Cell Differentiation and Specialization - Unit 5 PDF

Cell Differentiation Every cell in a multicellular organism contains all genes of that organism. Not all genes are activated in every cell The genes that are activated encode for proteins Proteins affect the structure and function of cells By activating...

Cell Differentiation Every cell in a multicellular organism contains all genes of that organism. Not all genes are activated in every cell The genes that are activated encode for proteins Proteins affect the structure and function of cells By activating certain genes and not others, the cells are able to differentiate and form specialized tissues. Undifferentiated cells use ‘signals’ or ‘cues’ to begin the process of differentiation. These cues may come from other cells or from within the cell itself. Remembering terminology... Stem cells can be either: Totipotent Pluripotent Multipotent “whole” “many” “several” Can become any Can become any Has partially body cell body cell (but differentiated but (including not placenta). can still become placenta in multiple, related The inner cell placental cell types. mass of a mammals). blastocyst is Umbilical cord A zygote is pluripotent. stem cells are totipotent. multipotent. As stem cells differentia te, they begin to express some genes but not others. Regenerat ive Medicine Using Stem Cells