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:
D. N
Explanation:
Meiosis is a kind of cell division which produces daughter cells that are genetically different from the parent cell and have a reduced number of chromosomes (by half).
Meiosis occurs only in reproductive cells to produce gametes. If a diploid (2n) cell undergoes meiosis, a haploid (n) daughter cell will result. This means that the chromosome number has been reduced by half in order to maintain the chromosomal number of the next generation.
Answer:
Law
Explanation:
The human instincts are a product of natural biological phenomenons which define and construct human behaviors. The standardized rules and norms of the society are formed by the society and is generally very open for interpretation.
People learn from looking at other people and adapt to the most common social behaviors. That is how they adhere to the standardized norms and rules of the society.
Therefore laws help in standardization
I hope the answer is helpful.
Thanks.
Answer:
A
Explanation:
As the species seperated they formed a differnt beak based on what they ate.
The answers is A). Plantas
