Cancer Questions in English

(D) Leukemia is a type of cancer that affects the blood and bone marrow.
It is characterized by the abnormal and uncontrolled production of white blood cells (leukocytes) in the body.
These abnormal cells crowd out healthy blood cells,leading to symptoms like anemia,frequent infections,and bleeding.
Therefore,it is commonly referred to as blood cancer.

(C) Retroviruses are a group of viruses that have the ability to transform normal cells into cancerous cells in animals. They contain an enzyme called reverse transcriptase,which allows them to integrate their genetic material into the host cell's genome. This integration can disrupt normal cell cycle regulation,leading to uncontrolled cell division and cancer.

(A) Retroviruses are a group of viruses that contain $RNA$ as their genetic material.
During their life cycle,they use an enzyme called reverse transcriptase ($RNA$-dependent $DNA$ polymerase) to convert their $RNA$ genome into $DNA$ inside the host cell.
This newly synthesized $DNA$ is then integrated into the host genome.
Therefore,the statement that '$DNA$ is not present at any stage of the retrovirus life cycle' is false,as $DNA$ is a crucial intermediate in their replication process.

(C) Retroviruses are known to cause cancer in humans and animals.
These viruses possess viral oncogenes,denoted as $v$-oncogenes,in their genome.
When these viruses infect a host cell,the $v$-oncogenes can transform normal cells into cancerous cells by disrupting the regulation of the cell cycle.
Therefore,the presence of $v$-oncogenes is the primary reason for their oncogenic potential.

(A) Cancer cells are characterized by uncontrolled and rapid cell division. Radiation therapy works by damaging the $DNA$ of cells. Because cancer cells are actively dividing and lack the efficient $DNA$ repair mechanisms found in normal,healthy cells,they are significantly more susceptible to radiation-induced damage. Therefore,the rapid rate of cell division makes them the primary target for radiation therapy.

(D) Carcinoma is a type of cancer that starts in cells that make up the skin or the tissue lining organs,such as the liver or kidneys. These are known as epithelial cells.
Since carcinoma originates from epithelial tissue,it is classified as a malignant tumor of the skin or mucous membrane.
In contrast,sarcomas are cancers that arise from connective tissues (like bone,cartilage,fat,muscle,or blood vessels).
Therefore,the correct option is $D$.

(D) $1$. $A$ is incorrect: Cannabinoids are known for their effects on the cardiovascular system and are generally abused; they are not standard painkillers for post-surgery patients.
$2$. $B$ is incorrect: Benign tumors remain confined to their original location and do not spread to other parts of the body (they do not show metastasis).
$3$. $C$ is incorrect: Heroin is a depressant that slows down body functions.
$4$. $D$ is correct: Malignant tumors are cancerous growths that exhibit the property of metastasis,meaning they spread to distant sites in the body through blood or lymph.

(D) Cancer cells are characterized by the loss of $contact$ inhibition.
Normal cells show a property called $contact$ inhibition by virtue of which contact with other cells inhibits their uncontrolled growth.
Cancer cells appear to have lost this property.
As a result, they continue to divide, giving rise to masses of cells called tumors.
They also compete with normal cells for vital nutrients and can spread to distant sites (metastasis), which is not a property of normal cells.

(C) Cancer cells are characterized by uncontrolled cell division. Mutations play a critical role in this process by activating proto-oncogenes (which stimulate the cell cycle) and inactivating tumor suppressor genes (which control the cell cycle). Furthermore,cancer cells often exhibit unlimited replicative potential due to the activation of the enzyme telomerase,which maintains telomere length. Therefore,mutation does not inhibit the production of telomerase; rather,it often leads to its overexpression or activation to ensure the immortality of the cancer cell. Thus,option $C$ is incorrect.

(A) Oncoviruses are cancer-causing viruses that can be either $DNA$ or $RNA$ viruses.
Examples include the Epstein-Barr virus,Hepatitis $B$ virus,and Human Papillomavirus.
These viruses contain oncogenes or stimulate the host cell's genes to promote uncontrolled cell division,leading to the development of cancerous tumors.
Therefore,the Epstein-Barr virus is classified as an oncovirus because it promotes the growth of cancer.

(A) Cancer cells exhibit uncontrolled cell division and lack contact inhibition,making them virtually immortal as long as they receive nutrients from the host body. This uncontrolled proliferation is primarily caused by mutations in genes that regulate the cell cycle,such as proto-oncogenes and tumor suppressor genes. Therefore,the Reason correctly explains why cancer cells continue to divide indefinitely (immortality).

(N/A)

Normal cell	Cancerous cell
$1$. Normal cells show the property of contact inhibition. Therefore,when these cells come into contact with other cells,they stop dividing.	$1$. Cancerous cells lack the property of contact inhibition. Therefore,they continue to divide,thereby forming a mass of cells or tumor.
$2$. They undergo differentiation after attaining a specific growth.	$2$. They do not undergo differentiation.
$3$. These cells remain confined at a particular location.	$3$. These cells do not remain confined at a particular location. They move into neighboring tissues and disturb their function.

(N/A) Metastasis is a characteristic property of malignant tumors. It is the pathological process by which cancerous cells spread from the primary site to other parts of the body. In this process,some cells from the tumor get detached and enter the bloodstream or lymphatic system. Through these circulatory systems,the cells reach distant organs,where they settle and divide uncontrollably to initiate the formation of new tumors,a process known as secondary tumor formation.

(A) Cancer is one of the most dreaded diseases of human beings and is a major cause of death all over the globe. More than a million Indians suffer from cancer and a large number of them die from it annually. The mechanisms that cause transformation of normal cells into cancerous neoplastic cells,treatment,and control of cancer are some of the most intense areas of research in biology and medicine.
In our body,cell growth and differentiation is highly controlled and regulated. Cancer cells lose this property of control. Normal cells show a property called $contact$ $inhibition$ by virtue of which contact with other cells inhibits their uncontrolled growth. Cancer cells appear to lose this property. As a result,cancerous cells just continue to divide giving rise to masses of cells called $tumors$.
$Tumors$ are of two types: $benign$ and $malignant$. $Benign$ $tumors$ normally remain confined to their original location and do not spread to other parts of the body and cause little damage. $Malignant$ $tumors$ are a mass of proliferating cells called $neoplastic$ or $tumor$ $cells$. These cells grow very rapidly,invading and damaging the surrounding normal tissues. As these cells actively divide and grow,they also starve the normal cells by competing for vital nutrients. Cells sloughed from such tumors reach distant sites through blood,and wherever they get lodged in the body,they start a new tumor there. This property called $metastasis$ is the most feared property of malignant tumors.
$Causes$ $of$ $Cancer$: Transformation of normal cells into cancerous neoplastic cells may be induced by physical,chemical,or biological agents. These agents are called $carcinogens$.
Ionizing radiations like $X-rays$ and $gamma$ $rays$ and non-ionizing radiations like $UV$ cause $DNA$ damage leading to neoplastic transformation. The chemical carcinogens present in tobacco smoke have been identified as a major cause of lung cancer. Cancer-causing viruses called $oncogenic$ $viruses$ have genes called $viral$ $oncogenes$.
Furthermore,several genes called $cellular$ $oncogenes$ $(c-onc)$ or $proto-oncogenes$ have been identified in normal cells which,when activated under certain conditions,could lead to oncogenic transformation of the cells.
$Cancer$ $detection$ $and$ $diagnosis$: Early detection of cancers is essential as it allows the disease to be treated successfully in many cases. Cancer detection is based on biopsy and histopathological studies of the tissue and blood and bone marrow tests for increased cell counts in the case of leukemias.
In biopsy,a piece of the suspected tissue cut into thin sections is stained and examined under a microscope (histopathological studies) by a pathologist. Techniques like radiography $(X-rays)$,$CT$ ($computed$ $tomography$),and $MRI$ ($magnetic$ $resonance$ $imaging$) are very useful to detect cancers of the internal organs.
$CT$ uses $X-rays$ to generate a three-dimensional image of the internals of an object. $MRI$ uses strong magnetic fields and non-ionizing radiations to accurately detect pathological and physiological changes in the living tissue.
Antibodies against cancer-specific antigens are also used for certain cancers. Techniques of molecular biology can be used to detect genes in individuals with inherited susceptibility to certain cancers. Identification of such genes,which predispose an individual to certain cancers,may be very helpful in prevention of cancers. Such individuals may be advised to avoid exposure to particular carcinogens to which they are susceptible (e.g.,tobacco smoke in case of lung cancer).
$Treatment$ $of$ $Cancer$: The common approaches for treatment of cancer are surgery,radiation therapy,and immunotherapy. In radiotherapy,tumor cells are irradiated lethally,taking proper care of the normal tissues surrounding the tumor mass. Several chemotherapeutic drugs are used to kill cancerous cells.
Some of these are specific for particular tumors. Majority of drugs have side effects like hair loss,anemia,etc. Most cancers are treated by combination of surgery,radiotherapy,and chemotherapy. Tumor cells have been shown to avoid detection and destruction by immune system. Therefore,the patients are given substances called biological response modifiers such as $\alpha-interferon$ which activates their immune system and helps in destroying the tumor.

(N/A)

Malignant tumor	Benign tumor
$(1)$ It is a cancerous tumor.	$(1)$ It is a non-cancerous tumor.
$(2)$ Cells are not adhered to each other.	$(2)$ Cells are adhered to each other.
$(3)$ Cells tend to move into the bloodstream.	$(3)$ Cells remain intact within the cell mass.
$(4)$ The tumor shows metastasis and thus invades different body parts.	$(4)$ The tumor does not show metastasis and other body parts are not affected.
$(5)$ The cells show indefinite growth.	$(5)$ Cells stop growth after attaining a certain size.
$(6)$ Malignant tumors are more fatal to the body.	$(6)$ Benign tumors are less fatal to the body.

(N/A) The pathological condition characterized by uncontrolled cell division is known as cancer.
In normal cells,cell division is strictly regulated by various checkpoints and signaling pathways.
When these regulatory mechanisms fail,cells begin to divide uncontrollably,leading to the formation of a mass of cells known as a tumor or neoplasm.
This uncontrolled proliferation disrupts the normal structure and function of the affected organ or tissue.

(N/A)

Normal cell	Cancerous cell
$(1)$ They show contact inhibition.	$(1)$ They lose the property of contact inhibition.
$(2)$ Cell division is strictly regulated.	$(2)$ Cell division is uncontrolled and unregulated.
$(3)$ They undergo differentiation after attaining a specific growth.	$(3)$ They do not undergo differentiation and remain in a proliferative state.
$(4)$ Cells remain confined to their specific location.	$(4)$ Cells can metastasize (transported to other locations) and cause damage to other body tissues.

(B) Malignant tumors are masses of proliferating cells called neoplastic or tumor cells. These cells grow very rapidly,invading and damaging the surrounding normal tissues. As these cells divide actively,they compete with normal cells for vital nutrients,effectively starving them. Cells shed from such tumors reach distant sites through the blood,and wherever they get lodged in the body,they start a new tumor. This property of metastasis is the most feared property of malignant tumors because it makes the cancer spread throughout the body.

(N/A) Metastasis: The property of malignant tumors where cells slough off from the tumor and reach distant sites through the blood to form new tumors elsewhere is called metastasis. This is the most feared property of malignant tumors.
Viral Oncogenes: Cancer-causing viruses are called oncogenic viruses,and their genes are known as viral oncogenes. In normal cells,these genes are present as proto-oncogenes,which,upon activation under certain conditions,lead to oncogenic transformation of the cells.

(N/A) Cancer is defined as the abnormal and uncontrolled division of cells.
The differences between cancer cells and normal cells are as follows:

Cancer Cells	Normal Cells
$(1)$ Cancer cells divide in an uncontrolled manner.	$(1)$ Normal cells divide in a controlled manner.
$(2)$ These cells do not show contact inhibition.	$(2)$ These cells show contact inhibition.
$(3)$ Life span is indefinite.	$(3)$ Life span is definite.

- In our body,the growth and differentiation of cells are highly controlled and regulated.
- Normal cells exhibit a property called contact inhibition,where contact with other cells inhibits their uncontrolled growth and division.
- Cancerous cells lose this property of contact inhibition,leading to continuous,uncontrolled division,which results in masses of cells known as tumors.
- The transformation of normal cells into cancerous cells is induced by physical,chemical,or biological agents known as carcinogens.

(N/A) Cancer detection and diagnosis: Early detection is essential for successful treatment. Detection is based on biopsy and histopathological studies of tissues,and blood and bone marrow tests for increased cell counts in leukemias. In a biopsy,a piece of suspected tissue is cut into thin sections,stained,and examined under a microscope by a pathologist.
Techniques like radiography ($X$-rays),$CT$ (computed tomography),and $MRI$ (magnetic resonance imaging) are useful for detecting internal organ cancers. $CT$ uses $X$-rays to generate a three-dimensional image of internal structures. $MRI$ uses strong magnetic fields and non-ionizing radiations to detect pathological and physiological changes in living tissues.
Antibodies against cancer-specific antigens are also used. Molecular biology techniques help detect genes in individuals with inherited susceptibility. Identifying such genes helps in cancer prevention by advising individuals to avoid specific carcinogens (e.g.,tobacco smoke for lung cancer).
Treatment of cancer: Common approaches include surgery,radiation therapy,and immunotherapy. In radiotherapy,tumor cells are irradiated lethally while protecting surrounding normal tissues.
Chemotherapeutic drugs are used to kill cancer cells,though many have side effects like hair loss and anemia. Most cancers are treated using a combination of surgery,radiotherapy,and chemotherapy. Since tumor cells often evade the immune system,patients are given biological response modifiers like $\alpha$-interferon,which activate the immune system to destroy the tumor.

(N/A) Carcinogen: Any agent,chemical,physical,or biological,that causes cancer is known as a carcinogen. Examples include $UV$ radiation,tobacco smoke,and certain viruses.
Tumour: $A$ tumour is a mass of unorganized cells formed due to the uncontrolled and abnormal division of cells in the body.

(B) Chromosomal aberrations are commonly observed in cancer cells. Cancer is characterized by uncontrolled cell division,which is often associated with significant changes in the structure or number of chromosomes (chromosomal aberrations) within the affected cells. $AIDS$ is a viral disease,while recombination and crossing over are normal biological processes occurring during meiosis.

(B) $1$. $AIDS$ (Acquired Immuno Deficiency Syndrome) is an infectious disease caused by the Human Immunodeficiency Virus $(HIV)$.
$2$. Cancer is a non-infectious disease characterized by uncontrolled cell division, which can lead to death if not treated.
$3$. Typhoid is an infectious disease caused by the bacterium $Salmonella \text{ } typhi$.
$4$. Therefore, among the given options, only cancer is a non-infectious disease that can cause death.

(A) Infectious diseases are those that are easily transmitted from one person to another.
$AIDS$ is an infectious disease caused by the $HIV$ virus.
$Cancer$ is a non-infectious disease caused by uncontrolled cell division and is not transmitted from one person to another.
$Pneumonia$ and $Common \text{ } cold$ are infectious diseases.
Since $Cancer$ is non-infectious, the group containing $Cancer$ cannot be classified as purely infectious diseases.

(A) In normal cells,growth and differentiation are highly controlled and regulated. Normal cells show a property called $Contact \ Inhibition$ by virtue of which contact with other cells inhibits their uncontrolled growth. Cancer cells appear to have lost this property. As a result of the loss of $Contact \ Inhibition$,cancerous cells continue to divide,giving rise to masses of cells called tumors.

(C) Carcinogens are agents that cause cancer. These can be physical,chemical,or biological.
Physical carcinogens include ionizing radiations (like $X$-rays and $\gamma$-rays) and non-ionizing radiations (like $UV$ rays).
$X$-rays and $\gamma$-rays are ionizing radiations because they have enough energy to remove electrons from atoms.
$UV$ rays are non-ionizing radiations that cause $DNA$ damage,leading to neoplastic transformation.
Therefore,$UV$ rays are the correct example of non-ionizing radiation among the given options.

(B) Tumors are generally classified into two types: $Benign$ and $Malignant$.
$Benign$ tumors normally remain confined to their original location and do not spread to other parts of the body.
$Malignant$ tumors are composed of mass of proliferating cells called neoplastic or tumor cells.
These cells grow very rapidly,invading and damaging the surrounding normal tissues.
As these cells are active,they reach distant sites through the blood,and wherever they get lodged in the body,they start a new tumor there.
This property of spreading to distant sites is called metastasis,which is the most feared property of $Malignant$ tumors.

(C) Cancer is classified based on the tissue of origin.
$1$. Carcinoma: Cancer arising from epithelial tissues (e.g.,skin,lining of organs). Melanoma is a cancer of melanocytes,which are epithelial-derived cells in the skin.
$2$. Sarcoma: Cancer arising from connective tissues (e.g.,bone,cartilage,fat).
$3$. Leukemia: Cancer of blood-forming tissues (e.g.,bone marrow).
$4$. Lymphoma: Cancer of the lymphatic system.
Since melanoma originates from the skin (epithelial tissue),it is classified as a carcinoma.

(B) Cancer is classified based on the tissue of origin.
$1$. Carcinoma: Cancer originating from epithelial tissues (e.g.,skin,lining of organs).
$2$. Sarcoma: Cancer originating from mesodermal tissues (e.g.,bone,cartilage,muscle,fat,connective tissue).
$3$. Leukemia: Cancer of blood-forming tissues (e.g.,bone marrow) leading to an abnormal increase in white blood cells.
Since the question specifies cancer originating in mesodermal tissue,the correct classification is Sarcoma.

(A) Carcinogens are agents that cause cancer by inducing mutations in the $DNA$ of cells.
$UV$ radiation (physical agent),vehicle exhaust fumes (chemical agent),and cigarette smoke (chemical agent) are all well-known carcinogens.
Pollen grains with dust particles are generally considered allergens that trigger immune responses like asthma or hay fever,but they are not classified as carcinogens.

(C) Globally,breast cancer is the most frequently diagnosed cancer among women. According to the World Health Organization $(WHO)$ and global cancer statistics,it accounts for the highest incidence rate of all cancers in the female population worldwide.

(B) Cancer is caused by the uncontrolled division of cells. This process is regulated by two main types of genes: proto-oncogenes (which promote cell growth) and tumor suppressor genes (which inhibit cell division).
In cancer cells,proto-oncogenes often mutate into oncogenes,leading to excessive cell growth.
Simultaneously,tumor suppressor genes (such as $p53$ or $Rb$) are inactivated or deleted,which removes the 'brakes' on the cell cycle,allowing the cells to divide uncontrollably.
Therefore,the inactivation of tumor suppressor genes is a critical step in the development of cancer.

(A) Proto-oncogenes are normal genes present in the cells of higher organisms that regulate cell growth and division.
When these genes are activated or mutated by certain physical,chemical,or biological agents (carcinogens),they are transformed into cancer-causing genes known as oncogenes.
Specifically,the cellular oncogenes are referred to as $c-onc$ (or proto-oncogenes),and when they are activated to cause cancer,they are often referred to as oncogenes. In the context of viral transformation,the viral oncogenes are called $v-onc$. However,the general term for the transformed cancer-causing gene derived from a proto-oncogene is an oncogene. Given the options,$c-onc$ represents the cellular proto-oncogene,and the transformation leads to an active oncogene state.

(A) Fine Needle Aspiration Cytology $(FNAC)$ is a diagnostic procedure used to investigate lumps or masses. In this technique,a thin,hollow needle is inserted into the mass to extract cells or fluid for microscopic examination. It is commonly used for the diagnosis of breast cancer. $C.T.$ scans and $M.R.I.$ are imaging techniques used for visualization,while a Pap smear is specifically used for cervical cancer screening.

(A) The $Pap \, smear$ (Papanicolaou test) is a screening procedure used to detect potentially precancerous and cancerous processes in the cervix.
While biopsy is used to confirm a diagnosis,the $Pap \, smear$ is the primary screening method used for early detection of cervical cancer.
Therefore,$Pap \, smear$ is the most appropriate answer in the context of primary diagnostic screening.

(A) In the treatment of cancer,biological response modifiers such as $\alpha$-interferons are used. These substances activate the patient's immune system and help in destroying the tumor. Therefore,the administration of $\alpha$-interferons leads to the activation of the immune system.

(D) Cancer treatment involves a multidisciplinary approach to eliminate or control malignant cells.
$1$. Radiotherapy: Uses high-energy radiation to kill cancer cells or shrink tumors.
$2$. Surgery: Involves the physical removal of the tumor or cancerous tissue.
$3$. Chemotherapy: Uses specific drugs to destroy rapidly dividing cancer cells throughout the body.
Since all these methods are standard practices in oncology,the correct answer is $D$.

(D) Anti-cancer drugs,also known as chemotherapeutic agents,primarily target rapidly dividing cells.
They function by interfering with the cell cycle,often by inhibiting $DNA$ synthesis or replication,which prevents the cancer cells from proliferating.
By arresting the cell cycle at specific checkpoints,these drugs effectively stop the uncontrolled growth of tumors.
Therefore,both inhibiting $DNA$ synthesis and arresting the cell cycle are primary mechanisms of action for these drugs.

(C) Alpha-fetoprotein $(AFP)$ is a protein normally produced by the fetal liver and yolk sac during development.
In adults,elevated levels of $AFP$ in the blood are often used as a tumor marker.
It is most commonly associated with hepatocellular carcinoma (liver cancer) and certain germ cell tumors.
Therefore,$AFP$ is a diagnostic marker for liver cancer.

(A) Cancer treatment involves various methods such as surgery,radiotherapy,chemotherapy,and immunotherapy.
In radiotherapy,ionizing radiation (such as $X$-rays,gamma rays,or radioactive isotopes like Cobalt-$60$ or Iodine-$131$) is used to kill cancer cells or shrink tumors by damaging their $DNA$.
Therefore,Cobalt therapy and Iodine therapy are specific types of radiotherapy.

(A) Metastasis is the defining characteristic of malignant tumors.
It refers to the process where cancer cells break away from the primary site of origin,travel through the blood or lymphatic system,and invade other parts of the body to form secondary tumors.
This property makes malignant tumors much more dangerous than benign tumors,which remain localized at their site of origin.

(B) Biopsy is a medical procedure that involves taking a small sample of tissue from the body to examine it under a microscope.
It is primarily used to detect the presence of malignant cells,which is the hallmark of $Cancer$.
In this process,a piece of the suspected tissue is cut into thin sections,stained,and examined by a pathologist to determine if the cells are cancerous or benign.

(B) $Glioma$ is a type of tumor that occurs in the brain and spinal cord. It arises from glial cells. In the classification of cancers based on the tissue of origin,$Glioma$ is technically a type of sarcoma because it originates from tissues derived from the embryonic mesoderm or neuroectoderm (specifically,glial cells are supporting cells of the nervous system). However,it is often categorized separately in clinical oncology. Given the standard options provided in many biology textbooks,$Glioma$ is classified under the category of sarcomas (cancers of connective tissue or supporting tissues).

(D) $Kaposi \, Sarcoma$ is a cancer that develops from the cells that line lymph or blood vessels. It typically appears as tumors on the skin or on mucosal surfaces such as inside the mouth,but tumors can also develop in other parts of the body,such as in the lymph nodes,lungs,or digestive tract. Therefore,it is considered a cancer of both soft tissues and the lymphatic system.

(D) Radiation therapy and exposure primarily target cells that are rapidly dividing.
Among the given options,the bone marrow contains hematopoietic stem cells which undergo continuous and rapid cell division to produce blood cells.
Because these cells are highly proliferative,they are the most sensitive to ionizing radiation,leading to a decrease in blood cell production (myelosuppression).
Therefore,the bone marrow is the most affected part.

(B) Cancer is defined as the uncontrolled division of cells,which leads to the formation of a mass of cells known as a tumor.
Tumors are classified into two types: $Benign$ and $Malignant$.
$Benign$ tumors remain confined to their original location and do not spread to other parts of the body.
$Malignant$ tumors are cancerous; they invade surrounding tissues and can spread to distant sites through blood or lymph,a process known as $Metastasis$.
$Osteosarcoma$ is a type of bone cancer,which is a $Malignant$ tumor.

(C) The correct statement is that oncogenes are absent in normal cells.
$1$. Adolescence is generally defined as the period between $12$ to $18$ or $19$ years,not $20$.
$2$. The $HIV$ envelope contains glycoproteins like $gp120$ and $gp41$,while $p24$ and $p17$ are capsid and matrix proteins,respectively.
$3$. Oncogenes (or proto-oncogenes) are present in normal cells in an inactive form; when mutated or overexpressed,they become oncogenes that cause cancer. However,in the context of typical biology MCQs,the statement 'absent in normal cells' is often used to refer to the active oncogenic form.
$4$. Cancer is a disease that requires early detection and treatment; negligence often leads to advanced stages and death.

(D) $1$. $Sarcoma$ is a type of cancer that arises from tissues of mesodermal origin, such as bones, muscles, and connective tissues.
$2$. $Melanoma$ is a type of cancer that develops from melanocytes, which are pigment-producing cells found in the skin.
$3$. $Lymphosarcoma$ is a cancer that originates in the lymphatic system.
$4$. The option $D$ states that cartilage rarely develops cancer. While cartilage is a connective tissue, it is not a specific type of cancer name like the others. The other three options describe specific types of cancers, whereas $D$ describes a tissue type and a general observation, making it the mismatched pair in the context of classifying cancer types.