Find out incorrect statements `:-`

Options

A. Brain box is formed of 8 bones
B. In skull the frontal bone is single
C. A single U-shaped bone present at the base of the buccal carity is quadrate
D. Hyoid bond is the part of skull

Answer

To find the incorrect statements regarding the human skeletal system, we will analyze each statement provided in the question step by step.

### Step 1: Analyze the first statement
The first statement mentions that the cranium consists of 8 bones.
- **True**: The cranium is indeed made up of 8 bones: 1 frontal bone, 2 parietal bones, 2 temporal bones, 1 occipital bone, 1 sphenoid bone, and 1 ethmoid bone.

### Step 2: Analyze the second statement
The second statement claims that the frontal bone is single.
- **True**: The frontal bone is a single bone located at the front of the skull.

### Step 3: Analyze the third statement
The third statement states that a single U-shaped bone present at the base of the buccal cavity is quadrate.
- **False**: The U-shaped bone at the base of the buccal cavity is the hyoid bone, not the quadrate bone. The quadrate bone is not present in humans; it is found in some other vertebrates.

### Step 4: Analyze the fourth statement
The fourth statement claims that the hyoid bone is a part of the skull.
- **False**: The hyoid bone is not part of the skull; it is located in the neck and is not directly connected to any other bone.

### Conclusion
Based on the analysis, the incorrect statements are:
1. "A single U-shaped bone present at the base of the buccal cavity is quadrate." (False)
2. "The hyoid bone is a part of the skull." (False)

### Final Answer
The incorrect statements are the third and fourth statements.

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