Specialised cells mean they have one specific job, for example cells in the alveoli (in the lungs) would be specialised to transfer oxygen into the blood. An unspecialised cell would be an embryonic stem cell which can become any cell to suit the needs of the organism, which is how a small cluster of cells in a zygote becomes a full human with all the organs and such.
Answer:
Microbiologists are essential in helping us to treat diseases. Many work as biomedical scientists in hospitals and laboratories: testing samples of body tissue, blood and fluids to diagnose infections, monitor treatments or track disease outbreaks.
Plants necessarily must perform ALL of these functions to maintain homeostasis.
All cells come from pre existing cells because if the cells never existed, then the cells could never be created. Cells multiply, from one another constantly forming from cells before them.