Answer:
The correct option is A. Polycythemia Vera
Explanation:
Polycythemia vera is a myeloproliferative disorder of bone marrow hematopoietic cells that causes excessive production of all types of blood cells.
Primary erythrocytosis occurs as a result of polycythemia vera, in this myeloproliferative disorder the bone marrow produces too many red blood cells along with excessive amounts of white blood cells and platelets. Bone marrow under normal conditions produces blood cells and contains the precursor cells of the three series: red blood cells, white blood cells or leukocytes and platelets or thrombocytes, this disorder is characterized by excessive or uncontrolled proliferation or growth of these cells. The increased production of red blood cells or erythrocytes is called erythrocytosis.
Organisms that survive a new environment are said to have adapted to their surroundings.
Answer: Availability of water
Explanation:
When a person is travelling from a forest ecosystem towards grassland ecosystem the number of trees gets reduced in number.
The trees are replaced by prairie grasses. This change is because of less water availability in the area having grass.
The amount of precipitation decides the type of vegetation found in that area.So the area having trees would be having more precipitation as compared to the area having prairie grass.
Abiotic. The sun is not living nor has it ever lived.
