Explore topic-wise InterviewSolutions in .

Correct answer is (a) ANGIOGENESIS inhibitor

The best EXPLANATION: ENDOSTATIN is a NATURALLY occurring inhibitor of angiogenesis – the process of formation of new blood vessels. It is a 20 kilo Dalton fragment of C-terminal of Collagen XVIII, which specifically INHIBITS the proliferation of endothelial cells.

The correct CHOICE is (d) Herceptin

The explanation is: Herceptin is the commercial NAME for the monoclonal ANTIBODY Trastuzumab. It is used as a passive immunotherapy drug for HER2 positive cancer CELLS.

Right option is (a) True

To elaborate: Oncogenes are genes that can induce cancer in NORMAL cells by changing its genetic composition. They PROMOTE UNREGULATED GROWTH and malignancy as well as angiogenesis in some FORM of cancer.

Right answer is (c) TP53

The best I can EXPLAIN: 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.

Right ANSWER is (a) Chronic myelogenous leukemia

For explanation: Chronic myelogenous leukemia is caused by a chromosomal translocation that BRINGS together the proto-oncogene (ABL) in CONTACT with another GENE (BCR) to FORM a chimeric gene (BCR ABL).

Right answer is (d) G-proteins

The explanation is: ARRESTINS are a small GROUP of proteins that bind to the G-protein coupled receptors. To bind to these receptors, the arrestins compete with heterotrimeric G-proteins. In the PROCESS of DESENSITIZATION, arrestin binding PREVENTS further activation of the G-proteins.

The correct answer is (d) growth rate

To explain I would say: The normal CELLS tend to remain in SINGLE layer of cells, termed monolayer when their growth rate DECREASES. The decrease in growth rate is caused DUE to inhibitory INFLUENCES from the environment.

The CORRECT choice is (C) growth factors

The explanation: Cancer cells PROMOTE angiogenesis by SECRETING growth factors such as VEGF that act on the endothelial cells of surrounding blood vessels and stimulate them to proliferate and form new blood vessels.

Right option is (C) RETINOBLASTOMA

Explanation: The first tumour suppressor GENE was studied in retinoblastoma named as the Rb tumour suppressor gene. It was found to be useful in TREATING EARLY onset of retinoblastoma.

Right answer is (b) 1971

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.

Right choice is (a) True

Easy explanation: Certain agents or environmental factors such as HARMFUL rays, smoke from industries ETC. may not act as mutagens themselves. But, once they gain entry in the body, a conversion to mutagenic form might occur by the ACTION of cellular enzymes.

Correct answer is (a) True

Explanation: When cancer cells are grown in culture, unlike normal cells that form a SINGLE layer of cells, they form clumps by growing on top of ONE another in PILES. This is PROBABLY because cancer cells do not respond to the INHIBITORY signals coming from the environment.

Correct answer is (a) True

Easiest EXPLANATION: Conventional therapies of cancer such as surgery and CHEMOTHERAPY are not successful in TREATING metastatic CANCERS. These therapies ALSO target a large number of normal cells in addition to cancer cells.

Correct choice is (a) telomerase

To explain I would say: In CULTURE, the cancer cells possess the CAPABILITY of growing INFINITELY unlike normal cells that do not GROW beyond a certain number of mitotic divisions. This immortality exhibited by the cancer cells is due to the presence of enzyme telomerase.

Right answer is (a) True

To elaborate: Active immunotherapy, ALSO termed ADOPTIVE immunotherapy is aimed at involving the patient’s own IMMUNE system in the fight against CANCER, rather than administering any foreign drugs.

Right answer is (d) transcription FACTOR

To elaborate: P53 is a protein transcription factor that is also CALLED the guardian of the genome because of its role in tumour suppression by causing APOPTOSIS. p53 has also been used to TREAT onset of certain tumours.

Right answer is (a) COLON cancer

The best explanation: Long-term USE of nonsteroidal anti-inflammatory drugs (NSAIDs), for example, aspirin and indomethacin can DECREASE the risk of colon cancer. NSAIDs can evoke this EFFECT by inhibiting an ENZYME – cyclooxygenase-2.

Right option is (c) Pap smear

The EXPLANATION is: 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.

Correct answer is (c) apoptosis

The explanation is: The cancer cells are protected from apoptosis and usually do not activate a cell destruction PATHWAY even when there is a PRESENCE of ABERRANT chromosome NUMBER and inhibitory signals from the environment.

Right CHOICE is (a) True

To explain I would say: 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.

Right CHOICE is (a) epithelial

To explain I would say: 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.

Right option is (B) Antibodies

Easiest EXPLANATION: Passive or adoptive immunotherapy is the administration of antibodies that are SPECIFIC to a type of CANCER epitope. This allows the body to develop an immune response against the cancer.

Correct answer is (a) True

Best 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.

Correct choice is (a) carcinogenic COMPOUNDS

Easy explanation: Normal cells can be converted to CANCER cells by treatment with carcinogenic compounds (such as X-rays) that can induce mutations in the genome of normal cells, MAKING them malignant.

Right choice is (a) insulin, EPIDERMAL growth factor

Easy explanation: The TWO important compounds those are required for the culture of normal mammalian cells, are insulin and epidermal growth factor, present as COMPONENTS of the serum’s fluid fraction. However, these are not required for the CULTURING of cancer cells.

The correct choice is (b) False

For explanation I would SAY: CANCER is a genetic disease but it may not be NECESSARILY inherited. Most of the cases of cancer are not inherited and might arise due to poor LIFESTYLE and eating HABITS.

Right ANSWER is (b) Rituxan

The explanation is: Rituxan was approved in 1997 for the treatment of non-Hodgkin’s B-cell lymphoma. It binds to the cell-surface protein CD20 that is present on malignant B cells in 95 percent of cases of this DISEASE.

Right CHOICE is (b) William Coley

The EXPLANATION: The best studied cases of spontaneous remissions in cancer were recorded in the 1800s by a New York physician William Coley. He developed a bacterial extract which when injected could stimulate a PERSON’s IMMUNITY.

The CORRECT option is (a) dominantly

Easy 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.

The correct answer is (b) HIV

Explanation: The VIRUSES that can infect mammalian cells growing in culture and transform them into cancer cells, are divided into two categories – DNA viruses and RNA viruses, depending on the type of nucleic acid FOUND within the mature viral PARTICLE. Human immunodeficiency VIRUS (HIV) has a structure similar to RNA viruses.

The correct option is (b) prostaglandins

Explanation: Cyclooxygenase-2 is the ENZYME that synthesizes hormone-LIKE prostaglandins that promote the growth of intestinal POLYPS. Polyps are abnormal tissue growths that LOOK like flat bumps.

Correct answer is (C) BLOOD-forming tissues

To elaborate: 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.

Correct choice is (a) Helicobacter pylori

For explanation I WOULD say: Helicobacter pylori is a stomach-dwelling bacterium, CHRONIC INFECTION of which can lead to GASTRIC lymphomas and stomach ulcers. Helicobacter pylori was PREVIOUSLY known as Campylocater pylori.

Correct choice is (a) HERPES-virus

Easiest EXPLANATION: Kaposi’s sarcoma is a type of cancer in which patches of abnormal tissue grow under the skin. Herpes virus (HHV-8) is ASSOCIATED with the Kaposi’s sarcoma. The formal name of HHV ACCORDING to International Committee on Taxonomy of VIRUSES is Human gammaherpesvirus 8.

Correct answer is (b) blood vessels

The best explanation: ANGIOGENESIS is the process of the formation of new blood vessels. When a tumor grows in SIZE, its NUTRIENT requirements and METABOLISM also INCREASE and angiogenesis is initiated for its nourishment.