Embryoid is

Options

A. A miniature embryo
B. Non-zygotic embryo formed in vitro culture
C. Embryo raised in culture medium
D. Cellular aggregate similar to embryo in appearance.

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Embryoid":**
- An embryoid refers to a structure that resembles an embryo but is not formed through the typical fertilization process.

2. **Identifying Characteristics of Embryoid:**
- An embryoid is a three-dimensional structure that contains pluripotent cells, which means these cells have the potential to differentiate into various cell types.

3. **Formation of Embryoid:**
- Embryoids are formed in vitro (in a controlled environment outside of a living organism) through culture techniques rather than from a zygote (the fertilized egg).

4. **Analyzing the Options:**
- **Option A:** Miniature embryo - This is not accurate as embryoids are not miniature versions of embryos formed through fertilization.
- **Option B:** Non-zygotic embryo formed in vitro culture - This is correct as it describes the embryoid accurately.
- **Option C:** Embryo raised in culture medium - This is misleading because it implies that the embryo comes from a zygote.
- **Option D:** Cellular aggregate similar to embryo in appearance - While this may describe some aspects of an embryoid, it does not capture the essence of its formation and characteristics.

5. **Conclusion:**
- Based on the analysis, the correct answer is **Option B: Non-zygotic embryo formed in vitro culture**.