Do unicellular organisms have skin cells?
No, unicellular is defined as "one cell" so the organism is only made of one cell.
Mitosis in multicellular organisms allows the organism to have more cells, and to replace cells that died or were lost(like an open wound--blood cells would be lost). This is different from the purpose of unicellular organisms because mitosis in unicellular organisms allows reproduction to create more (identical) organisms. replaces damaged cells such as skin cells that are damaged when you get a cut! - reidellen
specialized cells are cells that exist for a specific function for example skin cells or brain cells or liver cells. all multicellular organisms have specialized cells. unicellular organisms do not because they have to carry out all the functions of an entire organism while a skin cell does not have to "worry" about cleaning toxins from the body for example.
All the bacteria and archea are unicellular organisms without nucleus. For example streptococcus pneumoniae is one of them. Unicellular organisms, such as these bacteria, are referred to as Prokaryotic, or as Prokaryotes. These terms refer to all cells and Unicellular organisms without a nucleus or membrane-bound organelles. They contrast to eukaryotes, which do have a nucleus and membrane-bound organelles. For example, humans are made of eukaryotic cells,
Organisms can range being singled (unicellular) to the Earth's largest mammals. Furthermore, you can have organisms within organism such as unicellular healthy gut bacteria living in complex multicelled humans. Moreover, the human immune system is composed of single celled organisms of Killer T-Cells showing a multicelled organism can be further made of unicellular organisms also.