Answer: light is a eletromagnetic wave, no it does not need a medium
Explanation:
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Answer:
1. Using the graph, describe the events that occur in the body during the first year of
HIV infection.
2. Describe what happens between the first year and the tenth year of infection.
3. Explain why the concentration of antibodies begins to decrease after nine years of
infection.
4. At what point on the graph does an infected person have AIDS?
5. Why does the number of HIV particles begin to level off after nine years?
6. How do you think the high rates of HIV transmission in humans might be related to the length of time it takes for the virus to develop into AIDS?
Answer: Antigens
Explanation: The ABO system of blood grouping is based on the basis of the type of antigens that are present in the red blood cells. Erythrocytes is another name for the red blood cells. Antigens are molecules that are capable of eliciting immune response. There are two types of antigens: antigen A and B. Blood type A has only antigen A, blood type B has only antigen B, blood type AB has both antigen A and B while blood type O has no antigen (neither A nor B antigen).
Similarly, Rh trait is determined by the presence or absence of rhesus antigen in the erythrocytes. Rhesus antigen is an antigen first discovered in rhesus monkey. Rh+ indicates the presence of rhesus antigen in the red blood cells while Rh- indicates the absence of rhesus antigen in the red blood cells.