Cancer Questions in English

(D) Melanoma is a type of cancer that develops from melanocytes,which are the pigment-producing cells of the skin.
It often appears as a change in the size,shape,or color of an existing mole or the appearance of a new,unusual-looking growth on the skin.
Adenoma is a benign tumor of glandular tissue.
Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs.
Lymphoma is a cancer of the lymphatic system.

(B) Retroviruses are a group of viruses that contain $RNA$ as their genetic material. They possess an enzyme called reverse transcriptase,which allows them to convert their $RNA$ into $DNA$ inside the host cell. This viral $DNA$ then integrates into the host genome. Certain retroviruses,known as oncogenic retroviruses,carry viral oncogenes $(v-onc)$ or can activate host proto-oncogenes,which leads to the transformation of normal cells into cancerous cells.

(B) Contact inhibition is a regulatory mechanism that functions to keep the cells growing to a layer one cell thick (a monolayer).
Normal cells in the body exhibit this property,which prevents them from dividing uncontrollably when they come into contact with neighboring cells.
In contrast,cancer cells (neoplastic cells) lose this property,which allows them to continue dividing and piling up on top of each other,eventually forming a tumor.

(B) Certain viruses known as oncogenic viruses have genes called viral oncogenes that can cause the transformation of normal cells into cancerous cells. Among the given options,$Retroviruses$ are well-known for their ability to transform normal cells into cancerous cells through the action of their viral oncogenes $(v-onc)$.

(A) Biological response modifiers are substances that stimulate the body's immune system to fight cancer. $\alpha$-interferons are commonly used as biological response modifiers in cancer treatment because they help activate the immune system to destroy tumor cells.

(A) The correct answer is $A$.
$\alpha$-Interferon is a biological response modifier used in the treatment of cancer.
On the other hand,oncogenic viruses,proto-oncogenes (when mutated),and $UV$ rays are all classified as carcinogens or cancer-causing agents.
Therefore,$\alpha$-Interferon is the odd one out.

(D) The correct answer is $D$.
Techniques such as $CT$ (Computed Tomography),$MRI$ (Magnetic Resonance Imaging),and Radiology ($X$-rays) are widely used for the detection of cancers in internal organs.
$CT$ uses $X$-rays to generate a three-dimensional image of the internal organs.
$MRI$ uses strong magnetic fields and non-ionizing radiations to accurately detect pathological and physiological changes in the living tissue.
Therefore,all the listed techniques are useful for cancer detection.

(B) The correct answer is $B$. Metastasis is the most feared property of malignant tumors.
$1$. Malignant tumors consist of a mass of proliferating cells known as neoplastic or tumor cells.
$2$. These cells grow rapidly,invading and damaging the surrounding normal tissues.
$3$. As these cells actively divide,they can detach from the primary tumor and spread to distant organs of the body through the blood and lymph systems.
$4$. This process of spreading and developing secondary tumors at distant sites is called metastasis,which makes cancer difficult to treat and life-threatening.

(C) Malignant tumours are a mass of proliferating cells called neoplastic or tumour cells.
These cells grow very rapidly,invading and damaging the surrounding normal tissues.
Unlike benign tumours,malignant tumours do not remain confined to their original site and can spread to other parts of the body through a process called metastasis.

(A) metastasis.
In malignant tumours,the cells divide rapidly and move to distant parts of the body through blood or lymph to form new tumours at secondary sites. This unique and dangerous property of malignant tumours is known as metastasis.

(B) The correct answer is $B$.
Cancer cells lose the property of contact inhibition.
Contact inhibition is a mechanism that prevents normal cells from dividing when they come into contact with other cells.
Cancer cells ignore these signals and continue to divide uncontrollably,leading to the formation of a tumor.
Therefore,the statement that they exhibit contact inhibition is incorrect.