Answer:
The statement is true
Explanation:
Hematopoietic stem cells give rise to myeloid progenitor and lymphoid progenitor and these two progenitors give rise to many immune cells. Dendritic cells are produced by both the progenitors and macrophages are produced by myeloid progenitor.
Both macrophages and dendritic cells are phagocytes. In phagocytosis, the foreing particles are injected by these phagocytes and they are destryoyed by the action of digestive enzymes present in these phagocytic cells.
Macrophages are present in tissue and if they are present in blood they are called monocytes. Therefore the statement is true.
Answer:
d. Two of the above explanations are correct.
Explanation:
A frameshift mutation is commonly known as a genetic mutation that occurs as a result of the indels such as the addition or removal of certain nucleotides in the sequence of a DNA that is indivisible by three. In the presence of addition or removal, the reading frame from the initial translation to a different one. Thus, the correct option is option d.
2009 is the year that the population of zebras and lions is the highest
Answer:
The acidity level of water is measured by the pH scale. Pure water has a pH of 7, which is neutral. However, natural rainwater actually has a pH of 5.6 because it gets exposed to the gases in the atmosphere, making it a bit acidic. True acid rain will have a pH level measuring from 5.0-5.5.