What is false about the nucleic material in differentiated cells of a multicellular organism?

In differentiated cells of a multicellular organism, it is true that all cells share identical DNA, as they originate from a single zygote and maintain the same genetic material throughout development. However, the key aspect is how this identical DNA is utilized; while the genetic information remains the same, different cell types can express different genes based on their specific functions and roles within the organism.

For instance, a muscle cell will express genes necessary for muscle contraction, while a nerve cell will express genes important for neurotransmission. This differential gene expression is crucial for the specialization of cells.

Regarding the other options, DNA sequences remain unchanged in differentiated cells, meaning that the underlying genetic code does not alter simply because cells have differentiated into specific types. Additionally, DNA replication is indeed essential for cell division, allowing the genetic information to be accurately passed on to daughter cells.

This context reinforces why the assertion that "all cells have identical DNA" might lead to misunderstandings about how gene expression varies in different cell types, even when the underlying genetic code is the same.