PSI Barbering Practice Exam

Which are single-celled microorganisms that exhibit both plant and animal characteristics?

1. Protozoa

2. Viruses

3. Bacteria

4. Fungi

The correct answer is: Protozoa

The correct answer refers to protozoa, which are indeed single-celled microorganisms that display characteristics typical of both plants and animals. They belong to the kingdom Protista and are primarily classified as eukaryotic organisms. This means they have complex cells with a defined nucleus and organelles. Protozoa often exhibit animal-like behaviors, such as movement and predation, as they can capture and ingest other microorganisms and organic matter for nourishment. Certain protozoa, such as Euglena, contain chloroplasts and can perform photosynthesis, akin to plant life. This dual nature allows protozoa to adapt to various environments, thrive as consumers, and also produce energy through photosynthesis when necessary. In contrast, viruses are not classified as living organisms since they cannot reproduce or carry out metabolic processes on their own and rely on host cells for replication. Bacteria are unicellular but are prokaryotic, lacking a true nucleus and organelles typical of eukaryotic cells. Fungi, while also eukaryotic, are generally multicellular and exhibit characteristics distinct from either plants or animals. This context emphasizes why protozoa are classified as the organisms that embody both plant and animal features.