Which of the following statements about the DNA in one of your brain cells is true?
a. Most of the DNA codes for protein.
b. The majority of genes are likely to be transcribed.
c. It is the same as the DNA in one of your liver cells.
d. Each gene lies immediately adjacent to an enhancer.
The DNA in all the cells of an organism are the same. The reason there are different types of cells in the organism even through their DNA is the same is because genes are deferentially expressed in the cell types. The genes that are expressed in the brain cells are different from those expressed in the liver. The rest of the genes that are not being expressed are silenced through folding by histones – so they are not exposed to DNA polymerase.
