Ptolemy's model had Earth at the center, and the moon's revolved around the planets instead of the planets revolving around the moon and sun. The planets' orbits' moved instead of the planets as well. Geocentric has Earth at the center and heliocentric has the Sun at the center
The answer should be photosphere zone.
Answer:
Cytotoxic T cell
Helper T cell
Explanation:
Adaptive immune system is a part of the immune system initiated only when there is an attack by a pathogen or foreign substance. The adaptive immune system is beckoned on when the infection is insurmountable for the body's first line of immunity, which is the innate immune system.
The adaptive immune response is triggered by the white blood cells called LYMPHOCYTES. Lymphocytes consists of T cells and B cells. T cells are either cytotoxic or helper T cells. The cytotoxic T cells kills the cells infected with the virus while the Helper T cells activate every other cell involved in the immune process.
<span>To determine population size one must have an effective way to count individuals in a given area. This can be challenging since individuals move and may be accounted for multiple times, therefore skewing the final results. Population density requires one to also calculate the area in which the population resides. This is relatively simple to do, but if individuals then exit or enter the calculated area, then the population density changes.</span>
