Comparison of nitrogenous bases and structural differences between DNA and RNA.

You've provided a clear and well-structured question set comparing DNA and RNA, including labeling of nitrogenous bases and filling in blanks for comparison. Let's go through each part step by step to confirm and explain the correct answers.

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✔ Q.3: Label the names of the nitrogenous bases in DNA and RNA

This diagram shows the structure of DNA (double helix) and RNA (single strand) with their respective nitrogenous bases.

#### 🔹 DNA (Deoxyribonucleic acid)
The four nitrogenous bases in DNA are:
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)

> These pair as:
> - A ↔ T (adenine with thymine)
> - C ↔ G (cytosine with guanine)

#### 🔹 RNA (Ribonucleic acid)
The four nitrogenous bases in RNA are:
- Adenine (A)
- Uracil (U) *(replaces Thymine)*
- Cytosine (C)
- Guanine (G)

> These pair as:
> - A ↔ U (adenine with uracil)
> - C ↔ G (cytosine with guanine)

✔ So your labels are correct:
- DNA: Adenine, Cytosine, Guanine, Thymine
- RNA: Adenine, Cytosine, Guanine, Uracil

> 💡 Note: The only difference is that thymine (T) in DNA is replaced by uracil (U) in RNA.

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✔ Q.4: Fill in the blanks to compare DNA and RNA

| Feature | DNA | RNA |
|--------|-----|-----|
| ➤ A nucleic acid, called ___ | deoxyribonucleic acid | ribonucleic acid |
| ➤ The sugar in DNA is ___ | deoxyribose | ribose |
| ➤ DNA is ___ stranded | double | single |

✔ All your answers are correct!

Let’s break it down:

1. Name of nucleic acids:
- DNA = Deoxyribonucleic Acid
- RNA = Ribonucleic Acid

2. Sugar component:
- DNA contains deoxyribose sugar (has one less oxygen atom than ribose).
- RNA contains ribose sugar (has a hydroxyl group at the 2' carbon).

3. Strandedness:
- DNA is typically double-stranded, forming a double helix.
- RNA is usually single-stranded, though it can fold into complex secondary structures.

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📌 Summary of Key Differences Between DNA and RNA:

| Feature | DNA | RNA |
|--------|-----|-----|
| Sugar | Deoxyribose | Ribose |
| Bases | A, T, C, G | A, U, C, G |
| Strands | Double-stranded | Single-stranded |
| Stability | More stable | Less stable (due to 2'-OH group) |
| Location | Nucleus (mostly) | Nucleus & cytoplasm |
| Function | Stores genetic information | Involved in protein synthesis (mRNA, tRNA, rRNA, etc.) |

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✔ Final Answer:

Your responses to both questions are completely correct! Well done.

If this was a worksheet or exam, you would receive full marks.

Let me know if you'd like a visual summary or mnemonic to remember these differences!