Biochemical function within any cell is determined largely by specific enzymes. Remember, enzymes are proteins. Different sets o
f genes must be turned on and off in the various cell types. This is how cells _______________. (BIO.3C.1) evolve. Reproduce. Differentiate. Produce daughter cells.
Every cell in a multicellular organism has an identical genome, and yet, there are various cell types. These varieties are the result of highly controlled modifications in gene expression (different sets of genes must be turned on and off).
Cellular differentiation almost never involves a change in the DNA sequence itself. Therefore, different cells can have very different physical characteristics regardless of having the same genome.
<u>Explanation</u>: Our bodies come from the fusion of two sex cells that provide the us with a full chromosome set specific to our species. Thus, all the cells in our bodies originate from a single diploid cell formed by the fusion of two gametes.
Inside that cell is the complete blueprint for our bodies encoded in our genes. However, as this cell divides, its offspring will start to fullfill different functions (skin cells, smell receptors, photoreceptors etc.). This is achieved by activating only a specific set of genes. The rest of the genes encoding for other cell types are inactive.
Thus, the ability to turn different sets of genes on or off enables cells to differentiate.
