1. Which of the following condition is preferential target for carcinogen binding?
a) DNA in transcribing regions associated with the nuclear matrix
b) DNA in replicating region associated with nuclear matrix
c) DNA in translational region associated with cytoplasmic region
d) DNA in translational region in mitochondria matrix
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Explanation: The base sequence of DNA determines the specificity of carcinogen binding. The location within the nucleus, for example nuclear matrix and chromatin structure also favours the same.
2. Which malignancies are the exception to the fact that cancer incidence increases with age?
a) Leukaemia and sarcoma
b) Lymphoma and sarcoma
c) Retinoblastoma and Lymphoma
d) Carcinoma and Retinoblastoma
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Explanation: Mostly adult solid tumors begin to increase logarithmically after the age of 45. Leukemia is the cancer of blood or bone marrow and most common type of cancer in children. Whereas, rhabdomyosarcoma (RMS) is the major reason of soft tissue sarcoma in children.
3. Which species was first observed for inducing cancer chemically?
a) Hamster
b) Mice
c) Humans
d) Chickens
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Explanation: In 1761, John Hill noted that people who used snuff excessively were diagnosed with nasal cancer. Similarly, observations were made establishing a relationship between certain chemicals and cancer.
4. Which of the following compounds do not require enzymatic activation for carcinogenic action?
a) Dialkylnitrosamines and dialkylhydrazines
b) Alkylnitrosimides and alkylnitrosamides
c) Alkylhydrazines and alkyltriazenes
d) Alkyltriazenes and alkylnitrosamides
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Explanation: Alkylnitrosimides and alkylnitrosamides attach directly with water or cellular nucleophilic groups for carcinogenic action. However, Dialkylnitrosamines, dialkylhydrazines and alkyltriazenes require to go through enzyme mediated activation step to form reactive electrophile for carcinogenic action.
5. For RAS mutations, the majority of mutations are in which amino acid transition?
a) A-T
b) G-C
c) T-G
d) G-A
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Explanation: About 43% of K-Ras mutation patterns are G-A transitions. These second base of codon 12 or 13 results in G12D and G13D mutation which occurs due to this transition.
6. Which location in exons are considered to be the hot spots for point mutation?
a) Exons 4 – 9
b) Exons 5 – 8
c) Exons 3 – 6
d) Exons 7 – 11
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Explanation: p53 gene is inactivated during carcinogenesis. The mutations of this gene is generally point mutations occurring in “hot spots” in exons 5 – 8, which is considered as most conserved regions in these exons found in animal tumors as well as human cancer.
7. Carcinogenesis is a multistage process occurring in which sequence?
a) A lag time, initiation, promotion, and tumor progression
b) A lag time, promotion, Initiation and tumor progression
c) Initiation, a lag time, promotion, and tumor progression
d) Initiation, promotion, a lag time, and tumor progression
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Explanation: Carcinogenesis starts with initiation which increases leading to lag phase invading other cells. These tumor promotes and progresses to form tumor.
8. Which is the correct sequence for possible five-hit scenario for colorectal Cancer?
a) Two APC mutations Adenomatous polyp: one RAS mutation-Dysplastic polyp: two TP53 mutations-Colon carcinoma- Metastatic carcinoma
b) Dysplastic polyp: two TP53 mutations-two APC mutations Adenomatous polyp: one RAS mutation- Metastatic carcinoma-Colon carcinoma
c) Dysplastic polyp: two TP53 mutations- Metastatic carcinoma- Colon carcinoma- Two APC mutations Adenomatous polyp: one RAS mutation
d) Colon carcinoma- two APC mutations Adenomatous polyp: one RAS mutation-Dysplastic polyp: two TP53 mutations- Metastatic carcinoma
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Explanation: When APC gene is inactivated in migrating cell, it could reverse differentiation process tricking the cell to think that it is immortal. This leads to continued proliferation of cells forming metastatic carcinoma.
9. Arsenic metals leads to which type of cancer?
a) Prostate and kidney
b) Kidney and Lungs
c) Stomach and Liver
d) Lung and Skin
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Explanation: International Agency For Research on Cancer classifies Arsenic as carcinogenic to humans. Arsenic ingestion is the cause of most common form of neoplasm causing skin cancer, whereas lung cancer is deadly.
10. Which of the following natural carcinogen affects Liver?
a) Asbestos
b) Aflatoxin B1
c) Melphalan
d) Thiotepa
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Explanation: Aflatoxin is a type of mycotoxin found in contaminated food which leads to Liver cancer. Asbestos is a naturally occurring silicate which affects Lung. Melphalan and Thiotepa are anti-cancer drugs.
Cancer Biology MCQ on Causes of Cancer
11. Which of the following compound appears to be the carcinogen in vivo by sulfotransferase activity?
a) AAF
b) N-hydroxy-AAF
c) N-sulfonoxy-AAF
d) N-acetoxy-AAF
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Explanation: N hydroxy-AAF is converted to N sulfonoxy AAF by cytosol sulfotransferase activity in rat liver which reacts with proteins and nucleic acids. This compound proved to be carcinogenic in vivo. Whereas, AAF and N-hydroxyl-AAF did not react with nucleic acids or proteins.
12. Which of the following compound appears to be the carcinogen in vivo by acetyltransferase mediated activity?
a) N-hydroxy-AAF
b) N-acetoxy-2-aminofluorene
c) N-acetoxy-AAF
d) AAF
View Answer
Explanation: N-hydroxy-AAF is converted to N-acetoxy-2-aminofluorene by acetyltransferase mediated activity. N-acetoxy-2-aminofluorene is a strong electrophile and maybe ultimate carcinogen in nonhepatic tissues.
13. What is the correct series for molecular genetic events that happens as the radiation damages the cell?
a) Induction of c-jun and Egr-1- Tumor necrosis factor-a (TNF-a) – Interleukin-1 (IL-1) PKC- c-myc and K-ras
b) Induction of c-jun and Egr-1- Tumor necrosis factor-a (TNF-a) – c-myc and K-ras- Interleukin-1 (IL-1) PKC
c) Induction of c-jun and Egr-1- Interleukin-1 (IL-1) PKC- Tumor necrosis factor-a (TNF-a) – c-myc and K-ras
d) c-myc and K-ras- Induction of c-jun and Egr-1- Tumor necrosis factor-a (TNF-a)- – Interleukin-1 (IL-1) PKC
View Answer
Explanation: Damage due to radiation in cells include the molecular genetic events which are in longer-range effects and leads to carcinogenesis. The molecular genetic events are follows:
Induction of c-jun and Egr-1 as early-response genes
Induction of tumor necrosis factor-a (TNF-a), fibroblast growth factor (FGF), and platelet-derived growth factor-a (PDGF-a) as later-response genes
Activation of interleukin-1 (IL-1) PKC110; and
Activation and induction of oncogenes such as c-myc and K-ras.
14. Irradiation with UV-B leads to which damage?
a) Pyrimidine dimers
b) Purine dimers
c) Oxidative lesions
d) Base translocation
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Explanation: Although UV-B is important for production of Vitamin D in skin, its irradiation leads to cyclobutane pyrimidine dimers. The Nucleotide excision repair mechanism is used to repair these dimer, which if left unrepaired can lead to C-T or CC-TT base transition.
15. Irradiation with UV-A leads to which damage?
a) Purine dimers
b) Pyrimidine dimers
c) Oxidative lesions
d) Base translocation
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Explanation: Nearly all the radiation which reach Earth is absorbed by ozone layer and most of UV radiation that reach us is UV-A. Its irradiation can stimulate oxidative lesions through photosensitization mechanism.
16. The alteration of 8-Hydroxyguanine altered base, with which left unrepaired can lead to which mutation?
a) G-T transversion
b) G-T translocation
c) A-T point mutation
d) C-G point mutation
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Explanation: Oxidative damage to DNA stimulates the alteration of 8-Hydroxyguanine base. If this damage is not repaired, it leads to G-T transversion.
17. Which of the following rays have very low risk of causing mutation that can lead to cancer?
a) Ionising radiation
b) Ultraviolet radiation
c) Electromagnetic fields
d) X-rays
View Answer
Explanation: Electromagnetic fields are unable to directly cause DNA mutation as the energy exposed by it is too little to change the structure of molecules. Whereas ionising radiation, X-rays and UV radiation damage living tissues leading to DNA mutation which can cause cancer.
18. Which of the following natural isotope of Potassium is not radioactive?
a) 42K
b) 39K
c) 40K
d) 41K
View Answer
Explanation: Potassium is the chief radioactivity emitter in our bodies. 39K, 40K and 41K are the natural isotopes among which 39K and 41K are in stable form. 40K isotope is radioactive with half-life of 1.3 billion years. 40K isotope make up only 0.012% of our potassium.
19. Which among the following makes up for the World’s major source of ionising radiation?
a) Radon
b) Actinium
c) Neptunium
d) Polonium
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Explanation: Radon is product of Radium which is the major source of ionising radiation in most parts of the world. Radon-222 has half-life of 4 days. Radon is the source of alpha particles, being one of the cause for lung cancer.
20. BRCA1 and BRCA2 can cause which cancer?
a) Mammary adenocarcinomas
b) Colorectal adenomas
c) Skin tumours
d) Lung adenocarcinomas
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Explanation: Mammary adenocarcinomas are developed due to mutation in BRCA1 and BRCA2 genes. BRCA1 and BRCA2 are responsible for DNA repair and mutation in these gene leads to mutation causing cancer.
21. Which among the following is important in DNA replication and DNA repair?
a) Calcium
b) Folate
c) Fibre
d) Iron
View Answer
Explanation: Folate is a type of Vitamin B which helps to transport carbon atoms around when building blocks of DNA and proteins are made. Therefore, it is important in DNA damage and repair mechanism. The synthetic form of folate i.e. Folic acid is used as food supplement to avoid shortage of folate.
22. Which of the following bacteria has the potential to double the risk of developing gastric cancer?
a) Salmonella
b) Listeria monocytogenes
c) Escherichia coli
d) Helicobacter pylori
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Explanation: Helicobacter pylori spreads by consuming food or water contaminated with faecal matter. This bacteria gives rise to chronic infection and ulcers in stomach, doubling the risk of gastric cancer.
23. Which among the following cancer is easy to detect at an early stage?
a) Melanoma
b) Sarcoma
c) Lymphoma
d) Leukemia
View Answer
Explanation: Malignant melanomas arises from moles on skin and leads to the change in colour size or shape. Thus they are easiest to detect at an early stage. Melanomas if identified early can be treated with the help of surgery alone.
24. Which phase of women is very much susceptible to cause Breast cancer?
a) During menstruation
b) Pre-menstrual
c) Post-Menopause
d) Post menstruation
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Answer: The Post-menopausal phase in women is more significant for the risk of breast cancer. After menopause fat tissues makes oestrogen as ovaries stop making it. Having more fat tissues can lead to increase in oestrogen levels, increasing the risk of breast cancer.
25. Which cancer is caused due to BCR-ABL1 oncogene?
a) B-cell Leukemia
b) Sarcoma
c) T-cell lymphoma
d) Melanoma
View Answer
Explanation: BCR-ABl1 oncogene is responsible for Leukemia cancer having three isoforms of p190, p210 and p230. Among these p190 leads to B-cell acute lymphoblastic leukemia.
Cancer Biology MCQ on Viral Carcinogenesis
26. Which Virus is responsible for Adult T-cell leukemia?
a) HTLV-1
b) HBV
c) HCV
d) EBV
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Explanation: HTLV-1 is a positive strand single-stranded RNA retrovirus which is responsible for Adult T-cell Leukemia. ATL is a cancer of CD4+ T lymphocytes. It leads to severe immunodeficiency and is resistant to intensive chemotherapies.
27. Which among the following carcinoma is related to Hepatitis C virus?
a) Hepatocellular carcinoma
b) Sarcoma
c) Retinoblastoma
d) B-Leukemia
View Answer
Explanation: Hepatocellular carcinoma is the most common type of primary liver cancer. HCV is a positive strand RNA flavivirus which is responsible for hepatocellular carcinoma. HCV can cause inflammation in liver leading to cirrhosis and then the lung cancer.
28. Which virus is responsible for malignancy among AIDS patients?
a) KSHV
b) MCV
c) EBV
d) MCV
View Answer
Explanation: Kaposi’s sarcoma Herpes Virus is a double stranded DNA virus. Among the other virus, Kaposi’s sarcoma is the most frequent reason for malignancy among AIDS patients.
29. Which among the following cancer is caused by MCV?
a) Lung cancer
b) Brain cancer
c) Skin cancer
d) Liver cancer
View Answer
Explanation: MCV is a double stranded DNA polymovirus which leads to Merkel cell carcinoma (MCC). MCC is a rare human skin cancer in an aggressive form which affects immunosuppresses individuals as well as elderly people.
30. Which among the following cancer is caused by EBV?
a) T cell leukemia
b) B cell leukemia
c) Gastric cancer
d) Burkitt’s lymphoma
View Answer
Explanation: Epstein Barr Virus (EBV) is a double stranded DNA herpes virus. It has the potential to cause Burkitt’s lymphoma as well as nasopharyngeal carcinoma.
31. Which type of cancer is linked with Hepatitis B virus?
a) Retinoblastoma
b) Hepatocellular carcinoma
c) T cell lymphoma
d) T cell leukemia
View Answer
Explanation: Hepatitis B virus have retroviral features and is partially double stranded DNA hepadnavirus. Chronic infection with HBV can lead to Hepatocellular carcinoma (HCC). Development of HCC due to HBV has been linked for over 30 years.
32. Which among the following cancer is not linked with Human Papilloma Virus?
a) Leukemia
b) Penile cancer
c) Cervical cancer
d) Head and neck cancer
View Answer
Explanation: Human papillomavirus (HPV) is a group of circular double stranded DNA. Although other α-HPV are also carcinogenic, HPV16 and HPV18 are responsible for penile cancer, cervical cancer, and head and neck cancer.
33. Which among the following chromosome is not involved in chromosomal mutation causing Hepatocellular carcinoma?
a) Chromosome 11
b) Chromosome 17
c) Chromosome 12
d) Chromosome 13
View Answer
Explanation: Some chromosomal alteration is seen in Hepatocellular carcinoma. These chromosomal alterations occur in short arm of chromosome 11, point mutation of p53 gene on chromosome 17 and deletion in long arm i.e. q arm of chromosome 13.
34. Which among the following HPV is responsible for most of cervical cancer?
a) HPV18
b) HPV31
c) HPV33
d) HPV16
View Answer
Explanation: HPV16, HPV18, HPV33 and HPV31 are responsible for 90% of all cases of cervical cancer. Among all these high risks HPVs, HPV16 accounts for more than 50% of all cases of cervical cancer and thus is the most prevalent type.
35. Which microorganism was first identified of inducing tumours in animals?
a) Virus
b) Bacteria
c) Fungi
d) Algae
View Answer
Explanation: Virus were first identified for inducing tumours in animals or transforming cell in culture, thus leading to identification of oncogenes. The experiment was conducted by Peyton Rous which showed that cell free filtrates from chicken tumours were capable of giving rise to sarcoma when inoculated in normal tissues.
More MCQs on Cancer Biology:
