Answer:
receptor down-regulation
Explanation:
Downregulation is a control mechanism by which a cell decreases the amount of a cellular component, such as RNA or protein, in response to an external variable. In contrast, a reactive increase of a cellular component is called upregulation. An example of downregulation occurs when insulin binds to its receptor and the complex is endocyted in the cell in response to hormonal signaling.
they help us see because the retina also contains the nerves that tell the brian what the photoreceptors are seeing
Answer:
all of the above
Explanation:
Epigenetic alterations are modifications of the genome transmitted during cell division, which do not involve changes in the DNA sequence, are hereditary and are capable of modifying gene expression. In addition, they are temporary modifications that allow DNA to be transcribed and have the ability to move histones to open or close a chromosomal region. There are three main mechanisms of epigenetic alterations: DNA methylation, histone modifications and genomic imprinting.
