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?
The phase during which sister chromatids aggregate along the equator of the cell is called the metaphase.
The image shows the process of cell division through mitosis. The mother cell divides into two genetically identical daughter cells in mitosis. There are four main phases in the mitosis process. They are: prophase, metaphase, anaphase and telophase. In the metaphase, the highly condensed sister chromatids line up along the equator of the cell by binding to the microtubles that form the skeleton of the cell. These kinetochores line up the chromatids at the equator to initiate their separation.
Every cell of the organism has the same DNA sequence and same genes. However, not all genes are expressed in every single cell at the same time. Only those genes necessary for a specialised function of a specialised cell are expressed in the specialised cell. For example, skin cells have some different proteins than nerve cells. Genes responsible for those "skin proteins" are activated in skin cells and are turned off in nerve cells.
