Light dependent reaction take place on the thylakoid membranes.
Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from the parent(s). Asexual reproduction produces new individuals without the fusion of gametes, genetically indentical to the parent plants and each other, when mutations occur
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>
Answer:
A. the cell membrane protects the cell
Some isotopes are radioactive, which makes them suitable for medical imaging procedures. Radioactive isotopes have found a wide range of use in medicine. For example, they are used as tracers for diagnostic as well as research on metabolic processes. They are also used in medical imaging procedures, these isotopes include fluorine-18, gallium-67 among many others.