Toxic elements such as mercury and arsenic are found in the human body because

Toxic elements such as mercury and arsenic are
  found in the human body because
  a. of contamination from the environment.
  b. trace amounts of these elements have vital
  biological functions.
  c. they are needed to kill bacteria.
  d. they may be ingested with food but inactivated
  by cells.
  e. in small amounts they are biologically inactive
  and tolerated by cells.

Question 2

matching the descriptions with the
  most appropriate group listed below.
  a. Bacteria
  b. Protista
  c. Plantae
  d. Fungi
  e. Animalia
  E 88. multicellular producers
  E 89. prokaryotic
  M 90. unicellular organisms of considerable internal
  complexity
  M 91. multicellular motile consumers
  E 92. oldest living organisms
  M 93. unicellular producers
  M 94. multicellular decomposers