Arginine and lysine are …..A……. proteins and found abundantly in ……B……..
Choose the correct option for A and B.

Options

A. A-acidic, B-protamine
B. A-basic, B-histone proteins
C. A-acidic, B-histone proteins
D. A-neutral, B-histone proteins

Answer

To solve the question, we need to identify the correct terms for the blanks A and B in the statement: "Arginine and lysine are …..A……. proteins and found abundantly in ……B……."

### Step-by-Step Solution:

1. **Identify the Nature of Arginine and Lysine**:
- Arginine and lysine are amino acids that are positively charged at physiological pH. This characteristic classifies them as basic amino acids.

2. **Fill in Blank A**:
- Since arginine and lysine are positively charged, they are classified as **basic proteins**. Thus, the correct term for blank A is **"basic"**.

3. **Determine Where These Proteins Are Found**:
- Arginine and lysine are abundant in histone proteins, which are involved in the packaging of DNA in eukaryotic cells. Histones are rich in basic amino acids, including arginine and lysine.

4. **Fill in Blank B**:
- Therefore, the correct term for blank B is **"histone proteins"**.

### Final Answer:
Arginine and lysine are **basic** proteins and found abundantly in **histone proteins**.

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