Other than pea plants it was found that sometimes the `F_(1)` had phenotype that did not resemble either of the two parents and was in between the two. It is due to

Options

A. Complete Dominance
B. Incomplete dominance
C. Co-Dominance
D. Complementary gene interaction

Answer

**Step-by-Step Solution:**

1. **Understanding the Phenotype of F1 Generation:**
- The question states that the F1 generation has a phenotype that does not resemble either of the two parents and is intermediate between the two. This indicates that the inheritance pattern is not typical dominance.

2. **Identifying the Type of Inheritance:**
- The scenario described suggests a case of incomplete dominance. In incomplete dominance, the phenotype of the heterozygous genotype is a blend of the phenotypes of the two homozygous parents.

3. **Example of Incomplete Dominance:**
- A classic example of incomplete dominance is found in the plant Mirabilis jalapa (commonly known as the four o'clock plant). In this plant, the red-flowered variety can be represented as RR (homozygous), and the white-flowered variety as rr (homozygous).

4. **F1 Generation in Mirabilis Jalapa:**
- When these two varieties are crossed (RR x rr), the F1 generation consists of all heterozygous individuals (Rr). The phenotype of the F1 generation is pink flowers, which is intermediate between the red and white flowers.

5. **Phenotypic Ratio in F2 Generation:**
- If the F1 generation (Rr) is self-fertilized, the F2 generation will have a phenotypic ratio of 1 red (RR) : 2 pink (Rr) : 1 white (rr). This reinforces the concept of incomplete dominance.

6. **Conclusion:**
- Therefore, the phenomenon where the F1 generation has a phenotype that is intermediate between the two parents is due to incomplete dominance.

**Final Answer:**
The F1 phenotype that does not resemble either parent and is intermediate is due to **incomplete dominance**.

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