Cross between unrelated group of organisms is called

Options

A. Hybridisation
B. Heterosis
C. test cross
D. Back cross.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the term that describes the cross between unrelated groups of organisms.

2. **Analyzing the Options**: The options provided are:
- A) Hybridization
- B) Heterosis
- C) Test cross
- D) Back cross

3. **Evaluating Option A - Hybridization**:
- Hybridization refers to the process of crossing two different organisms, which can be unrelated. This can occur within the same species (intraspecific) or between different species (interspecific). The offspring produced from this cross are known as hybrids. Therefore, this option is a strong candidate.

4. **Evaluating Option B - Heterosis**:
- Heterosis, also known as hybrid vigor, is the phenomenon where hybrid offspring exhibit superior qualities compared to their parents. It does not specifically refer to the act of crossing unrelated organisms, so this option is not correct.

5. **Evaluating Option C - Test Cross**:
- A test cross is a breeding experiment used to determine the genotype of an individual by crossing it with a homozygous recessive individual. This involves related organisms, so this option is also incorrect.

6. **Evaluating Option D - Back Cross**:
- A back cross involves crossing a hybrid organism back to one of its parents or to an individual genetically similar to its parent. This is also a cross between related organisms, making this option incorrect.

7. **Conclusion**: After evaluating all options, the correct answer is **A) Hybridization**, as it specifically refers to the cross between unrelated groups of organisms.

**Final Answer**: The cross between unrelated groups of organisms is called **Hybridization**.

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