Life Sciences Multiple Choice Questions on “Cytogenetics”.
1. What is Cytogenetics?
A. Genetic disorders
B. Phenotypic variation
C. Study of chromosomes
D. Qualitative traits
Answer: C
Clarification: Cytogenetics is the study of the function, structure, and abnormalities of the chromosomes. It is the combination of cytology and genetics.
2. Human consists of 46 chromosomes or 23 pairs of chromosomes.
A. True
B. False
Answer: A
Clarification: Tijo and Levan (1956) of Sweden had discovered that human cells consist of 23 pairs of chromosomes or 46 chromosomes.
3. The diagram which shows the arrangement of metaphasic chromosomes according to their position of centromere is called________
A. Histogram
B. Karyogram
C. Dendrogram
D. Ideogram
Answer: D
Clarification: Ideogram is a photograph or a diagram of all Metaphasic chromosome arranged in homologous pair as per decreasing order of their centromeres.
4. Which of the following designation has given to human female chromosomes?
A. XX
B. XY
C. XO
D. ZZ
Answer: A
Clarification: Humans consist of two similar chromosomes(XX) for female sex chromosome and two dissimilar chromosome (XY) in male.
5. Which of the following is NOT the dye-based chromosome banding?
A. Giemsa
B. Reverse
C. Centromere
D. Metacentric
Answer: D
Clarification: Chromosome banding is a differential staining procedure which separates the chromosome along the longitudinal axis. The most common banding procedure is dye-staining, which is of four types, i.e. giemsa, centromere, reverse, and quinacrine.
6. Name the term which defines the presence or absence of extra copies of a few chromosomes.
A. Extranuclear inheritance
B. Aneuploidy
C. Euploidy
D. Diploid
Answer: B
Clarification: Ploidy is defined as the numerical changes in chromosome numbers. It is basically of two types, euploidy involve a complete set of a chromosome, while aneuploidy refers to the presence and absence of a few copies of chromosomes but not a whole set.
7. Alteration in which of the following chromosome shows Down syndrome?
A. Sex chromosome
B. 18
C. 21
D. 13
Answer: C
Clarification: Down syndrome is an autosomal aneuploidy disorder in human beings. The presence of an extra chromosome in 21st number of chromosome makes total chromosome number 47.
8. Mark the INCORRECT statement about Edward’s syndrome.
A. Trisomy of chromosome 18
B. Mental and motor retardation
C. Dwarfism
D. Clenched hand and overlapping fingers
Answer: C
Clarification: Edward’s syndrome is the second most common autosomal aneuploidy, which involves trisomy in chromosome 18.
9. Which of the following is CORRECT for Turner syndrome?
A. Slanting eyes
B. Autosomal aneuploidy
C. Suppressive
D. Retarded sexual development
Answer: D
Clarification: Turner syndrome is sex chromosomal aneuploidy, which is characterized by the absence of an X chromosome making total chromosome number 45. These are females with retarder sexual development.
10. Which of the following chromosomal aberration shows pseudodominance?
A. Deletion
B. Duplication
C. Inversions
D. Translocation
Answer: A
Clarification: Deletion in heterozygous allele cause a recessive allele to become expressed phenotypically which causes pseudodominance.
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