Question

In malignant tumors, the cells proliferate, grow rapidly and move to other parts of the body to form new tumors. This property of cancer cells is called _____________ .

• A. metastasis
• B. metagenesis
• C. karyokinesis
• D. teratogenesis

Answer 1

The correct option is A metastasis

Cancer is a disease where cells start divide uncontrollably and invade the surrounding healthy tissues. This is due to alterations or changes in the genetic material. The abnormal, uncontrolled division leads to the formation of a mass of cells called tumors.

Tumors are of two types - benign (non-cancerous) and malignant (cancerous) tumor.

• Benign tumors - These tumors are localized at a particular location in the body and do not spread to the other parts of the body. Such tumors are generally harmless.
• Malignant Tumor - These tumors are cancerous meaning that it divides rapidly and has a characteristic feature of spreading to the other normal tissues of the body.

Metastasis is a characteristic property of malignant tumors, it is also the major point of difference between benign and malignant tumors. The spread of cancer cells begins from the site of origin to the other areas of the body via bloodstream and lymph leading to the formation of numerous tumors in other parts of the body. This spread from the primary site of origin of the disease to the secondary site is referred to as metastasis. The metastatic cells multiply rapidly and damage the normal/healthy cells surrounding them.

Figure : Cancer cells showing metastasis

Whereas, metagenesis is a pattern of living style, where one generation is produced asexually and the next one is produced sexually. This is otherwise called as alternation of generations. For example, polyp and medusa are two body forms of coelenterates, polyp produce medusae asexually and medusae from polyp sexually.

Figure : Metagenesis

Teratogenesis is a prenatal toxicity condition mainly characterised by structural, functional defects in the developing embryo or foetus.

Figure : Structural deformity (Teratogenesis)

The cell cycle exhibits the division of the parent cell into daughter cells in a sequentially coordinated manner. The steps involved are interphase (the portion of the cell cycle that is not accompanied by gross changes under the microscope, and includes the G1, S and G2 phases), karyokinesis (division of nucleus) and cytokinesis (division of cytokinesis)