TRB PG Assistant - Human genetics – pedigree analysis, karyotypes, genetic disorders Online Test (MCQ Quiz)

1. What is the primary purpose of pedigree analysis in human genetics?

A) To determine the exact physical traits of an individual. B) To trace the inheritance of genetic traits or disorders through generations. C) To identify new mutations in a population. D) To measure the rate of gene flow between different groups.

2. In a pedigree chart, what symbol typically represents a male individual?

A) A circle B) A square C) A diamond D) A triangle

3. What does a shaded symbol in a pedigree chart indicate?

A) The individual is deceased. B) The individual is unaffected by the trait being studied. C) The individual is affected by the trait being studied. D) The individual is a carrier of the trait.

4. Which mode of inheritance is characterized by the trait appearing in every generation and affecting males and females equally?

A) Autosomal recessive B) Autosomal dominant C) X-linked recessive D) X-linked dominant

5. If a genetic disorder appears in a family only when an individual inherits two copies of the mutated gene, what is the likely mode of inheritance?

A) Autosomal dominant B) Autosomal recessive C) X-linked dominant D) Y-linked

6. Which of the following is a hallmark of X-linked recessive inheritance?

A) Affected fathers pass the trait to all their sons. B) Affected mothers pass the trait to all their daughters. C) More males are typically affected than females. D) The trait appears in every generation.

7. In X-linked dominant inheritance, an affected father will pass the trait to:

A) All of his sons B) None of his sons C) All of his daughters D) None of his daughters

8. What is a karyotype?

A) A diagram showing the arrangement of genes on a chromosome. B) A photograph of an individual's complete set of chromosomes, arranged in homologous pairs. C) A genetic test to determine the probability of inheriting a disorder. D) A sequence of DNA that codes for a specific protein.

9. Human somatic cells typically have how many chromosomes?

A) 23 B) 44 C) 46 D) 47

10. What does the '2n' notation represent in genetics?

A) Haploid number of chromosomes B) Diploid number of chromosomes C) Gamete chromosome number D) Mutated chromosome number

11. What is an autosome?

A) A sex chromosome (X or Y). B) Any chromosome that is not a sex chromosome. C) A chromosome that carries genes for mitochondrial DNA. D) A chromosome involved in meiosis.

12. Which pair of chromosomes determines the biological sex of an individual in humans?

A) Autosomes 1-22 B) The sex chromosomes (X and Y) C) Chromosome 21 D) Chromosome 18

13. A karyotype showing 47, XXY indicates which condition?

A) Down syndrome B) Turner syndrome C) Klinefelter syndrome D) Edwards syndrome

14. What is the chromosomal abnormality associated with Turner syndrome?

A) 47, XXY B) 45, X C) 47, +21 D) 47, +18

15. Down syndrome is caused by trisomy of which chromosome?

A) Chromosome 13 B) Chromosome 18 C) Chromosome 21 D) Chromosome X

16. Which of the following is a common characteristic of individuals with Down syndrome?

A) Short stature and webbed neck B) Intellectual disability and distinctive facial features C) Sterility in males and underdeveloped sexual characteristics D) Absence of one X chromosome

17. Sickle cell anemia is an example of which type of genetic disorder?

A) Chromosomal abnormality B) Autosomal recessive disorder C) Autosomal dominant disorder D) X-linked disorder

18. Cystic fibrosis is inherited in what manner?

A) Autosomal dominant B) Autosomal recessive C) X-linked recessive D) Y-linked

19. Which genetic disorder is characterized by a deficiency in the enzyme phenylalanine hydroxylase?

A) Tay-Sachs disease B) Huntington's disease C) Phenylketonuria (PKU) D) Hemophilia

20. Huntington's disease is an example of which mode of inheritance?

A) Autosomal recessive B) Autosomal dominant C) X-linked recessive D) X-linked dominant

21. Hemophilia is a classic example of which type of genetic disorder?

A) Autosomal dominant B) Autosomal recessive C) X-linked recessive D) Chromosomal deletion

22. What is the primary defect in individuals with Tay-Sachs disease?

A) Defective hemoglobin production B) Accumulation of gangliosides in nerve cells C) Lack of clotting factors D) Impaired chloride ion transport

23. Which genetic disorder results from a mutation in the dystrophin gene, leading to progressive muscle degeneration?

A) Muscular dystrophy (Duchenne type) B) Cystic fibrosis C) Sickle cell anemia D) Marfan syndrome

24. What is the term for a change in the DNA sequence of a gene?

A) Karyotype B) Pedigree C) Mutation D) Allele

25. A change in a single base pair of DNA is called a:

A) Chromosomal aberration B) Gene mutation C) Polyploidy D) Aneuploidy

26. What is a Barr body?

A) An extra Y chromosome in males. B) An inactivated X chromosome in females. C) A chromosome abnormality in Down syndrome. D) A carrier state for X-linked disorders.

27. Which condition is characterized by the absence of an X chromosome in females?

A) Klinefelter syndrome B) Down syndrome C) Turner syndrome D) Triple X syndrome

28. A person with a karyotype of 47, XXX is said to have:

A) Turner syndrome B) Klinefelter syndrome C) Triple X syndrome D) Edwards syndrome

29. The genetic disorder caused by a mutation in the CFTR gene leads to:

A) Reduced blood clotting B) Progressive muscle weakness C) Thick, sticky mucus buildup D) Neurodegenerative disease

30. In pedigree analysis, a horizontal line connecting a male and female symbol indicates:

A) Siblings B) Offspring C) Marriage or mating D) Consanguinity

31. A vertical line descending from a mating line in a pedigree chart leads to:

A) Parents B) Siblings C) Offspring D) Grandparents

32. What does the Roman numeral 'I' typically represent in a pedigree chart?

A) The first generation of offspring. B) The parental generation. C) The second generation. D) The affected individuals.

33. A diamond shape in a pedigree chart usually represents:

A) An affected male B) An affected female C) An individual whose sex is unknown or not relevant D) A carrier female

34. If a trait is X-linked recessive, and an unaffected mother has an affected son, what must be true about the father?

A) The father must be affected. B) The father must be a carrier. C) The father must be unaffected. D) The father's status is irrelevant.

35. A karyotype is prepared from which type of human cells?

A) Red blood cells B) Gametes (sperm or egg) C) Somatic cells (e.g., white blood cells) D) Nerve cells

36. What term describes the condition where an individual has a mixture of cells with different chromosome numbers?

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

37. Edwards syndrome is associated with trisomy of which chromosome?

A) Chromosome 13 B) Chromosome 18 C) Chromosome 21 D) Chromosome X

38. Patau syndrome is caused by trisomy of which chromosome?

A) Chromosome 13 B) Chromosome 18 C) Chromosome 21 D) Chromosome Y

39. What is the primary characteristic of Marfan syndrome?

A) Defective blood clotting B) Abnormal connective tissue development C) Excessive iron absorption D) Reduced red blood cell production

40. Which of the following is NOT a typical feature of Klinefelter syndrome (47, XXY)?

A) Reduced fertility in males B) Development of breast tissue (gynecomastia) C) Presence of two X chromosomes and one Y chromosome D) Short stature

41. A genetic disorder that primarily affects the nervous system and is characterized by the breakdown of nerve cells is:

A) Cystic fibrosis B) Sickle cell anemia C) Tay-Sachs disease D) Hemophilia

42. What is the term for genetic disorders that affect the blood's ability to clot?

A) Anemias B) Thalassemias C) Coagulopathies D) Leukemias

43. Which of the following is a consequence of a mutation in the HBB gene, leading to abnormal hemoglobin?

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

44. What is the term for the complete set of chromosomes in a cell, arranged in order of size and type?

A) Genome B) Karyotype C) Genotype D) Phenotype

45. The inheritance pattern where a trait is passed from an affected mother to all her children (both sons and daughters) is characteristic of:

A) Autosomal dominant B) Autosomal recessive C) X-linked dominant D) Mitochondrial inheritance

46. Which genetic disorder causes progressive deterioration of muscle tissue?

A) Hemophilia B) Duchenne muscular dystrophy C) Cystic fibrosis D) Sickle cell anemia

47. A female with Turner syndrome (45, X) typically presents with:

A) Normal fertility and development B) Underdeveloped sexual characteristics and sterility C) Increased risk of breast cancer D) Development of male secondary sex characteristics

48. What does the 'haploid' number of chromosomes (n) represent?

A) The total number of chromosomes in a somatic cell. B) The number of chromosomes in a gamete (sperm or egg). C) The number of pairs of homologous chromosomes. D) The number of sex chromosomes.

49. Which of the following is a common method for obtaining cells for karyotype analysis?

A) Urine sample B) Saliva sample C) Blood sample D) Hair follicle sample

50. In pedigree analysis, a double line connecting a male and female symbol indicates:

A) Siblings B) Offspring C) Consanguineous mating (mating between relatives) D) Adoption

Human genetics – pedigree analysis, karyotypes, genetic disorders - Online Test

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