All of the following statements regarding diatom are true, EXCEPT:
Diatoms are microscopic unicellular or colonial algae. It has a cell wall which is strongly impregnated with silica and contain chlorophyll and diatomin, a brown pigment. Diatoms secrets a hard silicaceous outer box like skeleton called a frustulae. They are heat and acid resistant. Ref:The Essentials of Forensic Medicine and Toxicology By Dr K S Narayan Reddy, Pages 329-30
Diatoms are aquatic unicellular plants
Diatoms have an extracellular coat composed of magnesium
Acid digestion technique is used to extract diatoms
Presence of diatoms in the femoral bone marrow is an indication of antemoem inhalation of water