What are diatoms?

Diatoms are classified as small unicellular organisms that can be found in both fresh and salt water. They are a type of phytoplankton and are characterized by their unique, silica-based cell walls, which can take on a variety of intricate and beautiful shapes. These organisms play a crucial role in aquatic ecosystems, serving as a primary food source for various aquatic organisms. Diatoms are also significant in the context of environmental and forensic science. In forensic investigations, the presence of diatoms in a victim's lungs can help determine if drowning occurred, as they often enter the body when a person drowns in water containing these organisms. This association demonstrates their importance in crime scene investigation and death investigation.

While there are other types of organisms, such as multicellular organisms or large algae, the defining characteristics and relevance of diatoms in both ecological and forensic contexts affirm that they are indeed small unicellular forms, making the choice the most accurate.