Question

Consider for a moment the dna in one of your brain cells - which of the following statements is true?

a. the majority of genes are likely to be transcribed.
b. each gene lies immediately adjacent to an enhancer.
c. many genes are grouped into operon-like clusters.
d. most of the dna codes for protein.
e. it is the same as the dna in one of your heart cells.

Answer 1

The DNA in brain cells is the same as that in heart cells, but because each cell type has different functions, they express different subsets of genes. Gene expression is regulated so that only the necessary genes are transcribed and translated into proteins.

Step-by-step explanation:

Considering the DNA in one of your brain cells, it is true that it is the same as the DNA in one of your heart cells. Despite having the same DNA sequences, not all genes are transcribed in every cell type because each cell type has distinct functions and requires a different set of proteins.

For example, the proteins necessary for brain function are different from those needed for cardiac function. As a result, each cell type expresses a unique subset of genes, and gene expression is a highly regulated process that involves transcription of only certain genes to mRNA, which is then translated into the specific proteins needed by that cell.