How is it possible that cells with the same genes can be different?

Answer 1

It's a bit more tricky than what Mandy and the others mention, although it is always connected with differences in gene expression.

First of all you have two types of variation:

The first has been discussed in the previous answers. That is why cells in a multi-cellular organism like humans, although they all have the same genes there are different cell types. Cell diferentiation is based on the regulation of gene expression. Cells that belong to different tissues express different genes. Lot's of different mechanisms for that.

The second type is variation within cells of the same type. You can see this very clearly in uni-cellular organisms like bacteria: sometimes you can expose a homogeneous bacterial population to a certain chemical signal and the response of some cells can be very different leading to more than one sub-populations. This is called noise in gene expression, is a function of many things like the very small number of some regulating molecules and it also depends sometimes on cellular memory.

I don't know your background so I'll refrain from entering into more specialized stuff.

Answer 2

because they can talk to each other with chemicals and receptors. Receptor activation can regulate which genes are active and what cell proteins are made. The early cells tell the later ones what they should do next (what kind of tissue they will be)
All this is stored in the genes which are a equal combination from the mother and the father.
This process is called developmental embryology and every step is critical and often goes wrong and may result in a miscarriage

Answer 3

All tough the cell in the living things divide in under the organelles and gene duplication, but that cell is also naturally pass through the following phases. There are the Synthesis-Phase and the 'checkpoint phases'. And also that daughter cell is also passing through the cell specialization process. And also the protein afterward that that cell will obtained is different according to the environment. So that is why that cell is different.

Answer 4

because different cells use different genes at different times...

all cells contain all genes, but not all cells use all genes....they turn the genes that they need on or off when they need them

Answer 5

Yes... your cells all have the same genetic code but they differentiate, or specialize to preform different functions.

Answer 6

Mandy gets a gold star!!