Mendel could not find recombination and crossing over as

Options

A. Traits he chose were either present on different chromosomes or were far apart
B. Traits chosen by him were not influenced by gene
C. He did not have a high power microscope
D. He selected only pure types.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks why Mendel could not observe recombination and crossing over in his experiments.

2. **Identifying Mendel's Traits**: Mendel selected seven pairs of contrasting traits for his experiments. These traits were either located on different chromosomes or were situated far apart on the same chromosome.

3. **Defining Recombination and Crossing Over**: Recombination is the process that produces new combinations of traits due to crossing over, which occurs during the pachytene stage of prophase I in meiosis. Crossing over is more likely to occur between genes that are located close to each other on the same chromosome.

4. **Analyzing the Distance of Traits**: Since the traits Mendel chose were either on different chromosomes or far apart on the same chromosome, the likelihood of crossing over occurring between them was minimal. This distance meant that the genes did not influence each other, leading to independent assortment.

5. **Conclusion**: Because the traits were either on different chromosomes or far apart, Mendel observed only the expected parental and recombinant phenotypes without the effects of recombination and crossing over.

6. **Final Answer**: The correct reason Mendel could not find recombination and crossing over is that the traits he chose were either present on different chromosomes or were far apart.

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