26 Questions
What is the function of DNA supercoiling and condensation during metaphase?
To facilitate distribution into daughter cells
How many pairs of autosomes are there in humans?
22
What is the term used to describe members of a pair of chromosomes carrying the same genes in the same locus?
Homologous chromosomes
Which of the following tissues is NOT commonly used for chromosome analyses?
Muscle tissue
What is the purpose of adding colcemid during the harvesting process of chromosome isolation?
To prevent mitotic spindle formation
Which technique is preferred for identifying chromosomal polymorphisms?
Selective staining (C, NOR)
What is the main purpose of spreading chromosomes on glass slides during slide preparation?
To create a karyogram
What is the purpose of using hypotonic shock during the harvesting process of chromosome isolation?
To fix the chromosomes
Which technique is used for assessing chromosome structure, morphology, and number in routine diagnostics?
Giemsa stain
What is the purpose of using colcemid during the harvesting process of chromosome isolation?
To prevent mitotic spindle formation
What is the term used to describe the study of chromosomes and their inheritance?
Cytogenetics
Which of the following tissues is not commonly used for chromosome analyses?
Muscle tissue
What is the term used to describe the diploid chromosome number in humans?
Diploid
What is the term used to describe members of a pair of chromosomes carrying the same genes in the same locus?
Homologous chromosomes
What is the purpose of adding colcemid during the harvesting process of chromosome isolation?
To prevent mitotic spindle formation
Which technique is used for assessing chromosome structure, morphology, and number in routine diagnostics?
Giemsa stain
What is the main purpose of hypotonic shock during the harvesting process of chromosome isolation?
To swell the cells and release the chromosomes
Which banding technique is preferred for identifying chromosomal polymorphisms?
C banding
What is the term used to describe structural rearrangements involving a portion of a chromosome lost or deleted?
Deletion (del)
Which of the following is NOT a component required for preparing culture medium for cell culture techniques?
Chloroform
What is the temperature typically used for incubation during chromosome isolation from blood samples?
+37°C
Which type of cells are obtained for chromosome isolation using the direct method?
Peripheral blood cells
What is the purpose of staining with various banding techniques during slide preparation?
To evaluate chromosomes in a karyogram
What is the term used to describe members of a pair of chromosomes carrying different genes at the same locus?
Heterologous chromosomes
What is the abbreviation used to describe a case where a portion of a chromosome has been duplicated and inserted into another chromosome?
Translocation (t)
What is the primary purpose of solid stained metaphase and ideogram in chromosome analysis?
To assess chromosome structure and morphology
Study Notes
-
Chromosome isolation: using direct method, chromosomes are obtained from dividing cells, like bone marrow cytotrophoblastic cells
-
Culture techniques: short term culture (peripheral blood, bone marrow) and long term culture (amniotic cells, skin, solid tumor)
-
Preparing culture medium: medium, fetal calf serum, certain amino acids, antibiotics
-
Incubation: 37°C, 3 days for blood samples, medium changing only for long term cultures
-
Harvesting: colcemid added to prevent mitotic spindle formation, hypotonic shock, fixation with methanol:acetic acid (Carnoy fix), washing with fresh fixative
-
Slide preparation: spreading chromosomes on glass slides, staining with various banding techniques (G, Q, R, C, NOR, SCE, HRB, FISH)
-
Evaluation: chromosomes arranged in a karyogram, 22 autosomes and sex chromosomes in pairs, classified based on length and centromere position (Denver classification)
-
Banding techniques: 1) differential banding (G, Q, R) for assessing chromosome structure, morphology, and number; preferred for routine diagnostics and 2) selective staining (C, NOR) for identifying chromosomal polymorphisms.
-
Other banding techniques (Solid stained metaphase, ideogram)
-
Karyotype designation: chromosome number, sex chromosomes, abnormalities (if any)
-
Abbreviations for chromosome abnormalities: del, der, dic, dup, inv, mar, r, t, 45,XX,-7, 46,X,r(X), etc.
-
Techniques: Trypsin, Giemsa stain, Quinacrine, Acridine orange, Alkali treatment, FISH.
-
Chromosome isolation: using direct method, chromosomes are obtained from dividing cells, like bone marrow cytotrophoblastic cells
-
Culture techniques: short term culture (peripheral blood, bone marrow) and long term culture (amniotic cells, skin, solid tumor)
-
Preparing culture medium: medium, fetal calf serum, certain amino acids, antibiotics
-
Incubation: 37°C, 3 days for blood samples, medium changing only for long term cultures
-
Harvesting: colcemid added to prevent mitotic spindle formation, hypotonic shock, fixation with methanol:acetic acid (Carnoy fix), washing with fresh fixative
-
Slide preparation: spreading chromosomes on glass slides, staining with various banding techniques (G, Q, R, C, NOR, SCE, HRB, FISH)
-
Evaluation: chromosomes arranged in a karyogram, 22 autosomes and sex chromosomes in pairs, classified based on length and centromere position (Denver classification)
-
Banding techniques: 1) differential banding (G, Q, R) for assessing chromosome structure, morphology, and number; preferred for routine diagnostics and 2) selective staining (C, NOR) for identifying chromosomal polymorphisms.
-
Other banding techniques (Solid stained metaphase, ideogram)
-
Karyotype designation: chromosome number, sex chromosomes, abnormalities (if any)
-
Abbreviations for chromosome abnormalities: del, der, dic, dup, inv, mar, r, t, 45,XX,-7, 46,X,r(X), etc.
-
Techniques: Trypsin, Giemsa stain, Quinacrine, Acridine orange, Alkali treatment, FISH.
Test your knowledge on chromosomes, their structure, and functions with this quiz. Learn about chromosome number and their characteristics in humans.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
