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Cytogenetics — MCQs Biology

1. Cytogenetics is the branch of biology that deals with the study of:

(A) Cell metabolism


(B) Tissue organization


(C) Chromosomes and their behavior


(D) Molecular enzymes




2. The term chromosome was coined by:

(A) Waldeyer


(B) Fleming


(C) Sutton


(D) Mendel




3. Chromosomes are best visible during:

(A) Interphase


(B) Prophase


(C) Metaphase


(D) Telophase




4. The constricted region of a chromosome is called:

(A) Chromatid


(B) Telomere


(C) Centromere


(D) Kinetochore




5. The ends of chromosomes are known as:

(A) Telomeres


(B) Chromomeres


(C) Centromeres


(D) Origins




6. A chromosome with the centromere in the middle is called:

(A) Acrocentric


(B) Metacentric


(C) Telocentric


(D) Submetacentric




7. Chromosomes having centromere near one end are:

(A) Metacentric


(B) Submetacentric


(C) Acrocentric


(D) Holocentric




8. A chromosome without a centromere is known as:

(A) Dicentric


(B) Polycentric


(C) Acentric


(D) Telocentric




9. The number of chromosomes in somatic human cells is:

(A) 23


(B) 44


(C) 46


(D) 48




10. Haploid chromosome number in humans is:

(A) 23


(B) 22


(C) 44


(D) 46




11. The complete set of chromosomes of an organism is called:

(A) Genome


(B) Nucleotype


(C) Idiogram


(D) Karyotype




12. Diagrammatic representation of chromosomes arranged in order is called:

(A) Idiogram


(B) Nucleolus


(C) Genome


(D) Chromatid




13. Chromosomal study using staining techniques is known as:

(A) Karyotyping


(B) Autoradiography


(C) Gene mapping


(D) PCR




14. G-banding technique is mainly used to:

(A) Count ribosomes


(B) Identify chromosome regions


(C) Detect proteins


(D) Observe RNA




15. The nucleolar organizer region (NOR) is associated with:

(A) mRNA synthesis


(B) rRNA synthesis


(C) tRNA synthesis


(D) DNA replication




16. Secondary constrictions are found at:

(A) Telomeres


(B) Centromeres


(C) NOR regions


(D) Chromatids




17. Polyploidy refers to the presence of:

(A) Extra genes


(B) More than two sets of chromosomes


(C) Extra chromosomes


(D) Mutated DNA




18. Aneuploidy involves:

(A) Change in gene sequence


(B) Duplication of genome


(C) Change in chromosome sets


(D) Loss or gain of one or few chromosomes




19. Down syndrome is caused by:

(A) Monosomy X


(B) Trisomy 21


(C) Trisomy 18


(D) Polyploidy




20. Turner syndrome individuals have chromosome complement:

(A) XO


(B) XY


(C) XX


(D) XXX




21. Klinefelter syndrome is represented by:

(A) XO


(B) XXY


(C) XXX


(D) XYY




22. Structural changes in chromosomes include:

(A) Polyploidy


(B) Deletion


(C) Aneuploidy


(D) Trisomy




23. Loss of a chromosome segment is called:

(A) Duplication


(B) Inversion


(C) Translocation


(D) Deletion




24. Reversal of chromosome segment is termed:

(A) Duplication


(B) Deletion


(C) Translocation


(D) Inversion




25. Exchange of segments between non-homologous chromosomes is called:

(A) Duplication


(B) Translocation


(C) Inversion


(D) Deletion




26. Chromosome duplication results in:

(A) Loss of genes


(B) Chromosome loss


(C) Gene inversion


(D) Extra gene copies




27. A chromosome with two centromeres is known as:

(A) Acentric


(B) Dicentric


(C) Polycentric


(D) Holocentric




28. Holocentric chromosomes have:

(A) No centromere


(B) One centromere


(C) Diffuse centromere


(D) Centromere at ends




29. Chromosomal aberrations can be detected using:

(A) Karyotyping


(B) Light microscopy


(C) PCR


(D) Western blot




30. Barr body represents:

(A) Active X chromosome


(B) Autosome


(C) Y chromosome


(D) Inactive X chromosome




31. Number of Barr bodies equals:

(A) Number of X chromosomes


(B) Y chromosomes


(C) X chromosomes minus one


(D) Autosomes




32. Chromatin that stains lightly is called:

(A) Euchromatin


(B) Heterochromatin


(C) Chromomere


(D) Kinetochore




33. Highly condensed and inactive chromatin is known as:

(A) Euchromatin


(B) Heterochromatin


(C) Chromatid


(D) Centromere




34. Chromosome pairing occurs during:

(A) Mitosis


(B) Meiosis I


(C) Meiosis II


(D) Interphase




35. Synapsis occurs during which stage?

(A) Leptotene


(B) Diplotene


(C) Pachytene


(D) Zygotene




36. Crossing over takes place during:

(A) Leptotene


(B) Pachytene


(C) Zygotene


(D) Diakinesis




37. Visible evidence of crossing over is called:

(A) Synapsis


(B) Tetrad


(C) Chiasma


(D) Bivalent




38. A bivalent consists of:

(A) One chromosome


(B) Two chromatids


(C) Four cells


(D) Two homologous chromosomes




39. Tetrad formation occurs due to:

(A) DNA replication


(B) Chromosome duplication


(C) Pairing of homologous chromosomes


(D) Cell division




40. Sex chromosomes in humans are:

(A) XX and XY


(B) XY only


(C) XX only


(D) XO




41. Autosomes in humans are:

(A) 24 pairs


(B) 23 pairs


(C) 21 pairs


(D) 22 pairs




42. The smallest human chromosome is:

(A) Chromosome 1


(B) Chromosome Y


(C) Chromosome X


(D) Chromosome 21




43. Polytene chromosomes are found in:

(A) Human neurons


(B) Plant roots


(C) Liver cells


(D) Salivary glands of Drosophila




44. Lampbrush chromosomes are observed during:

(A) Oogenesis


(B) Spermatogenesis


(C) Mitosis


(D) Fertilization




45. Satellite chromosomes possess:

(A) Extra centromere


(B) Extra genes


(C) Two telomeres


(D) Secondary constriction




46. Kinetochore is associated with:

(A) Centromere


(B) Telomere


(C) Chromatid


(D) Chromomere




47. Chromosomal mutations are also called:

(A) Gene mutations


(B) Structural aberrations


(C) Point mutations


(D) Silent mutations




48. Numerical chromosome changes affect:

(A) Gene sequence


(B) Chromosome number


(C) Protein structure


(D) Enzyme activity




49. Euploid condition refers to:

(A) Normal chromosome sets


(B) Abnormal chromosome number


(C) Missing chromosome


(D) Extra chromosome




50. Cytogenetic analysis is mainly useful for studying:

(A) Metabolic pathways


(B) Protein synthesis


(C) Enzyme kinetics


(D) Chromosomal abnormalities




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