I think D is the right answer.
Answer:
I am pretty sure.. it's option B.
COBALT.
I believe animals that possess homologous structures probably evolved from the same ancestor. Homologous structures are similar because of common ancestry. A homologous structure is an example of an organ or bone that appears in different animals, underlining anatomical commonalities demonstrating descent from a common ancestor.
Answer:
Bone marrow.
Explanation:
Hematopiesis may be defined as the formation of the blood cells by the precursor stem cells. This process occurs in the bone marrow, thymus and liver.
The red blood cells are enucleated cells with the minimum span of around 120 days. These cells are processed and destroyed in the spleen. The iron is recovered from the red blood cells and sent again into the bone marrow for the production of new blood cells.
Thus, the answer is bone marrow.
Answer:Wildebeest are considered keystone species because their presence has myriad effects on the ecosystem, unlike those of any other species. Wildebeest are the "lawnmowers" of the Serengeti grassland. They keep grass short which in turn reduces the frequency of fires.
