All the cells in a person's body have the same DNA and the same genes. However, the difference between cells in different tissues and organs is that the "expression" of the genes differs between cells. Expression means that the message from the DNA is being copied and made into protein.
Macronutrients can be defined as the compounds which can be found in large quantities in the human diet. Majority of the energy for the functioning of the body is derived from these macronutrients. These includes the fats, carbohydrates, and the proteins.
Micronutrients can be defined as the compounds which are required by the body in small quantities, but they are essential for the proper growth of the body. These includes the vitamins and minerals.
Hence, the given food and the nutrient groups can be matched as follows:
Macronutrients - Carbohydrates, proteins, fats.
Micronutrients - Zinc, calcium.
The human immunodeficiency virus (HIV) that causes the disease known as aids selectively infects helper T cells (CD4+).
This retrovirus also infects macrophages and dendritic cells. When CD4+ T cell numbers decrease below a critical level (due to the killing of this cells with different mechanisms), cell-mediated immunity is lost. As a result, the body becomes progressively more susceptible to infections, leading to the development of AIDS.
<span> HIV can be transmitted only via body fluids like blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk, which means that people usually get or transmit HIV through sexual behaviours and use of the needle. For HIV infection, these fluids must come in direct contact with a mucous membrane or damaged tissue. Another way is to be directly injected into the bloodstream (from a needle for example).</span>
