According to slide 12, what is the relationship between opportunistic infections and the number of T cells a person has? Explain with science from the lecture given.

The fewer number of T cells a person has, the more chances to be affected by an opportunistic infection. When the number of T cells reaches 200 cells/µl, the person is at risk of being infected by other infections.  

Explanation:

The whole immune system of a person who is infected with HIV infection seems to be severely affected.  When the person is not treated or the disease is in a very advanced stage, the depletion of the T- cells turns to be very sharped, especially CD4+ T cells. At this point, the immune system can not resist the attack of other microorganisms. The lower is the number of CD4+ T Cells, the higher possibility the person has to be attacked by opportunistic infections.

Classically, it has been suggested that opportunistic infections appear after the CD4 + T lymphocytes reach very low levels, such as 200 cells/µl. The number of circulating T cells can be used as an indicator and a measure of global "immune competence", and the previously mentioned amount of CD4 + T cells is an accepted universal reference used to predict the risk of having one of these opportunistic infections.

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation:

i think the answer would be d