Some research suggests that individuals who take both vitamin c and zinc at the onset of the common cold experience fewer cold symptoms and recover more quickly than individuals who do not take these nutrients. what is the best explanation of why vitamin c and zinc could reduce the intensity and duration of the common cold? a. vitamin c and zinc are required for the absorption of iron, which is needed by the immune system. b. both vitamin c and zinc are involved in immune system functions. c. vitamin c and zinc are required for the absorption of vitamin k, which is needed for wound recovery. d. both vitamin c and zinc are involved in wound recovery.

Cladistics is a way of classifying organisms by examining the characteristics of their ancestors and descendants and depicting the relationships in a cladogram. which of the following best describes a challenge in classifying organisms this way? a. there are millions of species on earth, and a cladogram is not a practical means for classifying all of them. b. it is impossible to tell which organisms are most closely related to each other using a cladogram. c. cladograms are detail-oriented and do not provide a useful understanding of evolutionary relationships. d. there is a limited number of ways to organize the information, so most cladograms end up looking very similar.