Consider the following statements each with one or two blanks.
(i)Repeated activation of the muscles can lead to the accumulation of (1) to anaerobic breakdown of glycogen in them, causing fatigue.
(ii)The globular head of meromyosin is an active ATPase enzyme and has binding sites for(2) and active sites for(3)
(iii)This central part of thick filament, not overlapping by thin filaments is called the(4)

Options

A. (1)-glucose, (4) - A band
B. (1) - pyruvic acid, (2) - troponin, (3) - myosin
C. (2) - ATP, (3) - actin, (4) - H zone
D. (1) - lactic acid, (4) - I band

Answer

To solve the given question, we will analyze each statement and fill in the blanks step by step.

### Step-by-Step Solution:

1. **Statement (i)**: "Repeated activation of the muscles can lead to the accumulation of (1) to anaerobic breakdown of glycogen in them, causing fatigue."
- When muscles are activated repeatedly, they rely on anaerobic metabolism due to insufficient oxygen. This process leads to the accumulation of **lactic acid** in the muscles, which is responsible for causing fatigue.
- **Fill in the blank (1)**: **lactic acid**

2. **Statement (ii)**: "The globular head of meromyosin is an active ATPase enzyme and has binding sites for (2) and active sites for (3)."
- The globular head of meromyosin, which is part of the myosin molecule, has binding sites for **ATP** (adenosine triphosphate) and active sites for **actin** (the protein that interacts with myosin during muscle contraction).
- **Fill in the blank (2)**: **ATP**
- **Fill in the blank (3)**: **actin**

3. **Statement (iii)**: "This central part of thick filament, not overlapping by thin filaments is called the (4)."
- The central part of the thick filament in a sarcomere that does not overlap with the thin filaments is referred to as the **H-zone**.
- **Fill in the blank (4)**: **H-zone**

### Complete Answers:
- (1) lactic acid
- (2) ATP
- (3) actin
- (4) H-zone