Cytogenetics MCQs

1. Which of the following processes is responsible for the formation of genetic recombination in meiosis?
(A) Independent assortment
(B) Crossing over
(C) Cytokinesis
(D) DNA replication

2. Which of the following is a type of chromosomal aberration that results in the loss of a part of a chromosome?
(A) Duplication
(B) Inversion
(C) Deletion
(D) Translocation

3. In cytogenetics, the term “polyploidy” refers to:
(A) A condition where there is an abnormal number of chromosomes in the cell
(B) The presence of more than two complete sets of chromosomes in an organism
(C) The loss of a single chromosome from the chromosomal set
(D) The rearrangement of genes on a chromosome

4. Which of the following statements about Down syndrome is true?
(A) It is caused by a duplication of chromosome 21
(B) It results from an extra copy of chromosome 13
(C) It is caused by trisomy of chromosome 21
(D) It is caused by a translocation between chromosome 21 and chromosome 13

5. Which type of chromosomal mutation is characterized by the reversal of the orientation of a chromosome segment?
(A) Duplication
(B) Deletion
(C) Inversion
(D) Translocation

6. In human genetics, a karyotype analysis involves:
(A) Studying the sequence of DNA base pairs
(B) Counting and identifying chromosomes in a cell
(C) Analyzing the pattern of gene expression
(D) Determining the nucleotide composition of a gene

7. In cytogenetics, a “centric fusion” is best described as:
(A) The fusion of two non-homologous chromosomes resulting in a metacentric chromosome
(B) The separation of chromatids during mitosis
(C) The loss of a chromosome during cell division
(D) The fusion of two identical chromatids to form a diploid structure

8. What is the major consequence of a Robertsonian translocation?
(A) Loss of genetic material
(B) Formation of a ring chromosome
(C) Fusion of two acrocentric chromosomes
(D) Inversion of a chromosomal segment

9. Which of the following is NOT a characteristic of aneuploidy?
(A) It involves the gain or loss of individual chromosomes
(B) It can lead to conditions like Down syndrome or Turner syndrome
(C) It always results in a normal phenotype
(D) It can occur due to errors in meiosis

10. In the context of cytogenetics, “C-banding” is a technique used to:
(A) Identify specific genes on chromosomes
(B) Distinguish heterochromatin from euchromatin
(C) Visualize translocation events between chromosomes
(D) Measure the DNA content in cells

11. Which of the following chromosomal abnormalities is associated with infertility in humans?
(A) Trisomy 21
(B) Klinefelter syndrome
(C) Turner syndrome
(D) Both b and c

12. In cytogenetics, what is “gene dosage” and how can it be affected by chromosomal mutations?
(A) The number of alleles present for a particular gene
(B) The amount of genetic material in the genome
(C) The number of copies of a gene that are present, which can be altered in cases of deletions or duplications
(D) The distribution of genes across chromosomes

13. Which of the following genetic disorders is caused by a chromosomal inversion?
(A) Chronic myelogenous leukemia
(B) Down syndrome
(C) Hemophilia
(D) None of the above

14. The “Barr body” is typically found in:
(A) Males only
(B) Females only
(C) Both males and females
(D) Both males and females, but only in individuals with Turner syndrome

15. Which of the following can cause a “deletion” in a chromosome?
(A) Unequal crossing over
(B) Transposition
(C) Robertsonian translocation
(D) All of the above