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:
1. "a, O, and J"
2. "R and C"
3. I'm not entirely sure about #3, but I believe the answer is "d and R"
4."J, K, I, M, N"
5. "d"
6. "I" explain why: "It is at the bottom, so it is therefore the oldest."
7. "Q" explain why: "It is at the top, so it is therefore the youngest."
8. The folding occured before the faulting. Why? Because the folding is evident in the second half of the fault.
<u><em>DISCLAIMER: any of these answers could be wrong. I did my best but I am still human.</em></u>
Answer:
Extension
Explanation:
Polymerase chain reaction is given by Kary Mullis and it contains three steps denaturation, annealing, and extension. In denaturation, the temperature is raised to 96° c so that the DNA can denature.
In annealing, the temperature gets reduced to 55°c so that the primer can bind to the complementary sequence. In extension, Taq polymerase is used to extend the new strand.
This enzyme is isolated from thermophilic bacteria and the temperature here is raised to 72°c so that the enzyme can extend the primer and make the complementary strand. So the right answer is extension.
It is speeding up because more distance is covered every second.
Explanation:
The car can be described to be speeding up because more distance is covered every second.
From what we understand about velocity and acceleration, the car is accelerating through the ramp.
It's velocity is increasing with every second it covers.
This will invariable reduce the time between each distance covered.
Originally, the toy car starts with a low initial velocity or speed. As it gains acceleration, the speed will increase and more distance covered per seconds.
This is why the dots clustered towards the end of the diagram. The positions are getting closer and distance reducing per seconds.
Learn more:
Speed brainly.com/question/1548911
#learnwithBrainly
Answer:
G - 21%
T - 29%
A - 29%
Explanation:
Nucleotide bases in DNA are complementary. Adenosine (A) binds to Thymine (T) while Cytosine (C) binds to Guanine (G). Hence the composition of A in DNA is the same as that of T; and that of C is the same as that of G.
From the information given, C is 21%
Therefore G is also 21% of the genome as C is bound to G, the therefore are the same proportion.
C and G make up 42% of the genome (that 21% + 21%).
The remaining 58% (100%-42%) is made up of A + T
Similarly the proportion of A is equal to that of T,
Hence A is 29% (half of 58%) and T is 29%.
