The right answer is D.
The absorption of molecules at the level of the skin is carried out by passive diffusion for the molecules of low molecular weight (lower than 400 Da), the skin being covered with a lipoprotein film rich in water by its stratum corneum, rendering it little-permeable.
This absorption may be variable according to factors related to the skin such as stratum corneum's thickness, the state of hydration, the presence of cutaneous lesions or individual variations.
External factors may also modulate percutaneous absorption such as contact time, iontophoresis or the presence of specific adjuvants.
Answer:
Nitrogen is so vital because it is a major component of chlorophyll, the compound by which plants use sunlight energy to produce sugars from water and carbon dioxide (i.e., photosynthesis). It is also a major component of amino acids, the building blocks of proteins. Without proteins, plants wither and die.
Calcium is few of the main sources for healthy bones, teeth, and muscles.
Chronic lymphocytic leukemia or the CLL is among the most common type of leukemia affecting the adults. The lymphocytic leukemia starts in the lymphocytes. Lymphocytic leukemia is different from the lymphoma (which also occur in the lymphocytes) as it only occurs in the bone marrow and the blood. The person suffering from CLL is susceptible to an array of infections. Among the various infectious agents, the CLL patient is the most susceptible to the Staphylococcus aureus. This agent causes skin infections, pneumonia, toxic shock syndrome and many other life threatening diseases. The person becomes susceptible to its attack as the immunity of his is weakened beacuse of the damage to the lymphoctic cells.