Xenograft means:

Options

A. A graft between two genetically identical individuals
B. A graft in which tissue is grafted from one individual to another individual of same species
C. A graft between individuals of different species
D. Tissue grafted from one area to another area of same individual

Answer

**Step-by-Step Solution:**

1. **Understanding the Term "Xenograft":**
- The term "xenograft" is derived from two parts: "xeno" and "graft."
- "Xeno" refers to "different" or "foreign," while "graft" refers to a tissue or organ that is transplanted.

2. **Definition of Graft:**
- A graft is a piece of living tissue that is transplanted from one site to another, either within the same individual or between different individuals.

3. **Types of Grafts:**
- There are different types of grafts based on the source of the tissue:
- **Autograft:** Tissue grafted from one part of an individual's body to another part of the same individual.
- **Isograft:** Tissue grafted between genetically identical individuals (e.g., identical twins).
- **Allograft:** Tissue grafted between individuals of the same species but who are not genetically identical (e.g., human to human).
- **Xenograft:** Tissue grafted between individuals of different species (e.g., pig heart valve transplanted into a human).

4. **Identifying the Correct Option:**
- Given the definitions, we can analyze the options provided:
- **Option 1:** A graft between two genetically identical individuals (Isograft).
- **Option 2:** A graft between individuals of the same species (Allograft).
- **Option 3:** A graft between individuals of different species (Xenograft).
- **Option 4:** A tissue grafted from one area to another of the same individual (Autograft).
- The correct answer is **Option 3**, which defines a xenograft as a graft between individuals of different species.

5. **Conclusion:**
- Therefore, a xenograft specifically refers to the transplantation of an organ or tissue from one species to another.