CELL DIVISION
CELL DIVISION AND CANCEROUS CELLS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Different genes are expressed in brain and liver cells.
|
|
|
Brain and liver cells divide at different rates.
|
|
|
Mutations occur more frequently in liver cells than brain cells.
|
|
|
Human brain cells are infected by viruses.
|
Detailed explanation-1: -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-2: -All your cells contain the same genes, but cells don’t make all the proteins they have genes for. Thus, what makes a liver cell different from a brain cell is which proteins it makes-and therefore, which of its genes are turned on.
Detailed explanation-3: -All of the cells within a complex multicellular organism such as a human being contain the same DNA; however, the body of such an organism is clearly composed of many different types of cells.
Detailed explanation-4: -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-5: -For example, one of the jobs of the liver is to remove toxic substances like alcohol from the bloodstream. To do this, liver cells express genes encoding subunits (pieces) of an enzyme called alcohol dehydrogenase. This enzyme breaks alcohol down into a non-toxic molecule.