Answer:
Many plant crops need more phosphorus than is dissolved in the soil to grow optimally. In addition, crops are usually harvested and removed – leaving no decaying vegetation to replace phosphorus. Therefore, farmers replenish the phosphorus ‘pool’ by adding fertilisers or effluent to replace the phosphorus taken up by plants.
Explanation:
Ok i just took this exam the above answer was wrong the real answer should be: More investigations must be completed.
Answer:
d. A centrifuged sample of blood would yield a composition of 45% plasma and 55% cells
Explanation:
Blood is a mixture of plasma and formed elements. Plasma consists of the fluid portion of the blood and approximately makes up 55 percent of the blood. On the other hand, the formed elements are the red blood cells, white blood cells, and platelets which make up about 45 percent of blood.
This occurs through the process of cell specialization, where in some cells genes are active whereas in others they are not.