Dark bands of myofibrils are known as____band.

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the name of the dark bands in myofibrils.

2. **Understand Myofibrils**: Myofibrils are the basic rod-like units of a muscle cell, composed of repeating sections called sarcomeres.

3. **Differentiate Bands**: In myofibrils, there are two types of bands: A bands and I bands.

4. **Define A Bands**: The dark bands in myofibrils are known as A bands. These bands are also referred to as anisotropic bands.

5. **Explain A Bands**: A bands are formed in regions where thick myosin filaments are present. This is why they appear darker under a microscope.

6. **Contrast with I Bands**: In contrast, the lighter bands are called I bands, which are isotropic and contain thin actin filaments.

7. **Final Answer**: Therefore, the dark bands of myofibrils are known as A bands.

**Final Answer**: Dark bands of myofibrils are known as A band.

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