TRB PG Assistant - Mutation – types, causes, detection, significance Online Test (MCQ Quiz)

1. What is a mutation?

A) A permanent change in the DNA sequence of an organism. B) A temporary alteration in gene expression. C) The process of cell division. D) The transfer of genetic material between bacteria.

2. Which type of mutation involves a change in a single nucleotide base?

A) Chromosomal mutation B) Point mutation C) Polyploidy D) Aneuploidy

3. A substitution mutation where the new codon codes for the same amino acid is called a:

A) Missense mutation B) Nonsense mutation C) Silent mutation D) Frameshift mutation

4. What is a missense mutation?

A) A mutation that changes a codon to a stop codon. B) A mutation that results in a different amino acid being incorporated into the protein. C) A mutation that does not alter the amino acid sequence. D) A mutation involving the insertion or deletion of nucleotides.

5. A mutation that introduces a premature stop codon, leading to a truncated protein, is known as a:

A) Missense mutation B) Silent mutation C) Nonsense mutation D) Frameshift mutation

6. Which type of mutation occurs when one or more nucleotide bases are added to a DNA sequence?

A) Deletion B) Substitution C) Insertion D) Duplication

7. A mutation caused by the removal of one or more nucleotide bases from a DNA sequence is called a:

A) Insertion B) Substitution C) Deletion D) Translocation

8. What is a frameshift mutation?

A) A substitution that changes a codon to another codon for a different amino acid. B) A mutation that adds or deletes nucleotides, shifting the reading frame of codons. C) A mutation that results in a premature stop codon. D) A mutation that does not change the amino acid sequence.

9. Which of the following is an example of a chromosomal mutation?

A) Point mutation B) Silent mutation C) Deletion of a gene segment D) Substitution of a base pair

10. A chromosomal mutation involving the detachment of a segment from one chromosome and its attachment to a non-homologous chromosome is called:

A) Inversion B) Translocation C) Deletion D) Duplication

11. What is an inversion mutation?

A) A segment of a chromosome breaks off and reattaches in the reverse orientation. B) A segment of a chromosome is lost. C) A segment of a chromosome is duplicated. D) A segment from one chromosome attaches to another.

12. A chromosomal mutation where a segment of a chromosome is repeated is known as:

A) Deletion B) Inversion C) Duplication D) Translocation

13. What is aneuploidy?

A) The gain or loss of entire sets of chromosomes. B) The gain or loss of one or more chromosomes, but not entire sets. C) The fusion of chromosomes. D) The splitting of chromosomes.

14. The condition of having an abnormal number of chromosomes in a cell, such as having an extra chromosome 21 (Down syndrome), is an example of:

A) Polyploidy B) Aneuploidy C) Euploidy D) Haploidy

15. What is polyploidy?

A) Having a single set of chromosomes. B) Having the normal diploid number of chromosomes. C) Having more than two complete sets of chromosomes. D) Having an abnormal number of individual chromosomes.

16. Which of the following is a known cause of spontaneous mutations?

A) Exposure to high levels of UV radiation B) Errors during DNA replication C) Ingestion of certain chemicals D) X-ray irradiation

17. What are mutagens?

A) Enzymes that repair DNA. B) Agents that can cause mutations. C) Proteins involved in DNA replication. D) Types of RNA molecules.

18. Which of these is a physical mutagen?

A) Nitrous acid B) Ethidium bromide C) Ionizing radiation D) Base analogs

19. Which of these is a chemical mutagen?

A) Ultraviolet (UV) radiation B) X-rays C) Alkylating agents D) Gamma rays

20. Ultraviolet (UV) radiation primarily causes mutations by:

A) Causing base substitutions. B) Forming thymine dimers. C) Inducing frameshift mutations. D) Leading to chromosomal breaks.

21. Ionizing radiation, like X-rays, can cause mutations by:

A) Intercalating into DNA. B) Alkylating DNA bases. C) Breaking the DNA backbone. D) Mimicking normal bases.

22. Base analogs are mutagens that:

A) Insert themselves between DNA bases. B) Chemically modify existing bases. C) Can be mistakenly incorporated into DNA during replication due to structural similarity to normal bases. D) Cause cross-linking of DNA strands.

23. Intercalating agents are mutagens that:

A) Add chemical groups to bases. B) Mimic DNA bases. C) Insert themselves into the DNA double helix, distorting its structure and causing insertions or deletions. D) Break the phosphodiester bonds.

24. Which of the following is a method used for detecting mutations?

A) DNA sequencing B) Gel electrophoresis C) PCR (Polymerase Chain Reaction) D) All of the above

25. The Ames test is commonly used to detect:

A) Chromosomal abnormalities. B) Mutations in bacteria. C) Protein folding defects. D) Gene expression levels.

26. What is the primary principle behind using DNA sequencing to detect mutations?

A) Separating DNA fragments by size. B) Determining the order of nucleotide bases in a DNA molecule. C) Amplifying specific DNA segments. D) Visualizing DNA under a microscope.

27. Gel electrophoresis can help detect mutations by:

A) Identifying the exact nucleotide sequence. B) Revealing changes in DNA fragment size due to insertions or deletions. C) Detecting the presence of specific proteins. D) Measuring the rate of DNA replication.

28. Which technique allows for the amplification of specific DNA regions to screen for mutations?

A) Southern blotting B) Northern blotting C) Western blotting D) PCR (Polymerase Chain Reaction)

29. Somatic mutations occur in:

A) Germ cells (sperm and egg cells). B) Body cells (non-reproductive cells). C) Gametes. D) Zygotes.

30. Germline mutations occur in:

A) Skin cells. B) Liver cells. C) Cells that give rise to gametes. D) Neurons.

31. Which type of mutation can be passed on to offspring?

A) Somatic mutation B) Germline mutation C) Induced mutation D) Spontaneous mutation

32. Mutations that occur in somatic cells are:

A) Heritable. B) Not heritable. C) Always lethal. D) Always beneficial.

33. What is the significance of mutations in evolution?

A) They reduce genetic variation. B) They are the source of new genetic variation. C) They only cause harmful effects. D) They lead to the extinction of species.

34. A mutation that increases an organism's fitness in its environment is called a(n):

A) Deleterious mutation B) Neutral mutation C) Beneficial mutation D) Lethal mutation

35. Most mutations are considered to be:

A) Beneficial B) Deleterious C) Neutral D) Lethal

36. What is a neutral mutation?

A) A mutation that is always harmful. B) A mutation that is always beneficial. C) A mutation that has no significant effect on an organism's fitness. D) A mutation that causes death.

37. Mutations can lead to the development of:

A) Genetic stability. B) New traits and adaptations. C) Reduced biodiversity. D) Immunity to all diseases.

38. Which genetic disorder is caused by a point mutation in the hemoglobin gene?

A) Cystic fibrosis B) Huntington's disease C) Sickle cell anemia D) Down syndrome

39. Down syndrome is a result of which type of mutation?

A) Point mutation B) Frameshift mutation C) Aneuploidy (Trisomy 21) D) Chromosomal deletion

40. Cancer is often associated with the accumulation of:

A) Germline mutations. B) Somatic mutations in critical genes (oncogenes and tumor suppressor genes). C) Beneficial mutations. D) Neutral mutations.

41. The ability of viruses to rapidly evolve new strains is largely due to:

A) Slow mutation rates. B) High mutation rates and short generation times. C) Lack of genetic material. D) Undergoing only beneficial mutations.

42. Which enzyme is primarily responsible for proofreading and correcting errors during DNA replication, thus minimizing spontaneous mutations?

A) DNA ligase B) RNA polymerase C) DNA polymerase D) Helicase

43. A mutation that renders a gene non-functional is often described as a:

A) Gain-of-function mutation B) Loss-of-function mutation C) Neutral mutation D) Dominant mutation

44. Gain-of-function mutations typically result in:

A) A protein with reduced activity. B) A protein with a novel or enhanced activity. C) A complete loss of protein function. D) No change in protein function.

45. The genetic code's degeneracy (multiple codons for one amino acid) provides a buffer against the effects of which type of mutation?

A) Nonsense mutation B) Frameshift mutation C) Missense mutation D) Insertion mutation

46. What is the term for mutations that occur spontaneously without exposure to external mutagens?

A) Induced mutations B) Somatic mutations C) Spontaneous mutations D) Germline mutations

47. Which of the following is a type of point mutation?

A) Translocation B) Duplication C) Inversion D) Substitution

48. The significance of mutations lies in their role as the ultimate source of:

A) Genetic stability B) Genetic variation C) Cellular differentiation D) Homeostasis

49. Which of the following is NOT a type of chromosomal mutation?

A) Deletion B) Translocation C) Point mutation D) Inversion

Mutation – types, causes, detection, significance - Online Test

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