AP BIOLOGY

Detailed explanation-1: -Gene regulation is how a cell controls which genes, out of the many genes in its genome, are “turned on” (expressed). Thanks to gene regulation, each cell type in your body has a different set of active genes – despite the fact that almost all the cells of your body contain the exact same DNA.

Detailed explanation-2: -How can a person’s muscle cells have the same exact DNA sequences as their nerve cells even thought they look and perform completely different? The proteins expressed in each cell are different. In living organisms, the cell cycle is closely regulated.

Detailed explanation-3: -What causes DNA instructions to make a muscle cell instead of a nerve cell? The muscle cell and nerve cell inherit different DNA sequences. Transcription of different genes leads to the synthesis of different proteins in the two cell types.

Detailed explanation-4: -These cells are different because they use the same set of genes differently. So even though each of our cells has the same 20, 000 or so genes, each cell can select which ones it wants to “turn on” and which ones it wants to keep “turned off”.

Detailed explanation-5: -All the cells of higher organisms have the same DNA but not the same proteins. Each type of specialised cell that forms a tissue has its own pattern of gene expression and, consequently, it contains a particular set of proteins that determine its function.