Most of the cartilages in vertebrate embryo are replaced in adult by

Options

A. Blood
B. Bones
C. Tendons
D. Ligaments.

Answer

To solve the question "Most of the cartilages in vertebrate embryo are replaced in adult by?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks what replaces the cartilages found in vertebrate embryos as they develop into adults.

2. **Identify the Nature of Cartilage**: Cartilage is a type of dense connective tissue that is present in the skeleton of vertebrate embryos. It serves as a precursor to the adult skeleton.

3. **Recognize the Developmental Process**: In vertebrate development, the majority of the cartilaginous structures are gradually replaced by a more rigid structure, which is bone.

4. **Define Ossification**: The process through which cartilage is replaced by bone is known as ossification. During this process, calcium ions are deposited in the cartilage, leading to its transformation into bone.

5. **Evaluate the Options**:
- **Blood**: Incorrect, as blood is a fluid connective tissue and does not replace cartilage.
- **Bones**: Correct, as bones are formed from the ossification of cartilage.
- **Tendons**: Incorrect, tendons connect muscles to bones and do not replace cartilage.
- **Ligaments**: Incorrect, ligaments connect bones to other bones and also do not replace cartilage.

6. **Conclusion**: Based on the understanding of the developmental process and the evaluation of the options, the correct answer is **bones**.

### Final Answer:
Most of the cartilages in vertebrate embryo are replaced in adult by **bones**.

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