Glands in a vertabrate body may originate from

Options

A. ectoderm
B. mesoderm
C. ectoderm and endoderm
D. ectoderm, mesoderm and endoderm

Answer

### Step-by-Step Solution:

1. **Understanding Germ Layers**:
- In vertebrates, during the early stages of embryonic development, the zygote undergoes several transformations, leading to the formation of three primary germ layers: ectoderm, mesoderm, and endoderm.

2. **Identifying Gland Types**:
- Glands can be classified into two main types based on their structure:
- **Exocrine glands**: These have ducts and secrete their products into these ducts (e.g., salivary glands).
- **Endocrine glands**: These are ductless and release their hormones directly into the bloodstream (e.g., thyroid gland).

3. **Origin of Glands from Germ Layers**:
- Each of the three germ layers contributes to the formation of different glands:
- **Ectoderm**: Gives rise to glands such as the pituitary and pineal glands.
- **Endoderm**: Forms glands like the pancreas and thyroid gland.
- **Mesoderm**: Contributes to glands such as the kidneys and gonads (ovaries and testes).

4. **Conclusion**:
- Since all three germ layers (ectoderm, mesoderm, and endoderm) can give rise to various glands in the vertebrate body, the correct answer is that glands may originate from all three layers.

5. **Final Answer**:
- The glands in a vertebrate body may originate from **ectoderm, mesoderm, and endoderm**. Therefore, the correct option is **D** (ectoderm, mesoderm, and endoderm).