Human genetics – pedigree analysis, karyotypes, genetic disorders - Question Bank

1. 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
2. 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
3. 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.
4. 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
5. Which genetic disorder causes progressive deterioration of muscle tissue?
A) Hemophilia
B) Duchenne muscular dystrophy
C) Cystic fibrosis
D) Sickle cell anemia
6. 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
7. 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
8. 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
9. What is the term for genetic disorders that affect the blood's ability to clot?
A) Anemias
B) Thalassemias
C) Coagulopathies
D) Leukemias
10. 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
11. 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
12. 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
13. Patau syndrome is caused by trisomy of which chromosome?
A) Chromosome 13
B) Chromosome 18
C) Chromosome 21
D) Chromosome Y
14. Edwards syndrome is associated with trisomy of which chromosome?
A) Chromosome 13
B) Chromosome 18
C) Chromosome 21
D) Chromosome X
15. 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
16. 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
17. 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.
18. 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
19. 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.
20. A vertical line descending from a mating line in a pedigree chart leads to:
A) Parents
B) Siblings
C) Offspring
D) Grandparents
21. In pedigree analysis, a horizontal line connecting a male and female symbol indicates:
A) Siblings
B) Offspring
C) Marriage or mating
D) Consanguinity
22. 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
23. 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
24. 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
25. 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.
26. A change in a single base pair of DNA is called a:
A) Chromosomal aberration
B) Gene mutation
C) Polyploidy
D) Aneuploidy
27. What is the term for a change in the DNA sequence of a gene?
A) Karyotype
B) Pedigree
C) Mutation
D) Allele
28. 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
29. 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
30. Hemophilia is a classic example of which type of genetic disorder?
A) Autosomal dominant
B) Autosomal recessive
C) X-linked recessive
D) Chromosomal deletion
31. 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
32. 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
33. Cystic fibrosis is inherited in what manner?
A) Autosomal dominant
B) Autosomal recessive
C) X-linked recessive
D) Y-linked
34. 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
35. 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
36. Down syndrome is caused by trisomy of which chromosome?
A) Chromosome 13
B) Chromosome 18
C) Chromosome 21
D) Chromosome X
37. What is the chromosomal abnormality associated with Turner syndrome?
A) 47, XXY
B) 45, X
C) 47, +21
D) 47, +18
38. A karyotype showing 47, XXY indicates which condition?
A) Down syndrome
B) Turner syndrome
C) Klinefelter syndrome
D) Edwards syndrome
39. 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
40. 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.
41. 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
42. Human somatic cells typically have how many chromosomes?
A) 23
B) 44
C) 46
D) 47
43. 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.
44. 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
45. 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.
46. 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
47. 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
48. 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.
49. In a pedigree chart, what symbol typically represents a male individual?
A) A circle
B) A square
C) A diamond
D) A triangle
50. 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.