Human Health and Disease Test - 7

Retrovirus, any of a group of viruses that belong to the family Retroviridae and that characteristically carry their genetic blueprint in the form of ribonucleic acid (RNA). Retroviruses are named for an enzyme known as reverse transcriptase, which was discovered independently in 1971 by American virologists Howard Temin and David Baltimore.

HIV virus belongs to this group as its genetic material is also RNA.

World AIDS Day, designated on 1 December every year since 1988, is dedicated to raising awareness of the AIDS pandemic caused by the spread of HIV infection, and mourning those who have died of the disease.

A tumor enclosed within a capsule is called benign tumor. Benign tumors normally remain confined to their original location and do not spread to other parts of the body and cause little damage.

AIDS can be transmitted from infected person to healthy person through blood transfusion. The most common way of transmission of AIDS is during sexual intercourse with multiple partners without protection.

A metastatic cancerous tissue is called sarcoma if the disorder is in fibroblast. The property of cancerous cells to reach from one part of the body to other through blood is called metastasis.

Carcinoma is a type of cancer or Malignant tumors of the skin or mucous membrane that starts in cells that make up the skin or the tissue lining organs, such as the liver or kidneys.

The physical, chemical or biological agents that convert normal cell into cancerous cell are called carcinogens.

Cancer cells are killed by radiation to treat cancer. Cancer cells are undergoing rapid division and radiation killed these cells but normal cells are not affected by these radiation therapy.

AIDS is caused by human immune virus (HIV). HIV infects and kills B-lymphocytes. In this disease viral RNA genome is converted into DNA copy by reverse transcriptase.

Lymphadenopathy-associated virus (LAV) A former name for HIV is the virus that causes AIDS. It is membrane of lymph nodes. Lymph node get affected and destroy the defense mechanism of human body.

Radiation therapy targets the DNA inside the cell by making them unable to divide and reproduce. Cancer cells perform unlimited cell division. Now, when their dividing ability is targeted, naturally they respond more. Newly formed cells can be easily destroyed by radiation of high frequency. They stop dividing. Thus, the tumour shrinks. 

However, the adjoining normal cells also get affected by radiation but they can repair themselves more effectively.