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>
The eubacteria is photosynthetic, like a plant is.
Answer:1)Temperature 2)Wind 3)Humidity 4)Light:plants tend to transpire more rapidly in light than in the dark.
Explanation:
Answer:
It will decrease in size and it will pinch to surround anything entering the cell.
Answer:
The options are
A. Delta
B. Watershed
C. River
D. Lake
The CORRECT ANSWER IS A
A. Delta
Explanation:
Delta fan is a low lying vegetation that consists majorly of stream –the river accumulates borne sediments at its mouth. It occurs when a river flows to a body of standing water, taking with it soil and minerals as it flows into the body of standing water to form a fan shape or triangle as seen in the attached image.
