How can the cells in a multicellular organism differ from each other when they all have identical dna

Well all cells in a multicellular organism have the same exact DNA (except for sex cells). But what makes each type of cell different physically and functionally is the genes that are expressed in those cells.So for like example a different section of the DNA molecule is expressed in a nerve cell than a skin cell.

Well, they serve different purposes. Depending on the type of cell, different cells are affected by different DNA. Stem cells can become any cell type, and are extremely abundant in developing babies. Think of it like the clones in Star Wars, all the same DNA, different jobs.

An egg, or a sack of flour

answer: carbon 14 can only be used to determine the age of the organisms that were once living, and igneous rocks are non living.

explanation:

carbon 14 dating is used to determine the age of the sample by estimating the amount of carbon 14 present in the sample and then comparing it with a reference standard.carbon 14 is a isotope of carbon which is radioactive and unstable. carbon 14 is assimilated by all plants and animals throughout their life from carbon dioxide. however, one the organisms die they stop this assimilation and the carbon 14 content starts to decrease.by knowing how much of carbon 14 is left in an organism after his death, one can estimate the age of the organism. the materials whose age can be estimated by carbon 14 method are the organic compounds. however, some inorganic compounds such as aragonite   shell can also be dated.however, if we consider the igneous rocks it is a non living component which never accumulated carbon 14 in it and thus, we cannot use carbon 14 dating method to estimate its age.