Which of the following best describes how a liver cell
and skin cell have the exact same DNA sequence and
yet look different and perform different functions?
(1 point)
The tRNA uses a different sequence in
each cell during transcription.
The cells mutate during transcription.
The cells discard the DNA that is not in
use.
The proteins are expressed differently in
each cell.
The proteins are expressed differently in each cell.
The proteins are expressed differently in each cell.
The best answer to this question is: The proteins are expressed differently in each cell.
Explanation:
Despite having the same DNA sequence, liver cells and skin cells look different and perform different functions because they express different proteins. Gene expression is the process by which the instructions encoded in a gene's DNA sequence are used to synthesize a protein. Each cell type in our body has the ability to express different sets of genes and produce different proteins. This regulation of gene expression allows cells to differentiate and specialize into specific cell types, each with its unique characteristics and functions.
The process of gene expression involves two main steps: transcription and translation. During transcription, the DNA sequence of a gene is transcribed into RNA by an enzyme called RNA polymerase. The resulting RNA molecule, known as messenger RNA (mRNA), carries the genetic code from the DNA to the ribosomes in the cytoplasm. However, it is important to note that while the DNA sequence is the same in liver cells and skin cells, the mRNA transcripts produced during transcription can differ between these cell types.
Once the mRNA reaches the ribosomes, translation occurs, where the mRNA is used as a template to synthesize a specific protein. Different sets of proteins are produced in different cell types based on the specific mRNA transcripts present. This means that liver cells and skin cells will have different proteins expressed, which leads to their unique characteristics and functions.
In summary, even though liver cells and skin cells may have the same DNA sequence, they look different and perform different functions because they express different proteins. The process of gene expression, specifically the production of different mRNA transcripts and the subsequent translation into proteins, is what allows cells to differentiate and fulfill their specific roles in the body.