Which of the following cellular structures contains RNA but not DNA under typical eukaryotic cell conditions?

• A. Nucleus
• B. Chromosomes
• C. Ribosomes
• D. Mitochondria

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the typical nucleic acid content of each cellular structure listed. The nucleus and chromosomes primarily contain DNA, as chromosomes are DNA-protein complexes located inside the nucleus.
2. Step 2: Recall that mitochondria contain their own DNA and RNA, as they have their own genome and machinery for protein synthesis.
3. Step 3: Recognize that ribosomes are cellular structures responsible for protein synthesis and are composed mainly of ribosomal RNA (rRNA) and proteins, but they do not contain DNA.
4. Step 4: Compare the options and identify which structure contains RNA but lacks DNA under normal eukaryotic cell conditions. Ribosomes fit this description because they have RNA but no DNA.
5. Step 5: Conclude that the correct answer is ribosomes, as they contain RNA but not DNA, unlike the nucleus, chromosomes, and mitochondria.