$ Inharitance of flower colour in mirabilis jalapa is type of polygenic inheritance.
! Polysomes are a type of chromosomes.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

To solve the question regarding the inheritance of flower color in Mirabilis jalapa and the nature of polysomes, we will analyze the assertion and reason step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the inheritance of flower color in Mirabilis jalapa is a type of polygenic inheritance.
- Polygenic inheritance involves multiple genes contributing to a single trait, resulting in a continuous range of phenotypes.

2. **Analyzing the Flower Color in Mirabilis jalapa**:
- Mirabilis jalapa, commonly known as the four o'clock flower, exhibits a variety of flower colors, including yellow, pink, and white.
- However, the inheritance pattern for flower color in this plant is actually an example of **incomplete dominance**, not polygenic inheritance. Incomplete dominance means that when two different alleles are present, the resulting phenotype is a blend of the two traits (e.g., crossing a red flower with a white flower results in pink flowers).

3. **Conclusion on the Assertion**:
- Since the inheritance of flower color in Mirabilis jalapa is not polygenic but rather an example of incomplete dominance, the assertion is **incorrect**.

4. **Understanding the Reason**:
- The reason states that polysomes are a type of chromosomes.
- Polysomes, also known as polyribosomes, are not chromosomes; they are aggregates of ribosomes that are translating mRNA into proteins. They appear as beads on a string, where each bead represents a ribosome and the string is the mRNA strand.

5. **Conclusion on the Reason**:
- Since polysomes are ribosomal structures involved in protein synthesis and not chromosomes, the reason is also **incorrect**.

6. **Final Conclusion**:
- Both the assertion and the reason are incorrect. Therefore, the correct answer is that both the assertion and the reason are wrong.