Answer :
In a eukaryotic organism, different cell types exhibit certain differences, but there are also fundamental similarities. Let's consider each of the given options to identify what is not a difference between cells in different cell types:
The genes expressed are different in different cell types.
- This is true. Different cell types will express different sets of genes depending on their function. For example, muscle cells express genes related to muscle contraction, while nerve cells express genes related to signal transmission.
The genome is different in different cell types.
- This is false. The genome, which is the complete set of DNA, is the same in all cells of an organism. However, what differs is which genes are expressed, not the underlying genetic code.
The RNA molecules are different between different cell types.
- This is true. Different cell types produce different RNA molecules based on the genes they express. This includes mRNA which translates to proteins, as well as various types of non-coding RNAs.
The proteins present are different between different cell types.
- This is true. Because different cell types express different genes, they will also have different proteins. This specialization allows them to perform their specific functions effectively.
The non-coding RNA genes are different between different cell types.
- This statement might be confusing as non-coding RNA genes themselves do not differ between cell types, but the expression of these RNAs can differ.
Based on these explanations, option 2, "The genome is different in different cell types," is not an accurate statement since the genomic DNA is the same across different cell types within an organism.
Therefore, the correct answer to the question 'What's not a difference between cells in different cell types of one eukaryotic organism?' is option 2.