Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates, but not by other organisms such as bacteria or plants? A) calcium B) iodine C) sodium D) phosphorus

B) Iodine

Explanation:

Iodine is related with plants and bacteria is in the form of antiseptic, to eliminate microorganisms, but is not linked to either metabolism.

Calcium, sodium and potassium are nutrients directly linked to the metabolism of bacteria and the formation of chemical compounds for various reactions in bacterial cells.

In plants, calcium is primarily responsible for plant structure and cell wall formation. Potassium is important for controlling the amount of water in plants and for activating various enzymes. The function of phosphorus is related to the formation of chemical bonds and sometimes it can be used as an energy reserve.

B) Iodine

Explanation:

Some mineral elements are required in very low quantities by humans, but they are essential for growth, development and nutritional quality, for example, iodine (I), zinc (Zn), and selenium (Se). Nutritionally deficits of these elements are considered a public health problem. However, iodine is an element that works as an antiseptic, which means it kills microbes, penetrating the cell wall and inactivating cell components, its use in medicine is well known. On the other hand, Calcium, Sodium, and Phosphorus, are elements that are fundamental for both humans, plants, and microbes.