TRB PG Assistant - Regeneration, aging, stem cells Online Test (MCQ Quiz)

1. What is the primary characteristic of regeneration in biology?

A) The complete loss of a body part. B) The ability to regrow lost or damaged tissues or organs. C) A form of asexual reproduction where a new organism grows from a fragment. D) The process of programmed cell death.

2. Which of the following is a classic example of an organism known for its remarkable regenerative capabilities?

A) Elephant B) Domestic Cat C) Starfish D) Human

3. In the context of regeneration, what does 'blastema' refer to?

A) A mature, differentiated cell. B) A mass of undifferentiated cells that forms at the site of injury. C) The final regenerated tissue. D) A signaling molecule that inhibits regeneration.

4. What type of regeneration involves the replacement of lost body parts with identical structures?

A) Compensatory regeneration B) Epimorphosis C) Morphallaxis D) Asexual reproduction

5. Morphallaxis, a type of regeneration, involves:

A) The formation of a blastema. B) Repatterning of existing tissues to form a new structure. C) Complete regrowth of a lost limb. D) Cell division and differentiation of stem cells.

6. Which of these is NOT a factor that typically influences regeneration?

A) Age of the organism B) Species C) Environmental conditions D) Nutritional status of the organism

7. The process of aging is also known as:

A) Senescence B) Apoptosis C) Mitosis D) Gametogenesis

8. What is a hallmark of cellular aging at the molecular level?

A) Telomere elongation B) Increased telomerase activity C) Telomere shortening D) Uncontrolled cell proliferation

9. Which theory of aging suggests that aging is due to the accumulation of damage to DNA and other molecules over time?

A) Programmed theory of aging B) Wear-and-tear theory C) Free radical theory D) Endocrine theory

10. The accumulation of senescent cells in tissues is associated with:

A) Enhanced tissue repair B) Increased organ function C) Age-related diseases and tissue dysfunction D) Accelerated regeneration

11. What is the primary role of telomeres in relation to aging?

A) They are the site of DNA replication. B) They protect the ends of chromosomes and shorten with each cell division. C) They are responsible for protein synthesis. D) They are involved in cell signaling pathways.

12. Stem cells are characterized by their ability to:

A) Undergo rapid apoptosis. B) Differentiate into specialized cell types and self-renew. C) Produce only one specific type of cell. D) Remain permanently undifferentiated.

13. Which type of stem cell is found in early-stage embryos and can differentiate into any cell type in the body?

A) Adult stem cells B) Mesenchymal stem cells C) Embryonic stem cells D) Induced pluripotent stem cells

14. Adult stem cells are also known as:

A) Totipotent stem cells B) Pluripotent stem cells C) Multipotent stem cells D) Unipotent stem cells

15. What is a key characteristic of induced pluripotent stem cells (iPSCs)?

A) They are derived from embryos. B) They are naturally occurring and found in adult tissues. C) They are reprogrammed adult cells that resemble embryonic stem cells. D) They can only differentiate into a limited range of cell types.

16. What is the main application of stem cells in regenerative medicine?

A) To induce cancer. B) To repair or replace damaged tissues and organs. C) To cause aging. D) To inhibit cell division.

17. Which of these is a potential therapeutic use of stem cells?

A) Treating genetic disorders B) Causing autoimmune diseases C) Inducing organ failure D) Preventing cell differentiation

18. The process by which stem cells become specialized cells is called:

A) Cellular senescence B) Apoptosis C) Cell differentiation D) Telomere shortening

19. Which factor is crucial for controlling the self-renewal and differentiation of stem cells?

A) Mitochondrial dysfunction B) Growth factors and signaling pathways C) Accumulation of somatic mutations D) Telomere attrition

20. What is a major ethical concern associated with embryonic stem cell research?

A) Their inability to differentiate. B) The destruction of embryos. C) Their potential to cause aging. D) Their limited self-renewal capacity.

21. Which organism is often studied for its ability to regenerate its entire body from small fragments?

A) Drosophila melanogaster B) Caenorhabditis elegans C) Hydra D) Mus musculus

22. Compensatory regeneration is characterized by:

A) The regrowth of a lost part to its original size and form. B) The enlargement of remaining tissue to compensate for lost tissue. C) Repatterning of existing tissues. D) Asexual reproduction.

23. Which of the following is a known consequence of cellular senescence?

A) Increased cell proliferation B) Release of pro-inflammatory factors (SASP) C) Enhanced tissue regeneration D) Unrestricted stem cell activity

24. The 'Hayflick limit' refers to:

A) The maximum lifespan of an organism. B) The number of times a normal human cell population will divide before cell division stops. C) The rate of telomere shortening. D) The threshold for apoptosis.

25. Which of these is a type of adult stem cell found in bone marrow that can differentiate into various blood cell types?

A) Neural stem cells B) Hematopoietic stem cells C) Epidermal stem cells D) Intestinal stem cells

26. What is the term for the process where cells undergo programmed cell death, which is distinct from aging but can be influenced by it?

A) Mitosis B) Senescence C) Apoptosis D) Regeneration

27. The study of aging is called:

A) Embryology B) Immunology C) Gerontology D) Histology

28. Which of the following is a challenge in using stem cells for therapy?

A) Controlling their differentiation into the desired cell type. B) Preventing their self-renewal. C) Ensuring they undergo senescence. D) Making them divide too slowly.

29. In the context of aging, oxidative stress is primarily caused by:

A) Excessive telomere elongation. B) The accumulation of reactive oxygen species (ROS). C) Increased telomerase activity. D) Rapid cell differentiation.

30. Which type of stem cell is totipotent?

A) Somatic cell B) Zygote and early blastomeres C) Blastocyst inner cell mass cells D) Adult stem cell

31. What is the primary challenge in achieving successful regeneration in mammals compared to simpler organisms?

A) Lack of undifferentiated cells. B) Presence of a robust immune system that may reject foreign tissues. C) Formation of scar tissue that inhibits regrowth. D) All of the above.

32. A key difference between epimorphosis and morphallaxis in regeneration is that epimorphosis:

A) Involves extensive cell dedifferentiation. B) Relies on the reorganization of existing tissue. C) Typically occurs in simpler organisms. D) Requires the formation of a blastema and growth of new tissue.

33. Which of the following is a characteristic feature of cellular senescence?

A) Unlimited proliferative potential B) Resistance to apoptotic stimuli C) Shortened telomeres D) Increased DNA repair efficiency

34. What is the role of the 'stem cell niche'?

A) To induce differentiation. B) To provide a microenvironment that supports stem cell self-renewal and regulates their differentiation. C) To trigger apoptosis. D) To facilitate scar formation.

35. Which of these conditions is being investigated for stem cell therapy?

A) Common cold B) Parkinson's disease C) Seasonal allergies D) Minor cuts and bruises

36. The programmed aging of an organism is often linked to:

A) Uncontrolled cell division. B) Genetic factors and cellular damage accumulation. C) The absence of telomerase. D) Enhanced regenerative capacity.

37. What is the term for the process where a cell loses its specialized characteristics and becomes more primitive?

A) Differentiation B) Senescence C) Dedifferentiation D) Apoptosis

38. Which theory proposes that aging is a result of accumulated errors in gene expression and protein synthesis?

A) Wear-and-tear theory B) Programmed theory C) Error catastrophe theory D) Free radical theory

39. What type of stem cells are found in the inner cell mass of the blastocyst?

A) Somatic stem cells B) Embryonic stem cells C) Induced pluripotent stem cells D) Germline stem cells

40. Regeneration in organisms like planarians is often described as:

A) Compensatory growth B) Epimorphosis C) Morphallaxis D) Neoteny

41. Which of the following is a potential risk associated with stem cell transplantation?

A) Immune rejection of the transplanted cells B) Complete loss of cell function C) Rapid aging of the recipient D) Inhibition of normal cell growth

42. The accumulation of non-functional proteins is a hallmark of:

A) Early development B) Regeneration C) Cellular aging D) Rapid cell division

43. What is the primary function of stem cells in a developing embryo?

A) To form scar tissue B) To generate all the specialized cell types of the organism C) To induce aging D) To prevent cell division

44. Which term describes the process of aging at the organismal level?

A) Apoptosis B) Senescence C) Mitosis D) Regeneration

45. The ability of some salamanders to regenerate complex structures like limbs and even parts of the brain is an example of:

A) Asexual reproduction B) Compensatory regeneration C) Epimorphosis D) Morphallaxis

46. What are the two fundamental properties of stem cells?

A) Senescence and apoptosis B) Self-renewal and differentiation C) Dedifferentiation and metaplasia D) Mitosis and meiosis

47. Which of the following is a cellular mechanism that contributes to aging?

A) Telomere maintenance B) Increased telomerase activity C) Mitochondrial dysfunction D) Enhanced DNA repair

48. What is the primary goal of research into regeneration?

A) To understand how to induce aging. B) To develop therapies for tissue repair and organ replacement. C) To prevent cell differentiation. D) To study asexual reproduction.

49. Induced pluripotent stem cells (iPSCs) offer a potential alternative to embryonic stem cells because:

A) They are easier to isolate. B) They avoid the ethical concerns associated with embryo use. C) They can only differentiate into a single cell type. D) They naturally occur in adult tissues.

50. The gradual decline in the function of cells, tissues, and organs over time is characteristic of:

A) Rapid regeneration B) Developmental biology C) Aging D) Apoptosis

Regeneration, aging, stem cells - Online Test

Test Results