A multicellular organism is made up of more than one cell. Humans, animals, and plants are all examples of multicellular organisms. Groups of cells form tissue, groups of tissue forms organs, groups of organs form systems.
Unicellular organisms receive material directly from their environment. Multicellular organisms have systems for moving materials throughout their body. Unicellular organisms can perform all of life’s functions within a single cell. Multicellular organisms have many cells that each perform a special function. Cells develop into their mature forms through the process of cell differentiation. Cells differ because different combinations of genes are expressed. Organs are groups of tissues that perform a specific or related function. Organ systems are groups of organs that carry out similar functions.
For example, stem cells are classified into three types: totipotent (or growing into any other cell type), pluripotent, or growing into any cell type but a totipotent cell), multipotent (or growing into cells of a closely related cell family).
The DTI technique is useful for examining the brain. It is a used to observe the neuropathology and associated treatment. It is used to examine the pathology of brain such as axonal damage, edema, inflammation, and iscemia myelination.
