With reference to 'Somatic stem cells', consider the following statements:
1. They are found in developed tissues like bone marrow and skin.
2. Somatic stem cells are multipotent rather than pluripotent.
3. They are harvested exclusively from the brains of human embryos.
Which of the statements given above are correct?
- 2 and 3
- 1 and 2
- 1, 2, 3
- 1 and 3
Explanation: Statement 3 is incorrect. Somatic stem cells (adult stem cells) are found in fully developed humans, from infancy to old age, in many different organs; they are not harvested from embryos.
Consider the following statements about Stem Cell 'Differentiation':
1. It is the process where a stem cell becomes a more specialized cell.
2. Proliferation refers to the expansion of the cell population by division.
3. Differentiation and proliferation always happen at exactly the same rate.
Which of the statements given above are correct?
- 1 and 3
- 1 and 2
- 1, 2, 3
- 2 and 3
Explanation: Statement 3 is incorrect. Differentiation and proliferation are distinct processes. A cell can proliferate (divide) without differentiating, and once it fully differentiates, its ability to proliferate often decreases.
With reference to Stem Cell Aging (Senescence), consider the following statements:
1. Aging leads to a decline in the regenerative capacity of resident stem cells.
2. Stem cells are biologically immortal and never experience telomere shortening.
3. Chronic inflammation in the niche contributes to the aging of stem cell pools.
Which of the statements given above are correct?
- 2 and 3
- 1 and 3
- 1, 2, 3
- 1 and 2
Explanation: Statement 2 is incorrect. Stem cells do age, experience telomere shortening, and accumulate DNA damage, which is why the body's healing slows down with age.
Consider the following statements concerning Somatic Cell Nuclear Transfer (SCNT):
1. It is used to create patient-specific embryonic stem cells (therapeutic cloning).
2. SCNT involves inserting an adult cell nucleus into an enucleated egg.
3. SCNT is the primary method used for human reproductive cloning in India.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1, 2, 3
- 1 and 3
Explanation: Statement 3 is incorrect. Human reproductive cloning is strictly prohibited in India. SCNT is only permitted for research and therapeutic purposes (therapeutic cloning).
Regarding the difference between Differentiation and Proliferation, consider the following:
1. Differentiation is the acquisition of specialized cell characteristics.
2. Proliferation refers to the process where a stem cell dies immediately.
3. Stem cells must balance self-renewal and differentiation to maintain tissue.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 2 and 3
- 1 and 3
Explanation: Statement 2 is incorrect. Proliferation is the expansion of a cell population by division; it is the opposite of cell death.
Regarding Neural Stem Cells (NSCs), consider the following statements:
1. NSCs can differentiate into neurons, astrocytes, and oligodendrocytes.
2. Adult neurogenesis occurs in the subventricular zone and hippocampus.
3. Human neural stem cells can be harvested via a non-invasive blood test.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1 and 3
- 1, 2, 3
Explanation: Statement 3 is incorrect. Neural stem cells are located deep in the brain and spinal cord. Harvesting them is highly invasive and requires neurosurgery, not a blood test.
With reference to Stem Cell Exosomes, consider the following statements:
1. They are extracellular vesicles that carry proteins and RNA from stem cells.
2. Exosome therapy is considered a 'cell-free' regenerative medicine approach.
3. Exosomes are large multicellular structures visible to the naked eye.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1 and 3
- 1, 2, 3
Explanation: Statement 3 is incorrect. Exosomes are microscopic nanoparticles (vesicles) secreted by cells; they are much smaller than cells and cannot be seen without an electron microscope.
Consider the following statements about the risk of Teratoma formation:
1. Teratomas are harmless benign growths that never contain differentiated tissues.
2. Undifferentiated pluripotent stem cells carry a significant risk of forming teratomas.
3. Teratoma assays are used in laboratories to confirm the pluripotency of ESCs.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 1 and 3
- 2 and 3
Explanation: Statement 1 is incorrect. Teratomas can be complex and are a major safety concern in stem cell therapy because they contain disorganized tissues like hair, teeth, and muscle.
With reference to Limbal Stem Cells, consider the following statements:
1. They are located in the eye and regenerate the corneal epithelium.
2. Limbal Stem Cell Deficiency can be caused by chemical burns or trauma.
3. LSCD is a condition that solely affects the retina and optic nerve.
Which of the statements given above are correct?
- 1 and 3
- 2 and 3
- 1 and 2
- 1, 2, 3
Explanation: Statement 3 is incorrect. Limbal stem cell deficiency affects the cornea (the clear front surface of the eye), leading to scarring and vision loss. It does not affect the retina or optic nerve directly.
Regarding the 2026 status of Stem Cell Therapy in India, consider the following:
1. ICMR guidelines classify stem cell-based products as 'New Drugs'.
2. Clinical trials for stem cell therapy require CDSCO approval.
3. All hospitals can offer stem cell therapy for autism as a standard care.
Which of the statements given above are correct?
- 1 and 2
- 1, 2, 3
- 1 and 3
- 2 and 3
Explanation: Statement 3 is incorrect. In India, most stem cell therapies (including for autism, cerebral palsy, etc.) are considered experimental. Only hematopoietic stem cell transplantation for specific blood disorders is an 'established' standard of care.
Consider the following statements concerning Stem Cell 'Self-Renewal':
1. It is the ability to divide while maintaining an undifferentiated state.
2. Asymmetric division produces one stem cell and one progenitor cell.
3. Stem cells can only undergo a single division before dying off.
Which of the statements given above are correct?
- 1, 2, 3
- 2 and 3
- 1 and 2
- 1 and 3
Explanation: Statement 3 is incorrect. The defining feature of stem cells is their capacity for self-renewal, meaning they can divide many times to maintain the stem cell pool over the lifetime of the organism.
With reference to Mitochondrial Replacement Therapy (MRT), consider the following:
1. It prevents the transmission of mitochondrial diseases from mother to child.
2. The resulting child has DNA from the father, mother, and an egg donor.
3. MRT is a standard clinical treatment for adult-onset heart failure.
Which of the statements given above are correct?
- 1 and 3
- 1, 2, 3
- 2 and 3
- 1 and 2
Explanation: Statement 3 is incorrect. MRT is an assisted reproductive technology performed on embryos/oocytes to prevent inherited diseases. It is not used to treat adult conditions like heart failure.
Regarding adult neurogenesis in humans, consider the following statements:
1. The subgranular zone of the hippocampus produces new neurons in adults.
2. This process is linked to the formation of memories and learning.
3. Adult humans produce over ten million new brain neurons every hour.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 2 and 3
- 1 and 3
Explanation: Statement 3 is incorrect. While neurogenesis occurs, it is a slow process producing relatively few neurons; the figure of ten million per hour is medically impossible.
Regarding Epigenetic Memory in reprogrammed cells, consider the following:
1. iPSCs can retain chemical marks from their original adult cell type.
2. This memory can influence how the cell differentiates in the future.
3. Successful reprogramming requires 'resetting' the epigenetic landscape.
Which of the statements given above are correct?
- 2 and 3
- 1 and 3
- 1 and 2
- 1, 2, 3
Explanation: All statements are correct. Epigenetics controls gene expression. If an iPSC 'remembers' being a skin cell, it might not perform as well as a nerve cell.
Regarding the biological potential of human stem cells, consider the following statements:
1. Totipotent cells can differentiate into both embryonic and extra-embryonic tissues.
2. Pluripotent cells can form all specialized cells of the three germ layers.
3. Multipotent cells are restricted to forming specific cell lineages of a tissue.
Which of the statements given above are correct?
- 1 and 3
- 1 and 2
- 2 and 3
- 1, 2, 3
Explanation: All statements are correct. Totipotent cells (zygote) form everything. Pluripotent cells (ESCs/iPSCs) form the body but not the placenta. Multipotent cells (Adult SCs) are lineage-restricted.
Regarding Stem Cells and Diabetes, consider the following statements:
1. Scientists aim to create beta cells from stem cells to produce insulin.
2. This therapy could potentially cure Type 1 diabetes in the future.
3. Stem cell therapy is now the standard cure for 100% of diabetics.
Which of the statements given above are correct?
- 1 and 3
- 2 and 3
- 1 and 2
- 1, 2, 3
Explanation: Statement 3 is incorrect. While research is in advanced stages and clinical trials are promising, stem cell therapy is not yet a standard, widespread cure for diabetes.
With reference to the mechanism of Stem Cell Homing, consider the following:
1. It is a purely mechanical process that only occurs during surgery.
2. Chemical signals (chemokines) guide stem cells to the site of injury.
3. Homing allows systemically injected stem cells to find target tissues.
Which of the statements given above are correct?
- 1, 2, 3
- 2 and 3
- 1 and 2
- 1 and 3
Explanation: Statement 1 is incorrect. Homing is a biological, signal-driven process that can happen when cells are injected into the blood, not just via surgery.
With reference to the 2026 status of stem cell 'Standards of Care' in India:
1. HSCT for specific blood disorders is an established standard of care.
2. Reproductive cloning is fully permitted for research and therapy.
3. Use of stem cells for most other conditions is strictly experimental.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1, 2, 3
- 1 and 3
Explanation: Statement 2 is incorrect. Human reproductive cloning remains strictly prohibited in India and is not allowed even for research.
With reference to the Graft-versus-Tumor (GVT) effect, consider the following:
1. It is a desired outcome where donor cells attack cancer in the recipient.
2. GVT is always harmful and results in immediate patient death.
3. The effect is mainly observed in allogeneic hematopoietic transplants.
Which of the statements given above are correct?
- 2 and 3
- 1, 2, 3
- 1 and 2
- 1 and 3
Explanation: Statement 2 is incorrect. GVT is the beneficial side of a transplant where the new immune system kills the cancer. The harmful version is GVHD.
With reference to Stem Cell 'Homing', consider the following statements:
1. It is the migration of stem cells to the site of injury via blood.
2. Homing is driven by chemical signals (chemokines) from damaged tissue.
3. Stem cells can only reach injured sites if they are directly injected there.
Which of the statements given above are correct?
- 2 and 3
- 1 and 3
- 1 and 2
- 1, 2, 3
Explanation: Statement 3 is incorrect. Stem cells have a natural 'homing' ability that allows them to find injured areas even when injected intravenously, provided the appropriate chemical signals are present.
Consider the following statements regarding Limbal Stem Cells:
1. They are located at the edge of the cornea in a region called the limbus.
2. They are essential for the continuous renewal of the corneal surface.
3. Deficiency in these cells can lead to corneal blindness and scarring.
Which of the statements given above are correct?
- 1 and 2
- 1, 2, 3
- 1 and 3
- 2 and 3
Explanation: All statements are correct. These cells are vital for vision; their loss (LSCD) is a recognized clinical indication for stem cell grafting.
Consider the following statements regarding Mesenchymal Stem Cells (MSCs):
1. MSCs are pluripotent cells harvested exclusively from five-day-old human embryos.
2. They possess immunomodulatory properties that suppress excessive inflammatory responses.
3. MSCs are commonly used in research for bone and cartilage regeneration.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1 and 3
- 1, 2, 3
Explanation: Statement 1 is incorrect. MSCs are multipotent adult stem cells found in bone marrow, fat, and cord blood; they are not embryonic.
Consider the following statements regarding 'Chimeras' in research:
1. Chimeras contain cells from two or more different species.
2. Growing human organs in animals involves creating chimeric embryos.
3. Ethical guidelines in India currently allow the birth of human clones.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 1 and 3
- 2 and 3
Explanation: Statement 3 is incorrect. India, along with almost every other country, strictly prohibits human reproductive cloning (the birth of a human clone).
With reference to Somatic vs. Embryonic stem cells, consider the following statements:
1. Somatic stem cells are multipotent and found in fully developed tissues.
2. Embryonic stem cells are unipotent and can only form skin tissues.
3. ESCs are derived from the inner cell mass of the blastocyst stage.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 3
- 2 and 3
- 1 and 2
Explanation: Statement 2 is incorrect. ESCs are pluripotent, meaning they can form almost any cell type in the body, not just skin.
Regarding the use of Bio-inks in 3D Bioprinting, consider the following statements:
1. Bio-inks typically consist of living cells embedded in a hydrogel.
2. Bio-inks are made of toxic lead to ensure the print remains stable.
3. The material must be biocompatible and support cell survival/growth.
Which of the statements given above are correct?
- 1 and 3
- 1, 2, 3
- 2 and 3
- 1 and 2
Explanation: Statement 2 is incorrect. Lead is toxic and would kill the living cells. Bio-inks must be non-toxic and biocompatible.
With reference to Cancer Stem Cells (CSCs), consider the following statements:
1. CSCs are a small tumor sub-population capable of self-renewal and tumorigenesis.
2. They are often more resistant to standard chemotherapy than regular tumor cells.
3. CSCs were discovered to be the primary cause of Type 1 Diabetes.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1, 2, 3
- 1 and 3
Explanation: Statement 3 is incorrect. CSCs are related to cancer recurrence and spread. Type 1 Diabetes is an autoimmune disease involving the destruction of pancreatic beta cells.
Regarding Exosome-based therapies, consider the following statements:
1. Exosomes are large, nucleated cells derived from the patient's heart tissue.
2. They are extracellular vesicles that carry molecular signals between cells.
3. Exosome therapy is considered a 'cell-free' alternative to stem cell transplants.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 1 and 3
- 2 and 3
Explanation: Statement 1 is incorrect. Exosomes are not cells; they are tiny vesicles (nanoparticles) secreted by cells. They lack a nucleus.
Concerning the properties of Scaffolds in tissue engineering, consider the following:
1. Scaffolds must be made of radioactive uranium to stimulate growth.
2. They must provide a high degree of porosity to allow nutrient flow.
3. Most modern scaffolds are designed to be biodegradable over time.
Which of the statements given above are correct?
- 2 and 3
- 1, 2, 3
- 1 and 3
- 1 and 2
Explanation: Statement 1 is incorrect. Uranium is highly toxic and radioactive. Scaffolds must be biocompatible (safe for life).
With reference to Induced Pluripotent Stem Cells (iPSCs), consider the following statements:
1. They are derived from somatic cells using specific transcription factor cocktails.
2. iPSCs carry a high risk of immune rejection in autologous applications.
3. They allow for the creation of patient-specific disease models for research.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 1 and 3
- 2 and 3
Explanation: Statement 2 is incorrect. iPSCs are often autologous (made from the patient's own cells), which significantly reduces the risk of immune rejection compared to foreign cells.
Regarding 'Stem Cell Culture', consider the following statements:
1. Stem cells are grown in sterile dishes with specific nutrient media.
2. Feeder layers provide factors that prevent premature differentiation.
3. Culture dishes are kept in open air at 0 degrees Celsius for growth.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 2 and 3
- 1 and 3
Explanation: Statement 3 is incorrect. Stem cells must be cultured in a highly controlled environment, usually in an incubator at 37 degrees Celsius with specific levels of CO2 and oxygen.
Regarding the 'Graft-versus-Tumor' (GVT) effect, consider the following:
1. It occurs when donor immune cells attack the recipient's cancer cells.
2. GVT is a desired effect in allogeneic hematopoietic transplants.
3. GVT is the primary cause of death in 90% of transplant patients.
Which of the statements given above are correct?
- 1 and 3
- 1, 2, 3
- 1 and 2
- 2 and 3
Explanation: Statement 3 is incorrect. GVT is a positive therapeutic effect. The primary causes of mortality in transplants are Graft-versus-Host Disease (GVHD), infections, and relapse, not the GVT effect.
Regarding Hematopoietic Stem Cell Transplantation (HSCT), consider the following:
1. It is the only widely established stem cell therapy for blood-related cancers.
2. In allogeneic transplants, the donor's immune cells may attack recipient tissues.
3. Autologous transplants involve using stem cells harvested from a matched sibling.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 3
- 2 and 3
- 1 and 2
Explanation: Statement 3 is incorrect. Autologous transplants use the patient's own cells. Transplants from a sibling or donor are called allogeneic.
Regarding the 2012 Nobel Prize in Physiology or Medicine, consider the following:
1. It was awarded to Gurdon and Yamanaka for reprogramming mature cells.
2. Their work proved that the specialization of cells is reversible.
3. The prize was given for inventing a mechanical heart for transplants.
Which of the statements given above are correct?
- 1 and 3
- 1 and 2
- 2 and 3
- 1, 2, 3
Explanation: Statement 3 is incorrect. The prize was awarded for the discovery that mature, specialized cells can be reprogrammed to become immature, pluripotent stem cells (iPSCs).
Regarding Hematopoietic Stem Cell Transplantation (HSCT), consider the following:
1. It is a standard clinical treatment for leukemia and aplastic anemia.
2. Allogeneic HSCT involves using stem cells from a genetically matched donor.
3. Graft-versus-Host Disease (GVHD) is a complication of autologous transplants.
Which of the statements given above are correct?
- 1, 2, 3
- 2 and 3
- 1 and 2
- 1 and 3
Explanation: Statement 3 is incorrect. GVHD occurs in allogeneic transplants where the donor's immune cells attack the recipient's body. It does not occur in autologous transplants since the patient uses their own cells.
With reference to Organoids, consider the following statements:
1. They are 3D, miniaturized organ models grown from stem cells.
2. Organoids are used for drug testing and disease modeling in vitro.
3. Organoids are life-sized organs used for surgical heart transplants.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1, 2, 3
- 1 and 3
Explanation: Statement 3 is incorrect. Organoids are microscopic or millimeter-sized models used for research. They are not full-sized, functional organs for human transplantation.
Consider the following statements about Cartilage Repair using stem cells:
1. Articular cartilage has a very limited natural capacity for self-repair.
2. MSCs are being researched to treat localized cartilage defects in joints.
3. Stem cell therapy is now the primary cure for advanced osteoporosis.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 2 and 3
- 1 and 3
Explanation: Statement 3 is incorrect. Stem cell therapy for joints focuses on cartilage and osteoarthritis. Advanced osteoporosis is a systemic bone density issue treated with drugs.
Concerning Mesenchymal Stem Cells (MSCs), consider the following statements:
1. MSCs can differentiate into bone, cartilage, and fat cells.
2. They are found in bone marrow, adipose tissue, and umbilical cord.
3. MSCs are primarily used to treat neurodegenerative disorders like Alzheimer's.
Which of the statements given above are correct?
- 1 and 3
- 1 and 2
- 2 and 3
- 1, 2, 3
Explanation: Statement 3 is incorrect. While being researched, MSCs are currently most established in regenerative medicine for musculoskeletal issues (bone/cartilage) and immunomodulation, rather than as a standard treatment for Alzheimer's.
Consider the following statements about 'Stem Cell Plasticity':
1. It refers to the ability of adult stem cells to cross lineage boundaries.
2. Plasticity allows a blood stem cell to potentially become a nerve cell.
3. All adult stem cells are naturally pluripotent and show infinite plasticity.
Which of the statements given above are correct?
- 1 and 3
- 1, 2, 3
- 1 and 2
- 2 and 3
Explanation: Statement 3 is incorrect. Adult stem cells have limited 'plasticity' (transdifferentiation). They are mostly multipotent or unipotent; they are not naturally pluripotent like embryonic stem cells.
Consider the following statements about 'Stem Cell Banking' for pets:
1. Private facilities exist to store stem cells from dogs and cats.
2. These cells can be used for treating joint injuries in animals.
3. All domestic pets in India must be cloned by law by 2027.
Which of the statements given above are correct?
- 1 and 3
- 2 and 3
- 1 and 2
- 1, 2, 3
Explanation: Statement 3 is incorrect. There is no law requiring or even broadly permitting the cloning of domestic pets in India; pet banking is a private, voluntary service.
Concerning the regulatory framework for Stem Cell Research in India, consider the following:
1. The ICMR and DBT jointly formulated the National Guidelines for research.
2. These guidelines prohibit the commercial use of unproven stem cell therapies.
3. All clinical trials using stem cells must be registered with the CTRI.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 1 and 3
- 2 and 3
Explanation: All statements are correct. India has a strict regulatory structure to prevent exploitation, mandating adherence to national guidelines and trial registration.
Consider the following statements concerning CRISPR-modified stem cells:
1. Gene editing can correct genetic mutations in a patient's own stem cells.
2. These modified cells can be used to treat disorders like sickle cell anemia.
3. CRISPR modification in stem cells is currently banned for all human research.
Which of the statements given above are correct?
- 1 and 2
- 1, 2, 3
- 1 and 3
- 2 and 3
Explanation: Statement 3 is incorrect. While germline editing (embryos) is restricted, CRISPR research on somatic (adult) stem cells is ongoing and has clinical applications.
Regarding the use of iPSCs in pharmaceutical drug discovery, consider the following:
1. Human iPSC-derived cells provide a more accurate model than animal testing.
2. It is legally mandatory to replace all animal testing with iPSCs globally.
3. These cells are used to screen for potential cardiotoxicity in new drugs.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1, 2, 3
- 1 and 3
Explanation: Statement 2 is incorrect. While iPSCs are reducing reliance on animals, animal testing remains a regulatory requirement in most jurisdictions before human trials.
Regarding Liver regeneration and stem cell potential, consider the following:
1. The liver is the only human organ that cannot regenerate any tissue.
2. Hepatocytes can regenerate, but stem cells assist in severe damage.
3. MSCs are being investigated for treating chronic liver cirrhosis.
Which of the statements given above are correct?
- 2 and 3
- 1, 2, 3
- 1 and 2
- 1 and 3
Explanation: Statement 1 is incorrect. The liver has a remarkably high natural capacity for regeneration compared to other solid human organs.
Consider the following statements about the Stem Cell Niche:
1. It is the microenvironment that regulates stem cell self-renewal and fate.
2. The niche provides signals to keep stem cells in a quiescent state.
3. Physical contact with the extracellular matrix is unnecessary for the niche.
Which of the statements given above are correct?
- 1 and 3
- 1 and 2
- 2 and 3
- 1, 2, 3
Explanation: Statement 3 is incorrect. The stem cell niche relies heavily on physical contact with the extracellular matrix and neighboring cells to provide the mechanical and chemical signals required to maintain 'stemness'.
With reference to the Stem Cell Niche, consider the following statements:
1. It is the microenvironment that regulates stem cell self-renewal and differentiation.
2. The niche provides chemical and mechanical signals to maintain cell stemness.
3. The extracellular matrix is a vital component of the anatomical stem cell niche.
Which of the statements given above are correct?
- 1 and 3
- 1, 2, 3
- 1 and 2
- 2 and 3
Explanation: All statements are correct. The niche is the biological home of the stem cell, providing all necessary signals (chemical, physical, and matrix-based) to control its behavior.
With reference to the 'Three Germ Layers', consider the following statements:
1. Pluripotent stem cells can form ectoderm, mesoderm, and endoderm.
2. The nervous system and skin are derived from the ectoderm layer.
3. The digestive and respiratory systems are formed from the mesoderm.
Which of the statements given above are correct?
- 1 and 2
- 1, 2, 3
- 2 and 3
- 1 and 3
Explanation: Statement 3 is incorrect. The digestive and respiratory tracts are primarily derived from the endoderm. The mesoderm forms muscle, bone, blood, and the heart.
Consider the following statements about Cord Blood preservation:
1. Cord blood contains a high concentration of blood-forming stem cells.
2. It can be used as a source for hematopoietic stem cell transplants.
3. Storage can be done in either private commercial or public donation banks.
Which of the statements given above are correct?
- 1 and 3
- 1, 2, 3
- 2 and 3
- 1 and 2
Explanation: All statements are correct. Cord blood is a legitimate medical source of HSCs and can be stored in various types of facilities.
Regarding the location of Neural Stem Cells (NSCs) in humans, consider the following:
1. Adult neurogenesis occurs in the subventricular zone and hippocampus.
2. NSCs can differentiate into neurons, astrocytes, and oligodendrocytes.
3. Neural stem cells are found in the dead skin cells of the human scalp.
Which of the statements given above are correct?
- 1 and 2
- 1 and 3
- 1, 2, 3
- 2 and 3
Explanation: Statement 3 is incorrect. NSCs are located deep within the central nervous system (brain and spinal cord), not in the dead outer layer of the skin.
With reference to Embryonic Stem Cells (ESCs), consider the following statements:
1. They are derived from the inner cell mass of the blastocyst.
2. ESCs are legally categorized as 'adult stem cells' in Indian regulations.
3. Their use involves significant ethical debate due to embryo destruction.
Which of the statements given above are correct?
- 1 and 2
- 1 and 3
- 2 and 3
- 1, 2, 3
Explanation: Statement 2 is incorrect. ESCs are embryonic stem cells. Adult stem cells are those found in developed tissues like bone marrow, skin, or the brain.
Regarding the potential of stem cells in Cardiac Repair, consider the following:
1. The adult human heart has a naturally high and infinite regenerative rate.
2. Stem cell patches are being developed to repair tissue after heart attacks.
3. Stem cells can be stimulated to differentiate into functional cardiomyocytes.
Which of the statements given above are correct?
- 2 and 3
- 1 and 3
- 1 and 2
- 1, 2, 3
Explanation: Statement 1 is incorrect. The human heart has very limited natural regeneration, which is why heart attacks lead to permanent scarring and failure.
Consider the following statements concerning stem cells and Parkinson's disease:
1. The goal is to replace dopamine-producing neurons lost in the brain.
2. Pluripotent stem cells can be differentiated into dopaminergic neurons.
3. Stem cell therapy is currently a government-mandated cure for all stages.
Which of the statements given above are correct?
- 1 and 2
- 1 and 3
- 1, 2, 3
- 2 and 3
Explanation: Statement 3 is incorrect. Stem cell therapy for Parkinson's is still in clinical trials and is not a mandated or widespread standard cure.
Regarding the risk of Teratomas, consider the following statements:
1. A teratoma is a tumor containing tissues from multiple germ layers.
2. The risk of teratoma is higher when using pluripotent stem cells.
3. Teratomas are only found in patients who have never received stem cells.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 2
- 2 and 3
- 1 and 3
Explanation: Statement 3 is incorrect. Teratomas can occur naturally, but in regenerative medicine, they are a specific safety risk associated with the transplantation of undifferentiated pluripotent stem cells.
With reference to Public and Private Cord Blood Banks, consider the following:
1. Public banks store donated samples available for any matched patient.
2. Private banks are provided for free by the government to all citizens.
3. Medical associations generally favor public banks for the community.
Which of the statements given above are correct?
- 1 and 3
- 1 and 2
- 1, 2, 3
- 2 and 3
Explanation: Statement 2 is incorrect. Private banks are commercial entities that charge families substantial fees to store their specific cord blood.
Consider the following statements concerning 'Bio-inks' in 3D bioprinting:
1. Bio-inks must be biocompatible to support the survival of stem cells.
2. They often consist of hydrogels that mimic the extracellular matrix.
3. All bio-inks are made of metal alloys to provide skeletal support.
Which of the statements given above are correct?
- 1 and 3
- 2 and 3
- 1 and 2
- 1, 2, 3
Explanation: Statement 3 is incorrect. Bio-inks for tissue engineering are typically soft, biocompatible materials (like hydrogels) because they must hold living cells. Metallic alloys are used for traditional rigid implants, not for bioprinting living tissues.
Regarding Stem Cell Senescence, consider the following statements:
1. It is the permanent arrest of cell division due to aging or stress.
2. Senescent stem cells lose their regenerative potential over time.
3. Stem cells never age and maintain infinite power for 1000 years.
Which of the statements given above are correct?
- 1 and 3
- 2 and 3
- 1 and 2
- 1, 2, 3
Explanation: Statement 3 is incorrect. Stem cells age just like other cells. Their decline in function (senescence) is why our bodies heal more slowly as we get older.
Regarding 'Cord Blood Banking', consider the following statements:
1. It preserves hematopoietic stem cells from the umbilical cord and placenta.
2. Private cord blood banking is medically recommended for all healthy births.
3. Cord blood stem cells can be used to treat various blood-related cancers.
Which of the statements given above are correct?
- 1, 2, 3
- 1 and 3
- 2 and 3
- 1 and 2
Explanation: Statement 2 is incorrect. Major medical organizations generally do not recommend private banking for 'low-risk' families because the chance of a child using their own cord blood is extremely low; public donation is preferred.
Regarding the potency of stem cells, consider the following statements:
1. Totipotent cells can form both embryonic and extra-embryonic tissues.
2. Pluripotent cells can form all three germ layers but not the placenta.
3. Multipotent cells are limited to a specific lineage of cell types.
Which of the statements given above are correct?
- 1 and 2
- 1 and 3
- 1, 2, 3
- 2 and 3
Explanation: All statements are correct. Totipotent cells (like the zygote) can form a whole organism. Pluripotent cells (like ESCs) form the body but not the placenta. Multipotent cells (like blood stem cells) are restricted to their tissue family.
Consider the following statements concerning Cancer Stem Cells (CSCs):
1. They are a subpopulation of tumor cells that can self-renew.
2. CSCs are believed to be responsible for cancer recurrence and metastasis.
3. Conventional chemotherapy is 100% effective in killing all CSCs.
Which of the statements given above are correct?
- 1 and 3
- 1, 2, 3
- 1 and 2
- 2 and 3
Explanation: Statement 3 is incorrect. One of the biggest challenges in oncology is that CSCs are often resistant to standard chemotherapy and radiation, allowing the cancer to return after treatment.
With reference to Induced Pluripotent Stem Cells (iPSCs), consider the following statements:
1. They are created by reprogramming adult somatic cells using specific factors.
2. iPSCs carry a significant risk of immune rejection in autologous transplants.
3. They offer a way to study disease mechanisms in patient-specific cells.
Which of the statements given above are correct?
- 1 and 2
- 1, 2, 3
- 1 and 3
- 2 and 3
Explanation: Statement 2 is incorrect. Since iPSCs can be made from a patient's own cells (autologous), the risk of immune rejection is significantly lower compared to using foreign embryonic stem cells.
With reference to the Ethical Debate over stem cell research, consider the following:
1. The status of the blastocyst is the central point of ethical contention.
2. Informed consent is a mandatory requirement for all cell donations.
3. Some religions oppose research that involves the destruction of embryos.
Which of the statements given above are correct?
- 1 and 2
- 2 and 3
- 1, 2, 3
- 1 and 3
Explanation: All statements are correct. The debate centers on when life begins, the necessity of donor consent, and differing religious/moral perspectives on embryos.