Read the given Statements .
(i) A motor neuron along with the muscle fibres connected to it constitutes a neuromuscular junction.
(ii) During muscles relaxation , `Ca^(++)` are pumped back from sarcoplasm to the cisternae.
(iii) Aerobic muscles have a large number of Mitochondria to utilize a large amount of oxygen for generation of ATP.
(iv) Red muscles have high myoglobin content.
Which of these is/are INCORRECT ?

Options

A. i only
B. i,ii, iv
C. iii, iv
D. None of these

Answer

To determine which of the statements provided are incorrect, we will analyze each statement one by one.

### Step 1: Analyze Statement (i)
**Statement:** A motor neuron along with the muscle fibers connected to it constitutes a neuromuscular junction.

**Analysis:** This statement is incorrect. A motor neuron along with the muscle fibers it innervates forms a motor unit, not a neuromuscular junction. The neuromuscular junction specifically refers to the synapse or connection between the motor neuron and the sarcolemma (muscle cell membrane) of the muscle fiber.

### Step 2: Analyze Statement (ii)
**Statement:** During muscle relaxation, Ca²⁺ ions are pumped back from the sarcoplasm to the cisternae.

**Analysis:** This statement is correct. During muscle relaxation, calcium ions (Ca²⁺) are indeed pumped back into the sarcoplasmic reticulum (cisternae), which helps the muscle fibers to relax after contraction.

### Step 3: Analyze Statement (iii)
**Statement:** Aerobic muscles have a large number of mitochondria to utilize a large amount of oxygen for the generation of ATP.

**Analysis:** This statement is also correct. Aerobic muscles, which rely on oxygen for energy production, possess a high number of mitochondria to facilitate the breakdown of glucose in the presence of oxygen to generate ATP.

### Step 4: Analyze Statement (iv)
**Statement:** Red muscles have high myoglobin content.

**Analysis:** This statement is correct. Red muscles, which are used for endurance activities, contain a high amount of myoglobin, a protein that binds oxygen, thus giving the muscles their red color and enabling them to store oxygen for aerobic respiration.

### Conclusion
After analyzing all four statements:
- Statement (i) is incorrect.
- Statements (ii), (iii), and (iv) are correct.

Thus, the only incorrect statement is (i).

### Final Answer
The answer is: **Only statement (i) is incorrect.**

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