Question 1

The process of cell division is called:

Accepted Answer

The process of cell division is called mitosis, in which one cell divides into two identical daughter cells with the same number of chromosomes. Meiosis is a specific type of cell division that occurs in sexually reproducing organisms, where the cells divide twice to produce four haploid cells with half the number of chromosomes. The cell cycle refers to the series of events that occur in a cell's life, including growth, replication of DNA, and cell division. Allele is a term used in genetics to describe different versions of a gene.

Question 2

Which of the following represents the location of the chromosomes during metaphase?

Accepted Answer

During metaphase, the chromosomes align in the center of the cell along the metaphase plate. This is necessary for proper separation of the chromosomes during subsequent stages of mitosis. They are not located in the nucleolus or on opposite poles of the cell during metaphase.

Question 3

During the harvesting phase of sample preparation, the cells are arrested in metaphase by:

Accepted Answer

Incubation with colchicine is commonly used to arrest cells in metaphase by disrupting the assembly and function of the mitotic spindle. This allows for easier chromosome visualization and harvesting. Fixing with Carnoy's fixative can also be used for chromosome preparation, but it does not arrest the cells in metaphase. Incubation with KCl can be used to swell cells and increase chromosome visibility, but it also does not arrest the cells in metaphase. Addition of phytohemagglutinin can be used to stimulate lymphocyte division, but it is not usually used for chromosome preparation.

Question 4

Which of the following is an appropriate specimen source for cytogenetic analysis?

Accepted Answer

A source with nucleated cells that can be manipulated into mitosis is the most appropriate specimen source for cytogenetic analysis because cytogenetic analysis requires the visualization and analysis of chromosomes during mitosis. A source that contains nucleated cells that can be easily stimulated to undergo mitosis, such as peripheral blood lymphocytes or bone marrow cells, is often used for cytogenetic analysis.

Question 5

A laboratory professional should process a bone marrow aspirate for cytogenetic analysis in a patient with a lymphoma by using which of the following?

Accepted Answer

Direct harvest is the method of choice for processing bone marrow aspirate for cytogenetic analysis in patients with lymphoma. It involves the direct harvesting of cells from the aspirate and processing them without the need for tissue culture or mitogen stimulation, which can introduce artifacts or alter the karyotype. Suspension tissue culture can also be used, but it is not the best choice as it can also introduce artifacts.

Question 6

Which of the following structural aberrations results in loss of an entire chromosomal arm?

Accepted Answer

An isochromosome results in the loss of one arm of a chromosome and the duplication of the other arm, effectively leading to the loss of an entire chromosomal arm.

Question 7

Why would a bone marrow aspirate be needed as a specimen for cytogenetic analysis in a patient with a lymphoma?

Accepted Answer

The answer of Why would a bone marrow aspirate be...

Question 8

A 42-year-old female patient has a solid tumor in her left lung. The physician has ordered cytogenetic analysis. What type of specimen is needed?

Accepted Answer

Pleural effusion is the correct type of specimen for cytogenetic analysis in the case of a lung tumor, as it can contain cells shed from the tumor itself, providing valuable information for diagnosis and treatment planning.

Question 9

Incubation with ________ stops rapid cell division in metaphase and occurs ________ incubation in hypotonic solution.

Accepted Answer

The question is asking for a substance that stops rapid cell division in metaphase and occurs before incubation in hypotonic solution. Colchicine is a drug that specifically targets microtubules and halts cell division in metaphase. Therefore, it is the best choice for this scenario.

Question 10

A 60-year-old patient was admitted to the local hospital presenting with petechiae on his upper torso. Physical examination revealed a thin, pale man. Admission labs came back, and the results revealed the presence of 50% blasts and 25% hypergranular promyelocytes. A bone marrow aspirate was ordered that confirmed the peripheral blood picture. Cytogenetic analysis revealed the following: t (11; 17) (q23; q21). How does this impact the patient's care?

Accepted Answer

The t(11;17) translocation is associated with a variant of acute promyelocytic leukemia that is resistant to all-trans retinoic acid (ATRA), necessitating alternative treatments.

Question 11

What is the main difference between nondisjunction and anaphase lag?

Accepted Answer

The main difference between nondisjunction and anaphase lag is the outcome in terms of chromosome number. Nondisjunction can result in both trisomy and monosomy, while anaphase lag only results in a single monosomy.

Question 12

The cell cycle contains four phases: G1, S, G2, and mitosis. Which phase must be active to study human chromosomes?

Accepted Answer

Chromosomes are only visible during mitosis, specifically during metaphase when they align in the center of the cell. Therefore, mitosis must be active to study human chromosomes.

Question 13

Cytogenetic analysis focuses on:

Accepted Answer

Cytogenetic analysis specifically focuses on analyzing the structure and number of chromosomes, making chromosome assessment the best choice. Evaluation of the cell cycle may be part of cytogenetic analysis, but it is not the primary focus. Mitotic rates refer to the frequency at which cells are undergoing cell division and are not directly related to cytogenetic analysis. Quantitation of alleles is more relevant to molecular genetics analysis.

Question 14

The chromosome abnormality type that results in a daughter cell with an extra chromosome-or trisomy-or a daughter cell with a loss of chromosome is characterized as which of the following?

Accepted Answer

The type of chromosome abnormality described in the question is numerical aberration, where there is either an extra chromosome (trisomy) or a loss of chromosome (monosomy) in the daughter cell. Constitutional aberrations refer to genetic mutations that are present in all cells of an individual's body, while mosaic aberrations refer to mutations that occur in only some cells. Structural aberrations involve changes in the structure of chromosomes, such as deletions, inversions, or translocations. Acquired aberrations are mutations that occur after fertilization, such as mutations that lead to cancer.

Question 15

A patient is receiving chemotherapy for Hodgkin lymphoma. When the treatment ends, a cytogenetic analysis is ordered to determine whether the treatment was successful. Which of the following would be the most appropriate specimen to collect for this?

Accepted Answer

Lymphoid tissue would be the most appropriate specimen to collect for cytogenetic analysis to determine the success of chemotherapy for Hodgkin lymphoma, as this is the tissue affected by the disease. Bone marrow or peripheral blood may also be useful, but would not necessarily provide as accurate of a representation of the success of the treatment. Skin biopsy would not be relevant in this case.

Question 16

Which of the following terms is used to describe a chromosomal aberration present in a human cell that is a multiple of n?

Accepted Answer

Polyploidy is used to describe a chromosomal aberration in a human cell that is a multiple of n, where n represents the normal diploid number of chromosomes in a cell. Trisomy refers to the presence of an extra copy of a single chromosome in a diploid cell, while aneuploidy refers to an abnormal number of chromosomes that is not a multiple of the normal diploid number. Diploid refers to the normal number of chromosomes in a human cell, which is 46.

Question 17

A 3-year-old girl is confirmed to have ALL by immunophenotyping. She is positive for the CALLA antigen. Cytogenetic analysis results indicate the presence of the Philadelphia chromosome. Which of the following applies to her?

Accepted Answer

The presence of the Philadelphia chromosome is a poor prognostic indicator in ALL patients. The Philadelphia chromosome is a translocation between chromosomes 9 and 22 that produces the BCR-ABL1 fusion protein, which has tyrosine kinase activity and promotes cell division and inhibition of apoptosis. Targeted therapy with tyrosine kinase inhibitors is effective in patients with the Philadelphia chromosome, but the overall prognosis for these patients is still poor compared to those without the chromosome. The presence of the CALLA antigen is a common finding in ALL and does not affect prognosis. An atypical presentation would be indicated by unusual clinical or laboratory findings, which are not mentioned in the question stem.

Question 18

Which specimen would be optimal for studying lymphoma?

Accepted Answer

Lymphoma is a cancer of the lymphatic system, which includes lymph nodes, spleen, thymus, and bone marrow. Therefore, the optimal specimen for studying lymphoma would be an involved lymph node as it will contain the cancerous cells or tissue. Peripheral blood and amniotic fluid would not provide adequate information about lymphoma, while solid tumor biopsy may not necessarily represent the entire disease process.

Question 19

Which of the following chromosomal aberrations is associated with Burkitt lymphoma?

Accepted Answer

Burkitt lymphoma is associated with t(8;22)(q24.1;q11.2), which results in the activation of the MYC oncogene. A is the translocation associated with chronic myelogenous leukemia, B is associated with myelodysplastic syndrome and acute myeloid leukemia, and D is not a known aberration associated with Burkitt lymphoma.

Question 20

Which of the following can result in trisomy?

Accepted Answer

Trisomy is a condition where there are three copies of a particular chromosome instead of the normal two copies. Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate during meiosis, resulting in an abnormal number of chromosomes in the daughter cells. If nondisjunction occurs during meiosis, it can result in the production of gametes with an extra copy of a chromosome, which can lead to trisomy when fertilization occurs. Anaphase lag, chromosome banding, and endomitosis are not directly related to trisomy.

Quiz 41: Chromosome Analysis of Hematopoietic and Lymphoid Disorders