Which of the following statements correctly describes an organism's genome?

• A. It includes only the mitochondrial DNA in eukaryotes.
• B. It is the complete set of DNA, including all of its genes, present in an organism.
• C. It refers only to the protein-coding regions of an organism's DNA.
• D. It is the collection of all RNA molecules found in a cell.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definition of a genome. The genome of an organism is the complete set of genetic material present in a cell or organism.
2. Step 2: Recognize that the genome includes all DNA sequences, not just specific parts. This means it contains both coding regions (genes) and non-coding regions.
3. Step 3: Note that in eukaryotes, the genome includes nuclear DNA as well as mitochondrial DNA, so it is not limited to only mitochondrial DNA.
4. Step 4: Differentiate between DNA and RNA. The genome refers to DNA, not RNA molecules, which are products of gene expression.
5. Step 5: Conclude that the correct description of an organism's genome is that it is the complete set of DNA, including all of its genes, present in an organism.