Which of the following statements correctly distinguishes DNA from RNA?

• A. DNA contains the sugar deoxyribose, while RNA contains the sugar ribose.
• B. DNA contains the base uracil, while RNA contains the base thymine.
• C. DNA is usually single-stranded, while RNA is usually double-stranded.
• D. DNA is found only in the cytoplasm, while RNA is found only in the nucleus.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the structural differences between DNA and RNA. DNA (deoxyribonucleic acid) contains the sugar deoxyribose, whereas RNA (ribonucleic acid) contains the sugar ribose. The difference lies in the presence or absence of an oxygen atom on the sugar molecule.
2. Step 2: Examine the nitrogenous bases present in DNA and RNA. DNA contains the bases adenine (A), thymine (T), cytosine (C), and guanine (G). RNA contains adenine (A), uracil (U), cytosine (C), and guanine (G). Note that thymine is replaced by uracil in RNA.
3. Step 3: Consider the strand structure of DNA and RNA. DNA is typically double-stranded forming a double helix, while RNA is usually single-stranded, allowing it to fold into various shapes.
4. Step 4: Identify the cellular locations of DNA and RNA. DNA is primarily located in the nucleus of eukaryotic cells, while RNA is synthesized in the nucleus but functions mainly in the cytoplasm.
5. Step 5: Use these distinctions to evaluate the given statements and determine which correctly differentiates DNA from RNA based on sugar type, bases, strand structure, and cellular location.