT and MAPK pathways.
Correct answer is: Tyrosine kinase receptor
Q.24 What is the role of VEGF in the context of tissue engineering scaffolds?
It acts as a scaffold material
It inhibits scaffold degradation
It promotes blood vessel formation
It reduces cell adhesion
Explanation - VEGF is incorporated into scaffolds to stimulate angiogenesis, improving tissue integration and survival.
Correct answer is: It promotes blood vessel formation
Q.25 Which pathway is directly involved in the regulation of apoptosis during tissue repair?
JAK/STAT pathway
PI3K/AKT pathway
NF-κB pathway
Wnt/β-catenin pathway
Explanation - NF-κB can either promote survival or apoptosis depending on the cellular context, balancing cell death during healing.
Correct answer is: NF-κB pathway
Q.26 Which cytokine is known to be a key regulator of macrophage activation during wound healing?
IL-10
IL-12
IL-1β
IL-4
Explanation - IL-12 drives Th1 responses and activates macrophages to a pro-inflammatory phenotype necessary for early wound healing.
Correct answer is: IL-12
Q.27 In the context of regenerative medicine, what is the main advantage of using stem cells derived from bone marrow?
They are easier to harvest
They have higher differentiation potential for bone repair
They do not require growth factors
They cause less immune rejection
Explanation - Bone marrow-derived mesenchymal stem cells can differentiate into osteoblasts, aiding bone regeneration.
Correct answer is: They have higher differentiation potential for bone repair
Q.28 Which growth factor is most commonly associated with the 'angiogenic switch' in cancer?
VEGF
EGF
TGF-β
PDGF
Explanation - VEGF is overexpressed in tumors, triggering new blood vessel formation to supply nutrients for cancer growth.
Correct answer is: VEGF
Q.29 Which signaling molecule is released by activated platelets that stimulates fibroblast proliferation?
Platelet-derived growth factor (PDGF)
Serotonin
Histamine
Thromboxane A2
Explanation - PDGF from platelets acts as a mitogen for fibroblasts, accelerating wound healing.
Correct answer is: Platelet-derived growth factor (PDGF)
Q.30 Which of the following best describes the role of the Hippo signaling pathway in tissue regeneration?
It promotes cell death to reduce cell number
It inhibits cell proliferation
It controls organ size by regulating cell proliferation and apoptosis
It exclusively controls stem cell migration
Explanation - The Hippo pathway limits organ growth by restricting proliferation and encouraging apoptosis when necessary.
Correct answer is: It controls organ size by regulating cell proliferation and apoptosis
Q.31 Which factor is crucial for the differentiation of mesenchymal stem cells into adipocytes?
Peroxisome proliferator-activated receptor gamma (PPARγ)
Runx2
Oct4
Sox2
Explanation - PPARγ is the master regulator driving adipogenic differentiation of MSCs.
Correct answer is: Peroxisome proliferator-activated receptor gamma (PPARγ)
Q.32 Which of the following is NOT typically a function of growth factors during tissue regeneration?
Stimulating cell proliferation
Recruiting immune cells
Encouraging apoptosis of damaged cells
Inhibiting protein synthesis
Explanation - Growth factors usually promote protein synthesis to support new tissue formation, not inhibit it.
Correct answer is: Inhibiting protein synthesis
Q.33 Which protein complex is essential for the transcriptional activation of TGF-β target genes?
SMAD1/5/8
SMAD2/3
SMAD4/6
SMAD7/9
Explanation - SMAD2/3 bind to receptors and partner with SMAD4 to regulate TGF-β-responsive genes.
Correct answer is: SMAD2/3
Q.34 Which of the following is a direct consequence of excessive TGF-β signaling in scar formation?
Increased angiogenesis
Reduced fibroblast activity
Enhanced collagen deposition
Decreased extracellular matrix production
Explanation - TGF-β drives fibroblast differentiation into myofibroblasts, leading to excess collagen and fibrosis.
Correct answer is: Enhanced collagen deposition
Q.35 Which growth factor is known for its ability to stimulate endothelial cell migration?
Platelet-derived growth factor (PDGF)
Basic fibroblast growth factor (bFGF)
Epidermal growth factor (EGF)
Vascular endothelial growth factor (VEGF)
Explanation - VEGF is a potent chemotactic agent for endothelial cells, promoting migration during angiogenesis.
Correct answer is: Vascular endothelial growth factor (VEGF)
Q.36 Which signaling cascade is activated by the binding of fibroblast growth factor to its receptor?
Raf-MEK-ERK
PI3K-AKT
JAK-STAT
Both Raf-MEK-ERK and PI3K-AKT
Explanation - FGFR activation stimulates both MAPK/ERK and PI3K/AKT pathways, leading to proliferation and survival.
Correct answer is: Both Raf-MEK-ERK and PI3K-AKT
Q.37 Which of these growth factors is most implicated in the repair of cardiac muscle after myocardial infarction?
Basic fibroblast growth factor (bFGF)
Transforming growth factor-beta (TGF-β)
Neuregulin-1
Platelet-derived growth factor (PDGF)
Explanation - Neuregulin-1 promotes cardiomyocyte survival and regeneration, improving post-infarction outcomes.
Correct answer is: Neuregulin-1
Q.38 Which signaling pathway is primarily responsible for the transcriptional activation of genes involved in cell cycle progression?
MAPK/ERK pathway
JNK pathway
p38 MAPK pathway
ER stress pathway
Explanation - The ERK branch of MAPK directly stimulates transcription of cyclin genes for cell cycle entry.
Correct answer is: MAPK/ERK pathway
Q.39 Which growth factor is secreted by endothelial cells and acts in an autocrine manner to promote angiogenesis?
Angiopoietin-1
VEGF
PDGF
IGF-1
Explanation - Endothelial cells produce VEGF, which stimulates their own proliferation and new vessel formation.
Correct answer is: VEGF
Q.40 Which receptor is typically upregulated during the inflammatory phase of wound healing?
EGFR
VEGFR-2
TGF-β receptor
PDGFR-α
Explanation - TGF-β signaling is enhanced during inflammation, regulating fibroblast activation and collagen deposition.
Correct answer is: TGF-β receptor
Q.41 What is the primary role of the extracellular matrix (ECM) during tissue regeneration?
To serve as a scaffold for cell migration and differentiation
To inhibit cell proliferation
To act as a source of oxygen
To reduce inflammation
Explanation - ECM provides structural support and biochemical cues for cells during regeneration.
Correct answer is: To serve as a scaffold for cell migration and differentiation
Q.42 Which of the following is a direct inhibitor of the PI3K/AKT pathway?
PTEN
AKT
mTOR
Rictor
Explanation - PTEN dephosphorylates PIP3, counteracting PI3K activity and reducing AKT activation.
Correct answer is: PTEN
Q.43 Which growth factor has been shown to improve tendon repair by stimulating tenocyte proliferation?
Epidermal growth factor (EGF)
Platelet-derived growth factor (PDGF)
Transforming growth factor-beta (TGF-β)
Neurotrophin-3
Explanation - PDGF promotes tenocyte migration and proliferation, enhancing tendon healing.
Correct answer is: Platelet-derived growth factor (PDGF)
Q.44 Which of the following pathways is commonly dysregulated in chronic inflammatory diseases affecting tissue repair?
Wnt/β-catenin
NF-κB
Hedgehog
JAK/STAT
Explanation - NF-κB activation leads to prolonged inflammation, impairing normal tissue regeneration.
Correct answer is: NF-κB
Q.45 Which molecule is released by fibroblasts during the remodeling phase to degrade excess collagen?
Collagenase
Matrix metalloproteinase-9 (MMP-9)
TGF-β
VEGF
Explanation - MMP-9 breaks down collagen fibers, allowing proper tissue remodeling and scar maturation.
Correct answer is: Matrix metalloproteinase-9 (MMP-9)
Q.46 Which of the following is a key target gene induced by the Wnt/β-catenin signaling pathway during bone regeneration?
RUNX2
HOXA9
GATA3
SIRT1
Explanation - RUNX2 is essential for osteoblast differentiation and is upregulated by Wnt signaling.
Correct answer is: RUNX2
Q.47 Which growth factor is often used to enhance the differentiation of induced pluripotent stem cells (iPSCs) into neurons?
Fibroblast growth factor-2 (FGF-2)
Transforming growth factor-beta (TGF-β)
Bone morphogenetic protein-4 (BMP-4)
Vascular endothelial growth factor (VEGF)
Explanation - FGF-2 maintains iPSC pluripotency and promotes their neural lineage commitment.
Correct answer is: Fibroblast growth factor-2 (FGF-2)
Q.48 Which cytokine is essential for the differentiation of Th17 cells during inflammatory responses?
IL-23
IL-2
IL-4
IL-10
Explanation - IL-23 promotes Th17 differentiation, which can influence tissue inflammation and repair.
Correct answer is: IL-23
Q.49 Which of the following is an example of a growth factor that signals through a G protein-coupled receptor (GPCR)?
Fibroblast growth factor
Epidermal growth factor
Serotonin
Bone morphogenetic protein
Explanation - Serotonin is a neurotransmitter that signals via GPCRs, not a traditional growth factor.
Correct answer is: Serotonin
Q.50 Which pathway is activated by the binding of insulin-like growth factor (IGF) and is important for metabolic regulation?
PI3K/AKT
MAPK/ERK
JAK/STAT
Hedgehog
Explanation - IGF activates the PI3K/AKT pathway, influencing glucose uptake and cell survival.
Correct answer is: PI3K/AKT
Q.51 Which of the following best describes the role of the Notch signaling pathway in skin homeostasis?
Promotes keratinocyte proliferation
Regulates hair follicle stem cell activation
Induces apoptosis in melanocytes
Inhibits collagen synthesis
Explanation - Notch signaling controls the activation of hair follicle stem cells during skin renewal.
Correct answer is: Regulates hair follicle stem cell activation
Q.52 Which molecule is a downstream mediator of TGF-β that promotes fibrosis by stimulating myofibroblast differentiation?
Smad2
Smad7
SMAD4
SMAD9
Explanation - Smad2 transduces TGF-β signals that lead to myofibroblast activation and fibrosis.
Correct answer is: Smad2
Q.53 Which growth factor is known to support the survival of pancreatic β-cells during regeneration?
Glial cell line-derived neurotrophic factor (GDNF)
Insulin-like growth factor-1 (IGF-1)
Epidermal growth factor (EGF)
Vascular endothelial growth factor (VEGF)
Explanation - IGF-1 promotes β-cell proliferation and survival, aiding pancreatic regeneration.
Correct answer is: Insulin-like growth factor-1 (IGF-1)
Q.54 Which of the following best describes the role of matrix stiffness in stem cell differentiation?
High stiffness promotes neuronal differentiation
Low stiffness promotes osteogenic differentiation
Medium stiffness promotes adipogenic differentiation
High stiffness promotes osteogenic differentiation
Explanation - Stem cells sense substrate stiffness; stiffer matrices favor bone-like lineage differentiation.
Correct answer is: High stiffness promotes osteogenic differentiation
Q.55 Which signaling pathway is directly activated by the binding of hepatocyte growth factor (HGF) to its receptor c-Met?
JAK/STAT
MAPK/ERK
PI3K/AKT
All of the above
Explanation - HGF/c-Met activation stimulates multiple downstream pathways, including JAK/STAT, MAPK, and PI3K/AKT.
Correct answer is: All of the above
Q.56 Which factor is considered a key regulator of the transition from the inflammatory to the proliferative phase of wound healing?
IL-4
TNF-alpha
IL-6
IL-10
Explanation - IL-10 is anti-inflammatory, helping shift the wound environment toward tissue proliferation and repair.
Correct answer is: IL-10
Q.57 Which of the following is NOT a typical source of growth factors in a tissue engineering construct?
Embedded microspheres
Genetically modified cells
Direct injection of protein
Synthetic polymer chains
Explanation - Synthetic polymers lack biological signaling capacity; they serve as structural scaffolds, not as growth factor sources.
Correct answer is: Synthetic polymer chains
Q.58 Which molecule is a direct inhibitor of the canonical Wnt/β-catenin pathway?
Dickkopf-1 (DKK1)
Sclerostin
β-catenin
Frizzled receptor
Explanation - DKK1 binds LRP5/6, preventing Wnt ligand-mediated activation of the β-catenin pathway.
Correct answer is: Dickkopf-1 (DKK1)
Q.59 Which cytokine is involved in the recruitment of fibroblasts to a wound site?
IL-8
IL-2
IL-17
IL-12
Explanation - IL-8 is a chemokine that attracts fibroblasts and other cells essential for wound repair.
Correct answer is: IL-8
Q.60 Which of the following is a major mediator of angiogenesis in the context of tumor biology?
Angiopoietin-2
VEGF
PDGF
IGF-1
Explanation - VEGF is the principal factor promoting new blood vessel formation in tumors.
Correct answer is: VEGF
Q.61 Which growth factor is known to promote the proliferation of myoblasts during skeletal muscle regeneration?
IGF-1
TGF-β
EGF
VEGF
Explanation - IGF-1 stimulates myoblast proliferation and differentiation, aiding muscle repair.
Correct answer is: IGF-1
Q.62 What is the main role of the extracellular signal-regulated kinase (ERK) within the MAPK pathway during regeneration?
Initiate apoptosis
Promote cell migration
Regulate gene transcription for proliferation
Suppress immune responses
Explanation - ERK translocates to the nucleus to activate transcription factors driving cell cycle genes.
Correct answer is: Regulate gene transcription for proliferation
Q.63 Which of the following best describes the function of fibroblast growth factor receptor 2 (FGFR2) mutations in human disease?
Lead to increased bone growth
Cause a decrease in collagen synthesis
Result in a form of craniosynostosis
Inhibit angiogenesis
Explanation - FGFR2 mutations cause premature fusion of skull sutures, leading to craniosynostosis.
Correct answer is: Result in a form of craniosynostosis
Q.64 Which signaling molecule is a key regulator of the epithelial-mesenchymal transition (EMT) during wound healing?
TGF-β
VEGF
IGF-1
IL-10
Explanation - TGF-β induces EMT, allowing epithelial cells to become migratory fibroblast-like cells.
Correct answer is: TGF-β
Q.65 Which protein acts as a coreceptor for VEGF to enhance angiogenic signaling?
Neuropilin-1
TGF-β receptor
FGFR1
PDGFRβ
Explanation - Neuropilin-1 binds VEGF and potentiates its signaling via VEGFR2.
Correct answer is: Neuropilin-1
Q.66 Which growth factor is primarily involved in the differentiation of neural progenitor cells into oligodendrocytes?
Neuregulin-1
Platelet-derived growth factor (PDGF)
Fibroblast growth factor (FGF)
Bone morphogenetic protein (BMP)
Explanation - PDGF-BB is critical for oligodendrocyte precursor cell proliferation and differentiation.
Correct answer is: Platelet-derived growth factor (PDGF)
Q.67 What is the role of the PI3K/AKT pathway in the context of cell survival during tissue regeneration?
Promotes apoptosis
Stimulates autophagy
Inhibits mTOR
Enhances anti-apoptotic signaling
Explanation - PI3K/AKT activates survival pathways that prevent programmed cell death during repair.
Correct answer is: Enhances anti-apoptotic signaling
Q.68 Which of the following molecules is a key regulator of the epithelial wound closure process?
Epidermal growth factor (EGF)
Insulin-like growth factor (IGF)
Transforming growth factor-beta (TGF-β)
Vascular endothelial growth factor (VEGF)
Explanation - EGF stimulates keratinocyte migration and proliferation to close the epidermal wound.
Correct answer is: Epidermal growth factor (EGF)
Q.69 Which pathway is known to be involved in the regulation of fibroblast-to-myofibroblast transition during scar formation?
TGF-β/Smad
JAK/STAT
Wnt/β-catenin
Notch
Explanation - TGF-β signaling via Smad proteins drives fibroblasts to become contractile myofibroblasts.
Correct answer is: TGF-β/Smad
Q.70 Which growth factor is most closely associated with the induction of osteoclast differentiation?
RANKL
VEGF
PDGF
EGF
Explanation - RANKL binds RANK on osteoclast precursors, promoting their maturation and bone resorption.
Correct answer is: RANKL
Q.71 Which cytokine is known to induce the production of M2 macrophages, facilitating tissue remodeling?
IL-4
IL-6
IL-1β
TNF-α
Explanation - IL-4 polarizes macrophages towards the anti-inflammatory M2 phenotype, supporting repair.
Correct answer is: IL-4
Q.72 What is the main function of the extracellular matrix protein fibronectin during wound healing?
Serve as a scaffold for cell adhesion
Inhibit collagen deposition
Promote inflammation
Inhibit angiogenesis
Explanation - Fibronectin provides binding sites for cells, facilitating migration and scaffold formation.
Correct answer is: Serve as a scaffold for cell adhesion
Q.73 Which of the following signaling pathways is directly activated by the binding of TGF-α to its receptor?
Ras-MAPK
PI3K-AKT
Both Ras-MAPK and PI3K-AKT
JAK-STAT
Explanation - TGF-α binding activates EGFR, which triggers both MAPK and PI3K/AKT pathways.
Correct answer is: Both Ras-MAPK and PI3K-AKT
Q.74 Which growth factor is primarily involved in the regeneration of cartilage tissue?
Transforming growth factor-beta (TGF-β)
Vascular endothelial growth factor (VEGF)
Insulin-like growth factor-1 (IGF-1)
Platelet-derived growth factor (PDGF)
Explanation - TGF-β stimulates chondrocyte proliferation and matrix synthesis for cartilage repair.
Correct answer is: Transforming growth factor-beta (TGF-β)
Q.75 Which of the following is a direct downstream effector of the Hedgehog signaling pathway?
Gli1
Smad2
β-catenin
STAT3
Explanation - Gli1 is a transcription factor activated by Hedgehog signaling, driving gene expression.
Correct answer is: Gli1
Q.76 Which of the following growth factors is used clinically to stimulate angiogenesis in ischemic tissues?
Basic fibroblast growth factor (bFGF)
Neurotrophin
Cytokine
Matrix metalloproteinase
Explanation - bFGF promotes new vessel growth, improving blood supply to ischemic tissues.
Correct answer is: Basic fibroblast growth factor (bFGF)
Q.77 Which pathway is primarily involved in regulating the balance between stem cell renewal and differentiation?
Notch
Hedgehog
Wnt/β-catenin
All of the above
Explanation - All three pathways contribute to controlling stem cell fate decisions during tissue regeneration.
Correct answer is: All of the above
Q.78 Which growth factor is most commonly used to promote hair follicle regeneration in alopecia treatments?
Platelet-derived growth factor (PDGF)
Basic fibroblast growth factor (bFGF)
Insulin-like growth factor-1 (IGF-1)
Bone morphogenetic protein (BMP)
Explanation - bFGF stimulates dermal papilla cells, encouraging hair follicle growth.
Correct answer is: Basic fibroblast growth factor (bFGF)
Q.79 Which molecule is a negative regulator of the PI3K/AKT pathway in bone marrow mesenchymal stem cells?
PTEN
Raptor
Rictor
mTORC1
Explanation - PTEN dephosphorylates PIP3, counteracting PI3K activity and limiting AKT activation.
Correct answer is: PTEN
Q.80 Which growth factor is essential for the development of the heart during embryogenesis?
Neuregulin-1
Epidermal growth factor (EGF)
Bone morphogenetic protein (BMP)
Vascular endothelial growth factor (VEGF)
Explanation - Neuregulin-1 signaling is critical for cardiac morphogenesis and maturation.
Correct answer is: Neuregulin-1
Q.81 Which of the following is a key regulator of the transition from quiescent to active fibroblasts in the wound healing process?
Transforming growth factor-beta (TGF-β)
Insulin
Glucagon
Serotonin
Explanation - TGF-β stimulates fibroblasts to proliferate and produce extracellular matrix during healing.
Correct answer is: Transforming growth factor-beta (TGF-β)
Q.82 Which of the following signaling molecules is known to play a critical role in hair follicle stem cell activation?
Wnt/β-catenin
JAK/STAT
PI3K/AKT
MAPK/ERK
Explanation - Wnt signaling triggers the activation and proliferation of hair follicle stem cells.
Correct answer is: Wnt/β-catenin
Q.83 What is the main function of fibroblast growth factor receptor 1 (FGFR1) in epidermal wound healing?
Promotes keratinocyte migration
Inhibits angiogenesis
Induces apoptosis of fibroblasts
Releases cytokines
Explanation - FGFR1 activation enhances keratinocyte motility, aiding re-epithelialization of wounds.
Correct answer is: Promotes keratinocyte migration
Q.84 Which cytokine is responsible for the recruitment of fibrocytes to a site of injury?
IL-8
IL-6
IL-10
IL-13
Explanation - IL-6 attracts fibrocytes, which contribute to extracellular matrix deposition during repair.
Correct answer is: IL-6
Q.85 Which growth factor is essential for the differentiation of mesenchymal stem cells into endothelial cells?
VEGF
PDGF
FGF
TGF-β
Explanation - VEGF drives the differentiation and proliferation of endothelial lineage cells.
Correct answer is: VEGF
Q.86 Which of the following is a direct downstream target of the JAK/STAT pathway in the context of tissue regeneration?
Cyclin D1
Smad2
β-catenin
NF-κB
Explanation - JAK/STAT activation leads to transcription of cyclin D1, promoting cell cycle progression.
Correct answer is: Cyclin D1
Q.87 Which of the following is NOT a recognized growth factor involved in bone remodeling?
Bone morphogenetic protein (BMP)
Osteoprotegerin (OPG)
Transforming growth factor-beta (TGF-β)
Platelet-derived growth factor (PDGF)
Explanation - OPG is a decoy receptor that inhibits RANKL; it is not a growth factor promoting bone growth.
Correct answer is: Osteoprotegerin (OPG)
Q.88 Which signaling pathway is most closely linked to the regulation of cellular metabolism during tissue regeneration?
PI3K/AKT/mTOR
MAPK/ERK
JAK/STAT
Wnt/β-catenin
Explanation - This pathway coordinates nutrient sensing and anabolic metabolism essential for cell growth.
Correct answer is: PI3K/AKT/mTOR
Q.89 Which growth factor is commonly used to promote neuronal regeneration in spinal cord injury models?
Brain-derived neurotrophic factor (BDNF)
Platelet-derived growth factor (PDGF)
Vascular endothelial growth factor (VEGF)
TGF-β
Explanation - BDNF supports neuron survival and axonal growth, aiding spinal cord repair.
Correct answer is: Brain-derived neurotrophic factor (BDNF)
Q.90 Which of the following best describes the role of integrins in tissue regeneration?
Signal to the nucleus directly
Serve as extracellular matrix proteins
Mediate cell-ECM adhesion and signal transduction
Act as growth factor receptors
Explanation - Integrins bind ECM proteins, influencing cell migration, proliferation, and survival.
Correct answer is: Mediate cell-ECM adhesion and signal transduction
Q.91 Which growth factor is essential for the differentiation of mesenchymal stem cells into chondrocytes?
Bone morphogenetic protein-2 (BMP-2)
Transforming growth factor-beta (TGF-β)
Epidermal growth factor (EGF)
Neurotrophin-3
Explanation - TGF-β promotes chondrogenic differentiation, essential for cartilage regeneration.
Correct answer is: Transforming growth factor-beta (TGF-β)
Q.92 Which signaling pathway is typically activated by the binding of insulin-like growth factor to its receptor?
PI3K/AKT
MAPK/ERK
JAK/STAT
Both PI3K/AKT and MAPK/ERK
Explanation - IGF-IR signaling triggers both the PI3K/AKT survival pathway and the MAPK/ERK proliferation pathway.
Correct answer is: Both PI3K/AKT and MAPK/ERK
Q.93 Which of the following growth factors is a direct inhibitor of angiogenesis?
Endostatin
Basic fibroblast growth factor (bFGF)
Vascular endothelial growth factor (VEGF)
Platelet-derived growth factor (PDGF)
Explanation - Endostatin suppresses new blood vessel formation, limiting tumor angiogenesis.
Correct answer is: Endostatin
Q.94 Which of the following best describes the primary function of the extracellular matrix in tissue repair?
Supply nutrients to cells
Serve as a scaffold for cell migration
Generate electrical signals
Regulate hormone levels
Explanation - The ECM provides structural support and biochemical cues guiding cell movement during repair.
Correct answer is: Serve as a scaffold for cell migration
Q.95 Which growth factor is often used in combination with mesenchymal stem cells to enhance bone regeneration in clinical settings?
Bone morphogenetic protein-2 (BMP-2)
Insulin-like growth factor-1 (IGF-1)
Vascular endothelial growth factor (VEGF)
Platelet-derived growth factor (PDGF)
Explanation - BMP-2 synergizes with MSCs to promote osteogenic differentiation and bone formation.
Correct answer is: Bone morphogenetic protein-2 (BMP-2)
Q.96 Which of the following is a key mediator of fibroblast activation during the proliferative phase of wound healing?
Transforming growth factor-beta (TGF-β)
Interferon-gamma (IFN-γ)
Interleukin-10 (IL-10)
Tumor necrosis factor-alpha (TNF-α)
Explanation - TGF-β signals fibroblasts to produce extracellular matrix proteins during proliferation.
Correct answer is: Transforming growth factor-beta (TGF-β)
Q.97 Which growth factor is responsible for promoting the maturation of hair follicles during the anagen phase?
Platelet-derived growth factor (PDGF)
Epidermal growth factor (EGF)
Basic fibroblast growth factor (bFGF)
Bone morphogenetic protein (BMP)
Explanation - bFGF stimulates hair follicle stem cells, initiating the growth (anagen) phase.
Correct answer is: Basic fibroblast growth factor (bFGF)
Q.98 Which of the following is a direct downstream target of the Hedgehog signaling pathway?
Gli1
β-catenin
Smad2
STAT3
Explanation - Gli1 is a transcription factor activated by Hedgehog signaling and regulates target genes.
Correct answer is: Gli1
Q.99 Which growth factor is most commonly used to promote the regeneration of cardiac tissue after myocardial infarction in animal studies?
Neuregulin-1
Basic fibroblast growth factor (bFGF)
Platelet-derived growth factor (PDGF)
Bone morphogenetic protein (BMP)
Explanation - Neuregulin-1 improves cardiomyocyte survival and functional recovery post-infarction.
Correct answer is: Neuregulin-1
Q.100 Which molecule is a key inhibitor of the PI3K/AKT pathway during skeletal muscle regeneration?
PTEN
mTORC1
Rictor
S6K1
Explanation - PTEN dephosphorylates PIP3, thereby inhibiting PI3K/AKT signaling and reducing muscle cell proliferation.
Correct answer is: PTEN