Answer to Question 1
C
Answer to Question 2
Malnutrition affects all aspects of immunity, including both innate and adaptive immune defenses. For example, both protein-energy malnutrition (PEM) and vitamin A deficiency can result in damage to the skin and mucous membranes, allowing microorganisms to more easily enter the body. Deficiencies of protein and various micronutrients can affect the synthesis of hydrolytic enzymes, complement, antibodies, and other proteins important for immune function. Cell-mediated immunity is impaired in numerous ways by both PEM and zinc deficiencies. Because PEM is usually associated with multiple micronutrient deficiencies, it has been difficult for researchers to separate out the influences of individual nutrients. Nevertheless, zinc, iron, and vitamin A deficiencies are among the most common micronutrient deficiencies worldwide, and a large body of research has demonstrated that each has a strong, independent influence on immunity. Of note, correcting deficiencies of various micronutrients (especially zinc and vitamin A ) in malnourished populations has been found to reduce the incidence and severity of illness.
Normal mammogram.
Blood vessels: (A) normal artery; (B) constriction; (C) arteriosclerosis and atherosclerosis.
Intracellular relationships involving the glyoxylate cycle in plant cells
Normal and thermal inversion air masses interaction
Relative levels of neuronal loss in HD transgenic mice
Group defenses: Cluster of sawfly caterpillars regurgitating fluid (yellow) that predators find unap