List two structural adaptations in straited muscle fibres to draw more energy.

Explanation

### Step-by-Step Text Solution:

1. **Understanding Striated Muscle Fibers**: Striated muscle fibers, also known as skeletal muscles, are characterized by their striations (ribbon-like structures) and are under voluntary control. They are multi-nucleated and unbranched.

2. **Adaptation 1: High Vascularity**: One key structural adaptation of striated muscle fibers is their high vascularity. This means that they have a rich supply of blood vessels. The increased blood supply ensures that more oxygen and nutrients are delivered to the muscle fibers, which is essential for energy production.

3. **Adaptation 2: Abundance of Mitochondria**: Another important adaptation is the large number of mitochondria present in striated muscle fibers. Mitochondria are known as the "powerhouses" of the cell because they are responsible for producing ATP (adenosine triphosphate), the energy currency of the cell. More mitochondria mean that the muscle fibers can produce more ATP, leading to increased energy availability for muscle contraction.

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