Skin and nerve cells have different appearances and characteristics from each other, although they contain the same dna. why? a. the genes expressed in in skin cells may not be expressed in nerve cells and vise versa
b. the genes in skin cells are transcribed but not translated as genes of nerve cells
c. the dna in nerve cells undergoes mutations making them different from dna in skin cells.

The correct answer is A. the genes expressed in skin cells may not be expressed in nerve cells and vise versa.

Explanation:

Every cell in the body contains the same set of genes in their chromosomes but only some fraction of its gene expresses which allows the different cells to appear and function differently in their environment.

Therefore every cell makes different proteins according to the job that cell performs like in RBC genes are expressed to synthesize the hemoglobin proteins but other cells do not produce this protein because genes for hemoglobin is not expressed in them.

Therefore the right answer is A. the genes expressed in skin cells may not be expressed in nerve cells and vise Versa.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

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i need an image of the diagram