This set of Cell Biology Multiple Choice Questions & Answers (MCQs) focuses on “Cancer – Genetics”.
1. Cancer is monoclonal.
Explanation: Cancer is termed monoclonal because the malignancy arises from one wayward cell that starts to divide indefinitely. Cancer is unlike other diseases that require modification of a large number of cells.
2. The most common solid tumors – breast, colon etc. arise in _____________ cells.
c) nerve cells
d) muscle cells
Explanation: Since tumors usually arise from cells that have indefinite capacity to divide, solid tumors usually arise from the epithelial cells that are engaged in high level of cell division.
3. Leukemias usually arise from _______________________
a) epithelial cells
c) blood-forming tissues
d) epidermal cells
Explanation: Leukemias usually arise from rapidly dividing blood forming tissues. The cells of blood-forming tissues can be divided into three categories – stem cells, progenitor cells, and differentiated cells.
4. The expression of telomerase on cancer cells can be considered an epigenetic change.
Explanation: The expression of telomerase on cancer cells can be considered an epigenetic change. Epigenetics changes are the one that results from activation of a gene that generally remains repressed.
5. Which of the following is a test for detecting precancerous cells?
b) CT Scan
c) Pap smear
Explanation: Pap smear is a test used to identify precancerous cells in the epithelial lining of the cervix. The precancerous cells have a morphology that is switched and doesn’t look like the normal cells.
6. Oncogenes promote the growth of cancer cells.
Explanation: Oncogenes encode for the proteins that promote loss of growth control and other associated roles, which subsequently leads to the conversion of normal cells into malignant cells.
7. Proto-oncogenes are possessed by the ______________________
a) RNA virus
b) DNA virus
c) Cells themselves
d) Pathogenic bacteria
Explanation: Proto-oncogenes are the genes present in cells themselves, these genes have the ability to avert a normal cell into a cancerous one. The initial event that led to the discovery of proto-oncogenes was made in 1976 when src gene from avian sarcoma virus was identified.
8. The oncogenes act __________________
Explanation: The oncogenes act dominantly, that is, the presence of a single copy of an oncogene can lead the cell to develop an altered phenotype that might be present. Regardless of whether there is a normal copy of the gene present on homologous chromosome, the oncogenes can express themselves.
9. The first tumor-suppressor gene to be studied is associated with ______________________
Explanation: The first tumor-suppressor gene to be studied is associated with retinoblastoma – a rare childhood cancer of the retina. The incidence of this disease follows a distinct two patterns: it occurs in children of certain families and sporadically at an older age.
10. When was the genetic basis of retinoblastoma first explained?
Explanation: The genetic basis of retinoblastoma was first explained in 1971 by Alfred Knudson at the University of Texas. Unlike other dominant genetic disorders, the carriers of gene responsible for retinoblastoma only develop a strong disposition towards developing the disease, rather than inheriting the disease itself.
11. For the development of cancer, which of the following is the most influential component of the genome?
b) Cytochrome c
Explanation: The TP53 gene encodes for the protein p53 – a polypeptide having a mass of 53,000 daltons. In 1970 it was regarded as a tumor-suppressor gene which when absent can lead to Li-Fraumeni syndrome.
12. p53 is a _____________________
a) translation factor
d) transcription factor
Explanation: p53 is a transcription factor that activates the expression of a wide array of proteins responsible for cell cycle regulation and apoptosis. There are six most common mutations in human cancers that are required for disabling the p53.
13. p53 is capable of binding to which family of proteins?
Explanation: p53 is a transcription factor that activates the expression of proteins involved in cell cycle regulation and apoptosis. In addition to that, it can also bind directly to the Bcl-2 family of proteins and initiate apoptosis.
Sanfoundry Global Education & Learning Series – Cell Biology.
To practice all areas of Cell Biology, here is complete set of 1000+ Multiple Choice Questions and Answers.