Final answer:
HIV is primarily transmitted through unprotected sexual contact, blood, and perinatal transmission. Antiretroviral therapy is a treatment option for HIV, but it is not a cure. HIV weakens the immune system by targeting helper T cells.
Step-by-step explanation:
HIV, which stands for Human Immunodeficiency Virus, is primarily transmitted through unprotected sexual contact, blood, and perinatal transmission. It is not transmitted through casual contact. HIV weakens the immune system by targeting helper T cells, not red blood cells. Although there is no cure for HIV, antiretroviral therapy can help manage the virus and improve the quality of life for individuals living with HIV.