Abstract The immune system is an essential body system that enables the organisms to launch attacks against the pathogens. The immune system comprises two types of defenses: adaptive and innate. The innate immune system consists of physical barriers like skin, chemicals in the blood. This type of immunity system is non-specific. This means it can attack any type of pathogen whether it is a virus or bacteria. The adaptive immune system, on the other hand, can provide advanced protection from pathogens that can cause harm to the body. The adaptive immune system has its further division which indicates the difference in the adopted methods of response. These differences between the humoral and the cell-mediated response are delineated through this review paper. There are markers on the T and B lymphocyte cells known as the MHC-class markers, that are crucial to distinguish between self and foreign cells. With these markers, the immune system can launch a response against the inva...
Recently, there have been a lot of speculations about stem cells and their ethicality. The main question is: “Is it ethical to kill an embryo in order to procure stem cells where that embryo has a potential to grow into a human being?” To answer this question we first need to understand what are stem cells? What benefits do they provide us with? What are some disadvantages associated? Can they be used to treat a person who has been diagnosed with a terminal illness like cancer or an organ failure? So let us begin with some basics. Stem cells are pluripotent cells, that is, they have an ability to develop into an organism. A zygote, product of a sperm and an ovum fusion, is a classic example of an undifferentiated stem cell. A zygote is a single undifferentiated cell which divides itself to form an embryo. The undifferentiated cells found in an embryo are called the Embryonic stem cells. As the embryo enters its eighth week it is called as a fetus. Here, the stem cells begin...